INTERSTATE COUNCIL FOR STANDARDIZATION, METROLOGY AND CERTIFICATION

INTERSTATE

STANDARD

HIGH PURITY COPPER Photometric methods of analysis

Official edition

Speedartiifoei

Foreword

The goals, basic principles and the basic procedure for carrying out work on interstate standardization are established by GOST 1.0-92 “Interstate standardization system. Basic Provisions” and GOST 1.2-2009 “Interstate Standardization System. Interstate standards. rules and recommendations for interstate standardization. Rules for the development, adoption, application, updating and cancellation "

About the standard

1 DEVELOPED by the Technical Committee for Standardization TC 368 "Copper"

2 INTRODUCED by the Interstate Technical Committee for Standardization MTK 503 "Copper"

3 ADOPTED by the Interstate Council for Standardization, Metrology and Certification (Minutes of August 27, 2015 Ne 79-P)

4 By order of the Federal Agency for Technical Regulation and Metrology of February 17, 2016 No 52-st, the interstate standard GOST 27981.5-2015 was put into effect as the national standard of the Russian Federation from November 1, 2016.

5 83AMEN GOST 27981.S-88

Information about changes to this standard is published in the annual information index "National Standards", and the text of changes and amendments - in the monthly information index "National Standards". In the event of a revision ("replacement") or cancellation of this standard, the corresponding notice will be published in the monthly information index "National Standards". The relevant information, notice and texts are also posted in the public information system - on the official website of the Federal Agency for Technical Regulation and Metrology in the network Internet ()

In the Russian Federation, this standard cannot be fully or partially reproduced. replicated and distributed as an official publication without the permission of the Federal Agency for Technical Regulation and Metrology

INTERSTATE STANDARD

HIGH PURITY COPPER

Photometric methods of analysis

Copper of high purity. Photometric methods of analysis

Introduction date - 2016-11-01

1 area of use

This International Standard specifies photometric methods for the determination of the components in high purity copper listed in Table 1.

Table 1 Percentage

Newly defined component	Range mass fraction of the component	Name defined component	Range mass fraction of the component
	From 0.00020 to 0.0050 per key.		From 0.00010 to 0.0050 inclusive
Manganese	From 0.0002 to 0.0050 inclusive		From 0.00010 to 0.0100 inclusive
	From 0.00002 to 0.0010 acc.		From 0.0003 to 0.010 inclusive
	From 0.00010 to 0.006 inclusive		From 0.00010 to 0.006 inclusive
	From 0.0005 to 0.0050 inclusive		From 0.00010 to 0.006 inclusive

2 Normative references

8 of this standard, normative references to the following interstate standards are used:

GOST 61-75 Reagents. Acetic acid. Specifications

GOST 84-76 Reagents. Sodium carbonate 10-one. Specifications

GOST 123-2008 Cobalt. Specifications

GOST 849-2008 Primary nickel. Specifications

GOST 859-2014 Copper. Stamps

GOST 860-75 Tin. Specifications

GOST 1089-82 Antimony. Specifications

GOST 1770-74 (ISO 1042-83. ISO 4788-80) Measuring laboratory glassware. Cylinders. beakers, flasks, test tubes. "General specifications

GOST 1973-77 Arsenic anhydride. Specifications GOST 3118-77 Reagents. Hydrochloric acid. Specifications

GOST 3652-69 Reagents. Citric acid monohydrate and anhydrous. Specifications

GOST 3760-79 Reagents. Ammonia water. Specifications

GOST 3765-78 Reagents. Ammonium molybdate. Specifications

GOST 3773-72 Reagents. Ammonium chloride. Specifications

GOST 4197-74 Reagents. Sodium aeotoxide. Specifications

GOST 4198-75 Reagents. Potassium phosphate one-substituted. Specifications

Official edition

GOST 4204-77 Reagents. Sulfuric acid. Specifications GOST 4232-74 Reagents. Potassium iodide. Specifications GOST 4328-77 Reagents. sodium hydroxide. Specifications GOST 4461-77 Reagents. Nitric acid. Specifications GOST 4465-74 Reagents. Nickel (U) sulfate 7-eone. Specifications GOST 5456-79 Reagents. Hydroxylamine hydrochloride. Specifications GOST ISO 5725*6-2003 Accuracy (correctness and precision) of measurement methods and results. Part 6. Using Precision Values in Practice*

GOST 5789-78 Reagents. Toluene. Specifications GOST 5817-77 Reagents. Tartaric acid. Specifications GOST 5828-77 Reagents. Dimethylglyoxime. Specifications GOST 5841-74 Reagents. Hydrazine sulfate

GOST 5845-79 Reagents. Potassium-sodium tartrate 4-water. Specifications GOST 5846-73 Reagents. Formic acid. Specifications GOST 5955-75 Reagents. Benzene. Specifications GOST 6006-78 Reagents. Butanol-1. Specifications

GOST 6008-90 Metallic manganese and nitrided manganese. Specifications GOST 6259-75 Reagents. Glycerol. Specifications.

GOST 6552-80 Reagents. Phosphoric acid. Specifications

GOST 6563-75 Technical products from noble metals and alloys. Specifications

GOST 6691-77 Reagents. Urea. Specifications

GOST 6709-72 distilled water. Specifications

GOST 9147-80 Laboratory porcelain glassware and equipment. Specifications GOST 9428-73 Reagents. Silicon (IV) oxide. Specifications GOST 9849-86 Iron powder. Specifications GOST 10298-79 Technical selenium. Specifications

GOST 10652-73 Reagents. Disodium salt ethylenediamine-N. N. N "N"-tetraacetic acid. 2-water (trilon B). Specifications

GOST 10928-90 Bismuth. Specifications

GOST 10929-76 Reactants. Hydrogen peroxide. Specifications

GOST 11069-2001 Primary aluminum. Stamps

GOST 11125-84 High purity nitric acid. Specifications

GOST 11773-76 Reagents. Sodium phosphate disubstituted. Specifications

GOST 12026-76 Laboratory filter paper. Specifications

GOST 14261-77 High purity hydrochloric acid. Specifications

GOST 18300-87 Rectified technical ethyl alcohol. Specifications ’

GOST 19807-91 Wrought titanium and titanium alloys. Grades GOST 20015-88 Chloroform. Specifications

GOST 20288-74 Reagents. Carbon tetrachloride. Specifications GOST 20478-75 Reagents. Ammonium persulphate. Specifications GOST 20490-75 Reagents. Potassium permanganate. Specifications GOST 22280-76 Reagents. Sodium citrate 5.5-aqueous. Specifications GOST 22867-77 Reagents. Ammonium nitrate. Specifications GOST 24104-2001 Laboratory balance. General technical requirements *

GOST 24363-80 Reagents. potassium hydroxide. Specifications

GOST 25336-82 Laboratory glassware and equipment. Types, basic parameters and dimensions

GOST 29169-91 (ISO 648-77) Laboratory glassware. Pipettes with one mark

GOST 29227-91 (ISO 835-1-81) Laboratory glassware. Pipettes graduated. Part 1. General requirements

GOST 29251-91 (ISO 385*1-84) Laboratory glassware. Burettes. Part 1. General requirements

GOST 31382-2009 Copper. Analysis Methods

Note - When using this standard, it is advisable to check the validity of reference standards in the public information system - on the official website of the Federal Agency for Technical Regulation and Metrology on the Internet or according to the annual information index "National Standards", which was published as of January 1 of the current year, and on issues of the monthly information index "National Standards" for the current year. If the reference standard is replaced (modified), then when using this standard, you should be guided by the replacing (modified) standard. If the referenced standard is canceled without replacement, the provision in which the reference to it is given applies to the extent that this reference is not affected.

3 General

3.1 General requirements for measurement methods - according to GOST 31382.

4 Photometric method for measuring the mass fraction of bismuth

4.1 Characteristics of measurement accuracy indicators

Measurement accuracy indicators of the mass fraction of bismuth correspond to the characteristics given in Table 2 (at P - 0.95;.

The values of the limits of repeatability and reproducibility of measurements at a confidence level P = 0.95 are given in Table 2.

Table 2 - Values of the indicator of accuracy, limits of repeatability and reproducibility of measurements of the mass dopi of bismuth at a confidence level P = 0.95

Measurement range of mass fraction of bismuth	Accuracy index 1 L	(absolute values)
Measurement range of mass fraction of bismuth	Accuracy index 1 L	repeatability	reproducibility
From 0.00020 to 0.00050 inclusive
Se. 0.0005 » 0.0010 »
» 0.0010 » 0.0020 »
» 0.0020 » 0.0050 »

4.2 Measuring instruments, auxiliary devices, materials, solutions

Spectrophotometer or photocolorimeter with all accessories, providing measurements at a wavelength of 450 nm;

Heating plate according to 4]. providing a heating temperature of up to 400 C. or similar;

Watch glass;

Volumetric flasks 2-25-2.2-100-2. 2-250-2.2-1000-2 lo GOST 1770;

Glasses H-1-100 THS, N-1-400 THS according to GOST 25336;

Conical flasks Kn-2*250 THS according to GOST 25336;

Conical funnels B-36-80 XC lo GOST 25336;

Distilled water according to GOST 6709:

Nitric acid according to GOST 4461 or high purity nitric acid according to GOST 11125;

Hydrochloric acid according to GOST 3118. diluted 1:1;

Tartaric acid according to GOST 5817. solution of mass concentration 250 g / dm 3:

Ascorbic acid according to (2): freshly prepared solution of mass concentration 50 g/dm 3 ;

Water ammonia according to GOST 3760, diluted 1:99;

Iron powder according to GOST 9849. solution of mass concentration 10 g / dm 3;

Potassium iodide according to GOST 4232. freshly prepared solution of mass concentration 200 g/dm 3 ;

Bismuth according to GOST 10928:

Filters de-aerated according to or similar.

Notes

1 It is allowed to use other measuring instruments of approved types, auxiliary devices and materials, the technical and metrological characteristics of which are not inferior to those indicated above.

2 It is allowed to use reagents manufactured according to other regulatory documents, provided that they provide the metrological characteristics of the measurement results given in this standard.

4.3 Measurement method

The method is based on the measurement of optical density at a wavelength of 420 to 450 nm of a colored bismuth iodine complex formed in a hydrochloric acid solution in the presence of tartaric acid and a reducing agent.

Bismuth is additionally isolated on iron hydroxide.

4.4 Preparing to take measurements

4.4.1 Preparation of solutions for building a calibration curve

When preparing solution A, a mass concentration of bismuth of 0.1 mg/sh e, a sample of bismuth weighing 0.1000 g is placed in a beaker with a capacity of 100 cm 3, 5 to 10 cm 3 of nitric acid is added, and heated to remove nitrogen oxides. The solution is cooled and transferred to a volumetric flask with a capacity of 1000 cm 3 , 65 cm 3 of nitric acid are added, topped up with water to the mark and mixed.

When preparing solution B, the mass concentration of bismuth is 0.01 mg/cm3, an aliquot of 25 cm3 of solution A is placed in a 250 cm3 volumetric flask, 5 cm3 of nitric acid is added, topped up with water to the mark, and mixed.

The solution is suitable for use within 5 hours.

4.4.2 Preparation of a solution of iron with a mass concentration of 10 g / dm 3

A portion of iron weighing 1.0 g is placed in a glass with a capacity of 100 cm 3 . pour from 10 to 15 cm 3 hydrochloric acid and dissolve when heated. After cooling, the solution is transferred into a volumetric flask with a capacity of 100 cm 3 , topped up with water to the mark and mixed.

4.4.3 Building a calibration curve

In six conical flasks with a capacity of 250 cm 3 each place 0.0; 1.0; 2.0; 3.0; 4.0 and 5.0 cm 3 of solution B. which corresponds to 0.0 0.01; 0.02; 0.03; 0.04 and 0.05 mg of bismuth, pour 5 cm 3 of nitric acid. 20 cm 3 hydrochloric acid. The pores are heated and evaporated to a volume of 3 to 5 cm 3 . 5 cm 3 of an iron solution are poured, from 100 to 120 cm 3 of water, heated to a temperature of 60 * C to 70 * C and ammonia is added until copper passes into the ammizd complex and after that another 5 cm 3. Heating is continued for 5-7 minutes and the solution is left until the precipitate coagulates in a warm place on the stove.

The hydroxide precipitate is filtered onto a loose filter and washed 3 to 5 times with hot ammonia diluted 1:99. The precipitate from the filter is washed off into the flask in which the precipitation was carried out, and from 15 to 20 cm 3 of hot hydrochloric acid, diluted 1:1, is poured. The resulting solution is diluted with water to a volume of 80 to 106 cm 3 and the hydroxides are again precipitated with ammonia. The precipitate is filtered onto the same filter and washed 3 to 4 times with hot ammonia diluted 1:99. A funnel with a filter is placed over the flask in which precipitation was carried out, from 10 to 15 cm 3 of hot hydrochloric acid diluted 1:1 is added to the precipitate, the filter is washed 2-3 times with hot water. The filter is discarded. The filtrate is evaporated to a volume of 10 cm 3 , after cooling it is placed in a volumetric flask with a capacity of 25 cm 3 , 4 cm 3 of tartaric acid solution is added. 5 cm 3 of a solution of potassium iodide, from 1.0 to 1.5 cm 3 of a solution of ascorbic acid and add water to the mark.

After 10-15 minutes, the optical density of the solutions is measured on a spectrophotometer or photocolorimeter at a wavelength of 420 to 450 nm in a cuvette with an optimal layer thickness. The reference solution is water.

Based on the obtained values of optical densities and the corresponding bismuth concentrations, a calibration graph is built.

4.5 Taking measurements

A sample of copper weighing 2.0000 g is placed in a beaker with a capacity of 400 cm 3 , 25 to 30 cm 3 of nitric acid is added, covered with a watch glass and kept without heating until the violent reaction of nitrogen oxide evolution stops.

The glass is removed, washed with water over the glass, 20 to 25 cm 3 of hydrochloric acid are poured in and the solution is evaporated when heated to a volume of 3 to 5 cm 3 .

Then, st 80 to 100 cm 3 of water and 5 cm 3 of iron solution are poured into a glass. Heat up and then continue the measurement as indicated in 4.4.3.

measurements are carried out in accordance with the instructions for use of the spectrophotometer or photocolorimeter, the mass of bismuth is set according to the calibration graph.

4.6 Processing measurement results

4.6.1 Mass fraction of bismuth X.%. calculated according to the formula

(gm>!-/p2)100 mlO®

where m, is the mass of bismuth found from the calibration curve, μg; m2 is the mass of bismuth obtained as a result of a blank experiment, μg; m is the weight of the sample of copper. G.

4.6.2 The arithmetic mean of two parallel determinations is taken as the measurement result, provided that the absolute difference between them under repeatability conditions does not exceed the values (at a confidence level P = 0.95) of the repeatability limit r given in Table 2.

4.6.3 The discrepancies between the measurement results obtained in two laboratories should not exceed the values of the reproducibility limit given in Table 2. In this case, their arithmetic mean value can be taken as the final result. If this condition is not met, the procedures set out in GOST ISO 5725-6 (clause 5.3.3) can be used.

5 Photometric method for measuring the mass fraction of manganese

5.1 Characteristics of measurement accuracy indicators

The accuracy of measurements of the mass fraction of manganese correspond to the characteristics given in table 3 (at P - 0.95;.

The values of the limits of repeatability and reproducibility of measurements at a confidence level of P-0.95 are shown in Table 3.

Table 3 - Values of the indicator of accuracy, limits of repeatability and reproducibility of measurements of the mass fraction of manganese at a confidence level P = 0.95

Mass fraction measurement range of manganese	Accuracy index 1 L	(absolute values)
Mass fraction measurement range of manganese	Accuracy index 1 L	repeat mi axis r (l "2)	reproducibility
From 0.0002 to 0.0005 inclusive
Se. 0.0005 » 0.0010 »
» 0.0010 » 0.0020 »
» 0.0020 » 0.0050 »

5.2 Measuring instruments, auxiliary devices, materials, solutions

When performing measurements, the following measuring instruments and auxiliary devices are used:

Heating plate according to . providing heating temperature up to 400 "C. or similar:

water bath;

Laboratory scales of a special accuracy class according to GOST 24104;

Glasses N-1-100 THS. H-1-250 THS according to GOST 25336:

Conical flasks Kn-1-250-14/23 THS according to GOST 25336;

Volumetric flasks 2-50-2.2-100-2.2-1000-2 according to GOST 1770;

Pipettes not lower than the 2nd accuracy class according to GOST 29169 and GOST 29227.

When performing measurements, the following materials and solutions are used:

Nitric acid according to GOST 4461 or special purity nitric acid according to

GOST 11125 and diluted 1:1.1:3;

Potassium iodate by. solution of mass concentration 50 g / dm 3:

Metal manganese according to GOST 6008.

Notes

5.3 Measurement method

The method is based on the measurement of the optical density of a colored complex compound of heptavalent manganese at a wavelength of 520 to 540 nm.

5.4 Preparing to take measurements

5.4.1 Preparation of solutions for building a calibration curve

When preparing solution A, a mass concentration of manganese of 0.1 mg / cm 3, a weighed portion of manganese weighing 0.1 g is placed on a beaker with a capacity of 100 cm 3, from 10 to 15 cm 3 of nitric acid diluted 1:1 is poured. heated to remove nitrogen oxides. The solution is cooled, transferred to a volumetric flask with a capacity of 1000 ml Oe and topped up with water to the mark.

When preparing solution B, the mass concentration of manganese is 0.01 mg/cm 3 an aliquot of 10 cm 3 of solution A is placed in a volumetric flask with a capacity of 100 cm 3, 1 cm 3 of nitric acid diluted 1:1 is added. and top up with water to the mark.

When preparing a solution C of mass concentration of 0.005 mg/cm 3 an aliquot of 50 cm 3 of solution B is placed in a volumetric flask with a capacity of 100 cm 3 , 0.5 cm 3 of nitric acid diluted 1:1 is added. and top up to the mark.

5.4.2 Preparation of a solution of potassium iodate, mass concentration 50 g / dm 3

A portion of potassium iodate weighing 50 g is dissolved in a solution of nitric acid, diluted

1:3. and drink up to 100 cm 3 with the same solution.

5.4.3 Building a calibration curve

In glasses with a capacity of 250 cm 3 each place 0.0; 1.0; 2.0 and 5.0 cm 3 of solution B and 1.0:2.0; 3.0:

4.0 and 5.0 cm 3 of standard solution B. which corresponds to 0.0; 0.005; 0.010; 0.025:0.100:0.200; 0.300; 0.400; 0.500 mg of manganese. Water is poured into all glasses to a volume of 20 cm 3, then boiled for 5 minutes.

5 cm 3 of potassium iodide solution are poured into the boiling solution and boiling is continued for another 5 minutes. Then the beaker is placed in a boiling water bath and incubated for 20 minutes.

After cooling, transfer the solution to a volumetric flask with a capacity of 50 cm 3, add water to the mark (basic solution) and mix.

The optical density of solutions is measured on a spectrophotometer at a wavelength of 530 nm or a photocolorimeter with a light filter having a wavelength corresponding to the maximum light transmission from 520 to 540 nm in a cuvette with a layer thickness of 20 or 30 mm.

The reference solution is part of the main sample solution, in which manganese (VII) is reduced to manganese (H) by adding 1 to 2 drops of sodium nitrite solution.

Based on the obtained values of the optical densities of the solutions and the corresponding concentrations of manganese, a calibration graph is built in rectangular coordinates.

5.5 Taking measurements

A portion of copper weighing 2.000) g (with a mass fraction of manganese from 0.0002% to 0.001%) or 1.0000 g (with a mass fraction of manganese from 0.001% to 0.005%) is placed in a conical flask with a capacity of 250 cm 3, poured from 20 to 25 cm 3 nitric acid and boil until the vigorous reaction of nitrogen oxide evolution and dissolution of the sample ceases. The solution is evaporated to half and then continued as described in 5.4.3.

measurements are carried out in accordance with the instruction manual for the spectrophotometer or photocolorimeter, and the mass of manganese in milligrams is set according to the calibration graph.

5.6 Processing measurement results

5.6.1 Mass fraction of manganese X, %. calculated according to the formula

(tu -/t)2)100 /7)1000

where mi is the mass of manganese found from the calibration curve, mg; m2 is the mass of manganese obtained as a result of a blank experiment, mg; m is the mass of the sample of copper. G.

5.6.2 The arithmetic mean of two parallel determinations is taken as the measurement result, provided that the absolute difference between them under repeatability conditions does not exceed the values (at a confidence level P - 0.95) of the repeatability limit r given in Table 3.

If the discrepancy between the largest and smallest results of parallel determinations exceeds the value of the repeatability limit, perform the procedures described in GOST ISO 5725-6 (subclause 5.2.2.1).

5.6.3 Differences between the results of measurements obtained in two laboratories should not exceed the values of the limit of eoetria. given in Table 3. In this case, their arithmetic mean value can be taken as the final result. If this condition is not met, the procedures in ISO 12b-b, OC I, b.3.3, may be used.

6 Photometric method for measuring the mass fraction of cobalt

6.1 Characteristics of measurement accuracy indicators

The accuracy indicators of measurements of the mass fraction of cobalt correspond to the characteristics given in table 4 (at P - 0.95;.

The values of the limits of repeatability and reproducibility of measurements at a confidence level P - 0.95 are given in Table 4.

Table 4 - Values of the accuracy index, recombustibility limits and reproducibility of measurements of the mass fraction of cobalt at a confidence level P = 0.95

In percentages

6.2 Measuring instruments, auxiliary devices, materials, solutions

When performing measurements, the following measuring instruments and auxiliary devices are used:

Spectrophotometer or photocolorimeter with all accessories capable of measuring at a wavelength of 410 nm;

Heating plate according to (1]. providing heating temperature up to 400 "C. or similar:

Watch glass:

Laboratory scales of a special accuracy class according to GOST 24104;

Conical flasks Kn-2-250-18 THS according to GOST 25336;

Volumetric flasks 2-100-2.2-500-2 according to GOST 1770;

Glasses H-1-50 THS. H-1-100 THS according to GOST 25336;

Dividing funnels VD-1-250 (100) XC according to GOST 25336;

Pipettes not lower than the 2nd accuracy class according to GOST 29169 and GOST 29227.

When performing measurements, the following materials and solutions are used:

Distilled water according to GOST 6709;

Nitric acid according to GOST 4461 (boiled to remove nitrogen oxides), diluted 1:1;

Hydrochloric acid according to GOST 3118 and a solution of a molar concentration of 4 mol / dm 3;

Citric acid according to GOST 3652. solution of mass concentration 250 g / dm 3;

Potassium hydroxide according to GOST 24363, solution of mass concentration 50 g/dm 3 ;

Acetic acid according to GOST 61;

Aluminum according to GOST 11069;

Toluene according to GOST 5789;

1-nitroso-2-naphthol according to . solution of mass concentration 0.5 g/dm 3 ;

Hydrogen peroxide according to "OST 10929 (stabilized product);

Cobalt according to GOST 123;

Copper according to GOST 859. not containing cobalt.

Notes

1 It is allowed to use from other measuring instruments of approved types, auxiliary devices and materials, the technical and metrological characteristics of which are not inferior to those indicated above.

2 It is allowed to use reagents manufactured according to other regulatory documents, provided that they provide the metrological characteristics of the measurement results given in this standard.

6.3 Measurement method

The method is based on measuring the optical density at a wavelength of 410 nm of a colored cobalt compound with 1-nitroso-2-chaftol after its extraction with toluene and preliminary separation of copper on metallic aluminum.

6.4 Preparing to take measurements

6.4.1 Preparation of solutions for building a calibration curve

When preparing solution A, the mass concentration of cobalt is 1.0 mg/cm 3, a sample of metallic cobalt weighing 0.1000 g is placed in a beaker with a capacity of 100 cm 3, 20 cm 3 of a mixture of nitric and hydrochloric acids are poured (e ratio 1:3). heated to remove nitrogen oxides. The solution is evaporated to wet salts. Pour in 1C cm 3 hydrochloric acid and evaporate to dryness. Treatment with hydrochloric acid is repeated 2 more times.

From 30 to 50 cm 3 of hot water is poured to the dry residue, cooled, transferred to a volumetric flask with a capacity of 100 cm 3, topped up with water to the mark and mixed.

When preparing solution B, the mass concentration of cobalt is 0.01 mg/cm 3 an aliquot of 5 cm 3 of solution A is placed in a volumetric flask with a capacity of 500 cm 3, topped up with water to the mark and mixed.

When preparing solution B, the mass concentration of cobalt is 0.001 mg/cm 3, I place an aliquot of 10 cm 3 of solution B in a measuring flask with a capacity of 100 cm 3, add water to the mark and mix. The solution is used freshly prepared.

When preparing solution D, the mass concentration of cobalt is 0.0001 mg/cm 3, an aliquot of 10 cm 3 of solution 8 is placed in a measuring tube with a capacity of 100 cm 3, topped up with water to the mark and mixed. The solution is used freshly prepared.

6.4.2 Building a calibration curve

6.4.2.1 Construction of a calibration curve for a mass fraction of cobalt from 0.00002% to 0.0001%.

To two weights of copper mass 1.0000 g (for each of the points of the calibration graph) add 2.0; 3.0; 4.0; 5.0 and 10.0 cm 3 of G.'s solution, which corresponds to 0.0002; 0.0003; 0.0004; 0.0005 and 0.0010 mg of cobalt and then continue measurements as indicated in 6.5.1.

Based on the obtained values of optical density and the corresponding cobalt concentrations, a calibration graph is built.

6L2.2 Construction of a calibration curve with a mass fraction of cobalt from 0.0001% to 0.0005%.

To two weighed portions of copper weighing 1.0000 g (for each of the points of the calibration graph), 1.0 and 5.0 cm 3 of solution B and 1.0 are poured; 2.5; 5.0 cm 3 of solution B. which corresponds to 0.001; 0.005: 0.010:0.025 and 0.050 mg cobalt and beyond continue measurements as specified in 6.5.1.

6.4.2.3 Preparation of 1-nitroeo-2-naphthol solution, mass concentration 0.5 g/dm*

A portion of the reagent weighing 0.25 g is dissolved in 50 cm 3 of a solution of potassium hydroxide with a mass concentration of 50 g / dm 3, placed in a volumetric flask with a capacity of 500 cm 3, 100 cm 3 of acetic acid is added, diluted with water to the mark and mixed.

6.5 Taking measurements

6.5.1 A sample of copper weighing 1.0000 g is placed in a conical flask with a capacity of 250 cm3, 15 cm3 of nitric acid diluted 1:1 is added and heated until the sample is dissolved and nitrogen oxides are removed. The solution is evaporated on n / mtv with asbestos to a volume of 2 cm * and then treated three times with hydrochloric acid in portions of 10 cm * to completely remove nitrogen oxides, evaporating twice to wet salts, and the last time to dryness. 100 cm 3 of water are added to the dry residue and heated until the salts dissolve.

8, the solution is injected with 7 to 8 granules of metallic aluminum, the total mass of which is from 3.5 to 4.0 g, and heated at a temperature of 80 ° C to 90 ° C for 2 to 3 hours until copper is completely isolated (the solution should be transparent without blue tint).

After cementation of copper, the solution is transferred by decantation into a beaker with a capacity of 100 cm 3, the walls of the flask and the released copper are carefully washed with water, adding washing water to the main solution in such a way. so that copper does not get into the solution, and evaporated on asbestos to a volume of 20 to 30 cm 3.

After cooling, a mixture of 5 cm * citric acid solution and 10 cm 3 1-nitroeo-2-naphthol solution is added to the solution with stirring (the mixture is prepared before adding for each sample). The solution is neutralized with tableted potassium hydroxide to pH 4.0 to 4.5. heated to boiling and add 0.3 cm 3 hydrogen peroxide. The beaker is covered with a watch glass, the solution is boiled for 10 minutes and then cooled to room temperature.

The solution is poured into a separating funnel with a capacity of 10 cm 3 , 10 cm * of toluene is added and extracted for 2 minutes. The extract is washed with 10 cm3 of hydrochloric acid with a molar concentration of 4 mol/dm* for 1 min. then 10 cm 3 of a solution of potassium hydroxide with a mass concentration of 50 g / dm * for 1 min. The extract is poured into a dry glass and the optical density is measured on a spectrophotometer or photocolorimeter at a wavelength of 410 nm in a cuvette with a layer thickness of 20 mm. The reference solution is toluene.

The measurements are carried out in accordance with the instructions for use of the spectrophotometer or photocolorimeter, the mass of cobalt in milligrams is set according to the calibration graph.

6.5.2 Conducting a blank test

Copper, released on aluminum, free from cobalt, is dissolved in nitric acid, diluted 1:1. The solution is evaporated to a volume of 2 to 3 cm 3 and then continued as described in 6.5.1.

6.6 Processing measurement results

6.6.1 Mass fraction of cobalt X.%. calculated according to the formula

where mi is the mass of cobalt in the solution of the analyzed sample, μg;

m 2 is the mass of bismuth obtained as a result of a blank experiment, mcg; m is the weight of the sample of copper. G.

6.6.2 The arithmetic mean of two parallel determinations is taken as the measurement result, provided that the absolute difference between them under repeatability conditions does not exceed the values (at a confidence level P - 0.95) of the repeatability limit r given in Table 4.

6.6.3 The discrepancies between the measurement results obtained in two laboratories should not exceed the values of the reproducibility limit given in Table 4. In this case, their arithmetic mean value can be taken as the final result. If this condition is not met, the procedures set out in GOST ISO 5725-6 (clause 5.3.3) can be used.

7 Photometric method for measuring the mass fraction of arsenic

7.1 Characteristics of measurement accuracy indicators

The accuracy of measurements of the mass fraction of arsenic correspond to the characteristics given in table 5 (at R-095).

The values of the limits of repeatability and reproducibility of measurements at a confidence level P - 0.95 are given in Table 5.

Table 5 - Values of the indicator of accuracy, limits of repeatability and reproducibility of measurements of the mass fraction of arsenic at a confidence level Р = 0.95

In percentages

Mass fraction measurement range of arsenic	Index ACCURACY i l	(absolute values)
Mass fraction measurement range of arsenic	Index ACCURACY i l	repeatability	reproducibility
From 0.00010 to 0.00030 inclusive
St. 0.00030 » 0.00060 »
» 0.0006 » 0.0012 »
» 0.0012 » 0.0030 »
» 0.003 » 0.006 »

7.2 Measuring instruments, auxiliary devices, materials, solutions

When performing measurements, the following measuring instruments and auxiliary devices are used:

Spectrophotometer or photocolorimeter with all accessories capable of measuring at a wavelength of 610 nm;

Heating plate according to (1]. providing heating temperature up to 400 *C. or similar:

Laboratory scales of a special accuracy class lo GOST 24104;

Glasses H-1-250 THS. M-400 THS. V-1-250 THS. V-1-400 THS lo GOST 25336:

Dividing funnels VD-1-250 XC, VD-1-1000 XC according to GOST 25336;

Conical flasks Kn-2-500-24/29 THS; Kn-2-750-24/29 THS according to GOST 25336;

Volumetric flasks 2-50-2.2-100-2.2-200-2 according to GOST 1770;

Kjeldahl flask according to GOST 25336;

Funnels for filtering laboratory lo GOST 25336;

water bath;

Buechner funnels according to GOST 9147.

When performing measurements, the following materials and solutions are used;

Distilled water according to GOST 6709;

High purity nitric acid according to GOST 11125 or GOST 4461. distilled, diluted 1:1;

Sulfuric acid according to GOST 4204. diluted 1:3 and 1:10. solutions of molar concentration of 0.5 and 3 mol / dm 3:

Hydrochloric acid of special purity according to GOST 14261. Density 1.19 g/cm3, diluted 1:1. solution of molar concentration 9 mol / dm 3:

Potassium iodide according to GOST 4232:

Carbon tetrachloride according to GOST 20288. distilled;

Rectified technical ethyl alcohol according to GOST 18300:

Ammonium molybdate according to GOST 3765. solution 10 g / dm 3 in a solution of sulfuric acid 3 mol / dm 3:

Hydrazine sulfate according to GOST 5841. solution of mass concentration 5 g / dm 3:

Ferroammonium alum according to . solution of mass concentration 100 g / dm 3:

Sodium carbonate 10-water according to GOST 84. saturated solution:

Sodium hydroxide according to GOST 4328. solution of molar concentration 1 mol / dm 3:

Potassium permanganate then GOST 20490. solution of molar concentration 0.06 mol / dm 3;

Ammonium chloride according to GSTS 3773. solution of mass concentration 20 g / dm 3;

Titanium trichloride according to (7], solution of mass concentration 400 g/dm 3 ;

Titanium according to GOST 19807:

Arsenic anhydride according to GOST 1973;

Filters de-aerated according to or similar.

Notes

7.3 Measurement method

The method is based on the photomegrification of a colored arsenic-molybdenum complex. Arsenic is first isolated with ammonia by precipitation together with iron hydroxide and subsequent extraction of arsenic with carbon tetrachloride.

7.4 Preparing to take measurements

741 Invite rlptiorlp for plg.trllliii coming airlylchnlgl schedule

When preparing solution A, the mass concentration of arsenic is 0.1 mg / cm 3, a sample of arsenic anhydride weighing 0.0266 g is placed in a volumetric flask with a capacity of 200 cm 3, 2 cm 3 of sodium hydroxide solution and 50 cm 3 of water are added, stirred until the sample is dissolved. After that, 3 cm 3 of a solution of sulfuric acid with a molar concentration of 0.5 mol/dm 3 are added. Dilute to the mark with water and mix.

When preparing solution B, the mass concentration of arsenic is 0.01 mg/cm3, an aliquot of 10 cm3 of solution A is placed in a volumetric flask with a capacity of 100 cm3, topped up with water to the mark, and mixed.

7.4.2 Building a calibration curve

8 seven volumetric flasks with a capacity of 50 cm 3 each placed 0.0; 0.5:1.0; 1.5; 2.0; 2.5; and 3.0 cm 3 of solution B. which corresponds to 0.00; 0.005; 0.010; 0.015: 0.020; 0.025 and 0.030 mg of arsenic. 8 Add 40 ml of water to each flask and continue as described in 7.5. The reference solution is an arsenic-free solution.

Based on the obtained values of ethical densities and the corresponding mass fractions of arsenic, a calibration graph is built in rectangular coordinates.

7.4.3 Preparation of a solution of hydrochloric acid with a molar concentration of 9 mol / dm 3

When preparing a solution of hydrochloric acid with a molar concentration of 9 mol / dm 3, the acid is purified from arsenic: 10 g of potassium iodide is dissolved in 500 cm 3 of hydrochloric acid, the solution is transferred to a separating funnel with a capacity of "000 cm 3, 25 cm 3 of carbon tetrachloride is added, shaken for After settling, the organic layer is discarded.Then, 25 cmOe of carbon tetrachloride is added to the solution in a separating funnel and shaken for 2 minutes.The organic layer is discarded.Purification of the acid is carried out before use.

7.4.4 Preparation of a solution of ammonium molybdate, mass concentration 10 g / dm 3

When preparing a solution of ammonium molybdate with a mass concentration of 10 g / dm 3, the reagent is recrystallized twice from an alcohol solution before use: a 70 g sample of salt is placed in a conical flask with a capacity of 750 cm 3, 400 cm 3 of hot water is added and filtered twice through a dense filter. To the filtrate is poured 250 cm 3 of ethanol and incubated for 1 h at room temperature, after which the crystals are sucked off on a Buchner funnel. The resulting ammonium molybdate is dissolved and recrystallized again. The crystals are again sucked off on a Buechner funnel, washed 2-3 times with ethyl alcohol in portions from 20 to 30 cm 3 , after which the crystals are dried in air.

7.4.5 When preparing a solution of molybdate hydrazine, 50 cm 3 of a solution of ammonium molybdate is placed in a volumetric flask with a capacity of 100 cm 3, 5 cm 3 of a hydrazine solution is added, topped up with water to the mark and mixed. The solution is used freshly prepared.

7.4.6 When preparing a solution of iron ammonium alum, a 10 g sample of salt is placed in a glass with a capacity of 25C cm 3, 5 cm 3 of nitric acid and 70 cm 3 of water are added. The solution is heated until the sample is dissolved, cooled and filtered through a medium density filter. The filter is discarded. and the filtrate is diluted with water to a volume of 100 cm 3 .

7.4.7 When preparing a solution of titanium sulfate, 2.0 g of titanium are placed in a Kjeldahl flask with a capacity of 100 cm 3 with a reflux condenser, 40 cm 3 of sulfuric acid diluted 1:3 are added. After dissolution, I add * sulfuric acid, diluted 1:10. up to a volume of 100 cm 3. The solution is stored in an atmosphere of carbon dioxide.

7.5 Taking measurements

A portion of copper weight indicated in table 6, placed in a beaker with a capacity of 400 cm 3 or a conical flask with a capacity of 500 cm 3 , add nitric acid, diluted 1:1. in the amount indicated in table 6. Heated until the sample is dissolved and nitrogen oxides are removed.

Table 6

100 cm 3 of water are added to the resulting solution. 1 cm 3 solution of iron ammonium alum is heated to a temperature of 60 * C to 70 ® C and arsenic and iron hydroxide are precipitated with a solution of sodium carbonate. The solution with the precipitate is brought to a boil and left at a temperature of 40 * C to 50 * C for 20 minutes until the precipitate coagulates.

The precipitate is filtered on a medium density filter and washed 3-4 times with ammonium chloride solution. The precipitate is then dissolved on a filter in 25 cm 3 of hydrochloric acid, diluted 1:1. wash the filter 2-3 times with hot water. 100 cm 3 of water are added to the filtrate, heated to a temperature of 60*C to 70*C, and arsenic and iron hydroxide are again precipitated. The precipitate is filtered through the same filter and washed 3-4 times with hot water.

Dissolve the precipitate on the filter in 25 cm 3 of hydrochloric acid, diluted 1:1. collecting the filtrate in the beaker in which the precipitation was carried out. The filter is washed 3-4 times with hot water and discarded.

Iron and arsenic are reduced in the filtrate by adding dropwise a solution of titanium sulfate or chloride until the solution becomes colorless, and then another 1-2 drops.

The solution is placed in a separating funnel with a capacity of 250 cm 3 , three times the volume of purified hydrochloric acid is added, 30 cm 3 of carbon tetrachloride are added and extracted for 2 minutes. After settling, the organic layer is poured into another separating funnel, and another 15 cm 3 of carbon tetrachloride is added to the first one and the extraction is repeated.

The combined organic extracts are washed with 20 cm 3 of hydrochloric acid with a molar concentration of 9 mol/dm 3 for 20 s, then 15 cm 3 of water are added to the organic layer and arsenic is re-extracted for 2 minutes. Separate the organic layer and repeat the stripping under the same conditions.

the aqueous layers are poured into a mesen flask with a capacity of 50 cm 3, a solution of potassium permanganate is added dropwise until a stable pink color is obtained, which is then destroyed by adding a solution of hydrazine dropwise. Add 4 cm 3 of a freshly prepared hydrazine-molybdenum solution to the flask and place the flask in a boiling water bath for 15 minutes.

The solution was then cooled and made up to the mark with water. Measure the optimal density on a spectrophotometer or photocolorimeter at a wavelength of 610 nm in a cuvette with the optimal layer thickness. Water is used as a reference solution.

The measurements are carried out in accordance with the instructions for use of the spectrophotometer or photocolorimeter, the mass of arsenic in milligrams is set according to the calibration graph.

7.6 Processing measurement results

7.6.1 The mass fraction of arsenic, X.%, is calculated by the formula

where m, is the mass of arsenic found from the calibration curve, mg: t 2 is the mass of arsenic obtained from the results of a blank experiment, mg: m is the weight of the sample of copper. G.

7.6.2 The measurement result is taken as the arithmetic mean of two parallel determinations, provided that the absolute difference between them under repeatability conditions does not exceed the values (at a confidence level P = 0.95) of the repeatability limit r given in Table 5.

If the discrepancy between the largest and smallest results of replicate determinations exceeds the repeatability limit value, follow the procedures described in ISO 5725-6 (Subclause S.2.2.1).

7.6.3 The discrepancies between the measurement results obtained in two laboratories should not exceed the values of the reproducibility limit given in Table 5. In this case, their arithmetic mean value can be taken as the final result. If this condition is not met, the procedures set out in GOST ISO 5725-6 (clause 5.3.3) can be used.

8 Photometric method for measuring the mass fraction of silicon

8.1 Characteristics of measurement accuracy indicators

The measurement accuracy of the silicon mass fraction corresponds to the characteristics given in Table 7 (at P - 0.95;.

The values of the limits of repeatability and reproducibility of measurements at a confidence level P - 0.95 are shown in Table 7.

Table 7 - Values of the indicator of accuracy, limits of repeatability and reproducibility of measurements of the mass dopi of silicon at a confidence level P = 0.95

In percentages

8.2 Measuring instruments, auxiliary devices, materials, solutions

When performing measurements, the following measuring instruments and auxiliary devices are used:

Spectrophotometer or photocolorimeter with all accessories capable of measuring* at a wavelength of 750 to 800 nm;

Electrolysis plant:

pH meter;

Watch glass:

Platinum bowls and crucibles according to GOST 6563:

Laboratory scales of a special accuracy class according to GOST 24104;

Glasses H-1-250TXS according to GOST 25336;

Volumetric flasks 2*50*2.2*100*2.2*1000*2 according to GOST 1770:

Pipettes are not lower than the 2nd accuracy class according to GOST 29169 and GOST 29227.

When performing measurements, the following materials and solutions are used:

Distilled water according to GOST 6709:

High purity nitric acid according to GOST 11125. diluted 2:1.1:1:

Sulfuric acid according to GOST 4204. diluted 1:1:

Water ammonia according to GOST 3760;

Citric acid according to GOST 3652. solution of mass concentration 500 g / dm e;

Ammonium molybdate according to GOST 3765, twice recrystallized: a solution of mass concentration of 100 g / dm 3 containing 25 cm 3 of ammonia in 500 cm 3;

Tin dichloride ps. solution of mass concentration of 10 g / dm 3 in hydrochloric acid diluted * 1: 1;

Sodium carbonate according to GOST 84:

Silicon (IV) oxide according to GOST 9428. calcined at 1000 * C to constant weight:

Universal indicator paper according to (9).

Notes

2 It is allowed to use reagents manufactured according to other regulatory documents, provided that they provide the metrological characteristics of the measurement results given in this standard.

8.3 Measurement method

The method is based on the measurement of optical density at a wavelength of 750 to 800 nm of a colored blue complex of silicon with ammonium malybdate.

8.4 Preparing to take measurements

8.4.1 Preparation of solutions for building a calibration curve

When preparing solution A, a mass concentration of silicon of 0.04 mg / cm 3, a sample of silicon dioxide weighing 0.0856 g is placed in a platinum crucible and fused with 1.0 g of sodium carbonate at a temperature of 900 * C to 1000 * C. The alloy is leached with hot water, cooled, placed in a volumetric flask with a capacity of 1000 cm 3, topped up with water to the mark and mixed.

When preparing solution B, the mass concentration of silicon is 0.004 mg/cm 3 an aliquot of 10 cm 3 of solution A is placed in a measuring tube with a capacity of 100 cm 3 and topped up with water to the mark. The solution is prepared before use, stored in a polyethylene container.

8.4.2 Building a calibration curve

In six volumetric flasks with a capacity of 50 cm 3 each place 0.0; 0.5:1.0:2.0; 5.0 and 10 cm 3 of solution B. which corresponds to OD 0.002; 0.004; 0.008; 0.020 and 0.040 mg silicon. From 15 to 20 cm 3 of water is poured into each flask and neutralized with ammonia or nitric acid to a pH of 1.2 to 1.4 (according to indicator paper or on a pH meter). Zatei pour 2 cm 3 of a solution of citric acid and allow the solutions to stand for another 5 minutes. After that, e flasks are poured with 5 cm 3 of a solution of ammonium molybdate, 0.2 cm 3 of a solution of tin dichloride, topped up with water to the mark and mixed.

According to the obtained values of the optical density and the corresponding silicon concentrations, a calibration graph is built.

8.5 Taking measurements

8.5.1 A weighing of copper weighing 2.0000 g (with a mass fraction of silicon up to 0.002%) or 0.5000 g (with a mass fraction of silicon over 0.002%) is placed in a beaker with a capacity of 250 cm 3, 20 cm 3 of nitric acid diluted 1:1 is added. and 5 cm 3 sulfuric acid, diluted 1:1. cover the beaker with glass and leave without heating until the release of nitrogen oxides stops. The glass is removed, washed with water over the glass, and the solution is heated until the sample is dissolved. Then pour from 150 to 180 cm 3 of water, heat the solution to a temperature of 40 ®C. platinum mesh electrodes are immersed in the solution and electrolysis is carried out for 2-2.5 h at a current density of 2 to 3 A/dm 2 . voltage from 2.2 to 2.5 V with stirring.

When the solution becomes colorless, the electrodes are removed, washed with water, and the electrolyte is evaporated to a volume of 10 to 15 cm 3 . Cool, add water to a volume of 20 cm 3 and neutralize with ammonia or nitric acid diluted 2:1. up to a pH value of 1.2 to 1.4 (according to indicator paper or on a pH meter). 2 cm 3 of citric acid are poured and allowed to stand for 5 minutes. The solution is transferred into a volumetric flask with a capacity of 50 cm 3, 5 cm 3 of a solution of ammonium molybdate is added. 0.2 cm 3 of a solution of stannous chloride, add water to the mark and mix.

Measure the optical density of the solution on a spectrophotometer or photocolorimeter at a wavelength of 750 to 800 nm in a cuvette with the optimal layer thickness. The reference solution is a blank experiment solution.

The measurements are carried out in accordance with the instructions for use of the spectrophotometer or photocolorimeter, the mass of silicon in milligrams is set according to the calibration graph.

8.6 Processing measurement results

8.6.1 Mass fraction of silicon X.%. calculated according to the formula

where m t is the mass of silicon found from the calibration curve, mg t is the weight of the sample of copper. G.

8.6.2 The measurement result is taken as the arithmetic mean of two parallel determinations, provided that the absolute difference between them under repeatability conditions does not exceed the values (at a confidence level P - 0.95) of the repeatability limit r given in Table 7.

8.6.3 The discrepancies between the measurement results obtained in two laboratories should not exceed the values of the reproducibility limit given in Table 7. In this case, their arithmetic mean value can be taken as the final result. If this condition is not met, the procedures set out in GOST ISO 5725-6 (clause 5.3.3) can be used.

9 Extraction-photometric method for measuring the mass fraction

nickel

9.1 Characteristics of measurement accuracy indicators

Accuracy indicators of measurements of the mass fraction of nickel correspond to the characteristics given in table 8 (at Р - 0.95).

The values of the limits of repeatability and reproducibility of measurements at a confidence level P - 0.95 are given in Table 8.

Table 8 - Values of the accuracy index, repeatability limits and reproducibility of measurements of the mass fraction of nickel at a confidence level Р = 0.95

In percentages

Nickel mass fraction measurement range	A languorizer in A	(absolute machenya)
Nickel mass fraction measurement range	A languorizer in A	repeatability g(l *2)	reproducibility
From 0.000 to 0.00020 incl.
St. 0.0002 » 0.0005 x
» 0.0005 » 0.0010 x
» 0.0010 » 0.0020 x
» 0.0020 » 0.0050 >-

9.2 Measuring instruments, auxiliary devices, materials, solutions

When performing measurements, the following measuring instruments and auxiliary devices are used:

Spectrophotometer or photocolorimeter with all accessories capable of measuring at a wavelength of 520 to 540 nm:

Electrolysis plant:

Heating plate according to . providing heating temperature up to 400 *C or similar:

Platinum mesh electrodes according to GOST 6563:

Laboratory scales of a special accuracy class according to GOST 24104;

Volumetric flasks 2-50*2.2-100-2.2-1000-2 according to GOST 1770;

Glasses B-1-100 THS. V-1-400 THS according to GOST 25336;

Conical flasks Kn-2-1000-29/32 THS according to GOST 25336;

Dividing funnels VD-1-50 XC. VD-1-100 XC according to GOST 25336;

Pipettes not lower than the 2nd accuracy class according to GOST 29169 and GOST 29227.

When performing measurements, the following materials and solutions are used:

Nitric acid according to GOST 4461;

Hydrochloric acid according to GOST 3118 and a solution of mass concentration 0.5 mol / dm 3;

Water ammonia according to GOST 3760. diluted 2:98:

Sodium hydroxide according to GOST 4328. solution with a molar concentration of 40 mol / dm 3;

Dimvtylglyoxime according to GOST 5828. solution of mass concentration of 10 g / dm e in ethyl alcohol and the same in sodium hydroxide solution;

Ammonium persulphate according to GOST 20478, solution of mass concentration 100 g/dm 3 ;

Chloroform according to GOST 20015;

Hydroxylamine hydrochloride according to GOST 5456. solution of mass concentration 100 g / dm 3;

Sodium citrate trisubstituted according to GOST 22280. solution of mass concentration 100 g / dm 3;

Triethanolamine by . solution of mass concentration 100 g / dm 3:

Potassium-sodium tartrate according to GOST 5845. solution of mass concentration 100 g / dm 3;

Ammonium chloride according to GOST 3773. solution of mass concentration 60 g / dm 3;

Disodium salt ethylenediamine-N. N. N ". N'-tetraacetic acid. 2-aqueous (trilon B) according to GOST 10652, a solution of a molar concentration of 0.05 mol / dm 3:

Phenolphthalein by . solution of mass concentration 0.10 g/dm 3 in ethyl alcohol;

Hydrogen peroxide according to "OST 10929:

Nickel primary according to GOST 849;

Nickel (I) sulfate according to GOST 4465.

Notes

2 It is allowed to use reagents manufactured according to other regulatory documents, provided that they provide the metrological characteristics of the measurement results given in this standard.

9.3 Measurement method

The method is based on the measurement of the optical density of a colored complex compound of nickel with dimethylglyoxmm at a wavelength of 520 to 540 nm. Copper is pre-separated by electrolysis.

9.4 Preparing to take measurements

9.4.1 Preparation of solutions for building a calibration curve

When preparing solution A, the mass concentration of nickel is 0.1 mg / cm 3, a sample of metallic nickel weighing 0.1000 g is placed * in a conical flask with a capacity of 1000 cm 3, from 5 to 10 cm 3 hydrochloric acid is poured with the addition of 2 - 3 cm 3 hydrogen peroxide. After dissolving the sample, the solution is cooled and poured from 5 to 7 cm 3 of sulfuric acid, diluted 1:1. the solution is evaporated until thick white fumes of sulfuric acid appear. The solution is cooled, poured from 100 to 120 cm 3 of water, heated until the salts dissolve and cooled again. Place the solution in a volumetric flask with a capacity of 1000 cm 3, add water to the mark and mix.

The same solution can be prepared from nickel sulfate: a sample of salt weighing 0.4784 g is placed in a volumetric flask with a capacity of 1000 cm 3, from 100 to 200 cm 3 of water is added. 1 cm 3 sulfuric acid * lot, stir until the sample is dissolved, add water to the mark and mix.

When preparing solution B, mass concentration of nickel is 0.01 mg/cm 3 an aliquot of 10 cm 3 of solution A is placed in a volumetric flask with a capacity of 100 cm 3, 1 cm 3 of sulfuric acid diluted 1:1 is added. Dilute to the mark with water and mix.

When preparing solution C, a mass concentration of nickel of 0.002 mg/cm 3 an aliquot of 10 cm 3 of solution B is placed in a volumetric flask with a capacity of 50 cm 3, 0.5 cm 3 of sulfuric acid diluted 1:1 is added. Dilute to the mark with water and mix.

9.4.2 When preparing a mixture of acids for dissolution, mix 500 cm 3 of sulfuric acid with 1250 cm 3 of water, after cooling, add 350 cm 3 of nitric acid and mix.

9.4.3 Building a calibration curve

8 six volumetric flasks with a capacity of 50 cm 3 each placed 0.0; 1.0; 2.0; 3.0; 4.0 and 6.0 cm 3 of solution 8. which corresponds to 0.0; 0.002 0.004; 0.006; 0.008 and 0.012 mg nickel. Water is poured into each flask to a volume of No. cm 3, then 2 cm 3 of a solution of potassium-sodium tartrate, 1 cm 3 of a solution of sodium hydroxide are sequentially poured. 5 or 3 dimethylglyoxime solution in sodium hydroxide solution and after adding each reagent, mix. After 5-7 minutes, 5 cm 3 of Trilon B solution and 5 cm 3 of ammonium chloride solution are added, topped up with water to the mark and mixed.

The optical density of the solution is measured after 7-10 minutes on a spectrophotometer or photocolorimeter at a wavelength of 520 to 540 nm in a cuvette with the optimal layer thickness. The reference solution is water.

Based on the obtained values of optical density and the corresponding nickel concentrations, a calibration curve is built.

9.5 Taking measurements

9.5.1 A sample of copper weighing 2.0000 g is placed in a beaker with a capacity of 400 cm 3 , from 20 to 25 cm 3 a mixture of acids is added to dissolve and heated until the sample is dissolved and nitrogen oxides are removed. The solution is cooled, poured from 150 to 160 cm 3 of water, mesh platinum electrodes are placed in the glass and electrolysis is carried out at a current strength of 2 to 2.5 A and a voltage of 2 to 2.5 V. At the end of the electrolysis, the electrodes are removed from the solution and washed with alcohol (based on 10 cm 3 of alcohol per determination), then with water.

The electrolyte is evaporated when heated to a volume of 50 to 70 cm 3 and after cooling, placed in a volumetric flask with a capacity of 100 cm 3 and topped up to the mark with water.

8 depending on the mass fraction of nickel and copper take an aliquot 5.10. 20 cm3. Place it in a separating funnel with a capacity of 100 cm 3, dilute with water to a volume of 50 cm 3 and pour 1 cm 3 of triethanolamine solution. 5 cm 3 sodium citrate solution. 2 cm 3 solution of hydrochloric acid hydroxylamine and mix the solution. Then 2-3 drops of a solution of phenolphthalein are added and neutralized with ammonia until a pink color appears, and then another 2-3 drops of ammonia.

10 cm 3 of an alcohol solution of dimvtylglyoxime are poured into a separating funnel. after 2-3 minutes, 10 cm 3 of chloroform and extracted for 1 minute. The organic layer is poured into another separating funnel with a capacity of 50 cm 3 and another 5 cm 3 of chloroform is added to the aqueous layer and the extraction is repeated. The extract is added to the first portion and the aqueous layer is discarded.

To the combined extras there is added 15 cm 3 of ammonia diluted 2:98. and extracted for 1 min. Discard the aqueous layer, add 15 cm 3 of ammonia solution to the organic layer and repeat the extraction. The aqueous layer is discarded again.

To extract nickel from the chloroform extract, 15 cm 3 of a hydrochloric acid solution with a molar concentration of 0.5 mol/dm 3 is poured into a separating funnel and shaken vigorously for 1 min. The organic layer is poured into another separating funnel with a capacity of 50 cm 3 and stripping is repeated with 15 cm 3 hydrochloric acid solution with a molar concentration of 0.5 mol/dm 3 . The organic layer is discarded, and the hydrochloric acid layer is poured into a beaker with a capacity of 100 cm 3 and evaporated to dry salts.

From 1 to 2 cm 3 of a mixture of nitric and hydrochloric acids (1:3) is poured into the dry residue and again evaporated to thick salts. Then add 1 cm 3 hydrochloric acid and evaporate to dryness. From 0.5 to 1 cm 3 of hydrochloric acid with a molar concentration of 0.5 mol / dm 3 is added to the dry residue, from 8 to 10 cm 3 of water is poured and the solution is transferred into a volumetric flask with a capacity of 50 cm 3.

They stick to the solution in the flask sequentially, stirring after adding each reagent. 2 cm 3 solution of potassium-sodium tartrate. 5 cm 3 of ammonium sulfate solution and then continue the measurement as described in 9.4.3.

The measurements are carried out in accordance with the instructions for use of the spectrophotometer or photocolorimeter, the mass of nickel in milligrams is set according to the calibration graph.

9.6 Processing measurement results

9.6.1 Mass fraction of nickel X, %. calculated according to the formula

where mi is the nickel mass found from the calibration curve, mg; m2 is the mass of nickel obtained from the results of a blank experiment, mg; t is the weight of the sample of copper. G.

9.6.2 The result of the changes is taken as the arithmetic mean of two parallel determinations, provided that the absolute difference between them under repeatability conditions does not exceed the values (at a confidence level P - 0.95) of the repeatability limit r given in Table 8.

If the discrepancy between the largest and smallest results of parallel determinations exceeds the value of the repeatability limit, the procedures described in GOST ISO 5725 * 6 (subclause 5.2.2.1) are performed.

9.6.3 The discrepancies between the measurement results obtained in two laboratories should not exceed the values of the reproducibility limit given in Table 8. In this case, their arithmetic mean value can be taken as the final result. If this condition is not met, the procedures set forth in GOST ISO 5725 * 6 (clause 5.3.3) can be used.

10 Spectrophotometric method for measuring the mass fraction of selenium

10.1 Characteristics of measurement accuracy indicators

The accuracy indicators of measurements of the mass fraction of selenium correspond to the characteristics given in table 9 (at P - 0.95)

The values of the limits of repeatability and reproducibility of measurements at a confidence level P = 0.95 are given in Table 9.

Table 9 - Exact gi values. limits of repeatability and reproducibility of measurements of the mass fraction of selenium at a confidence level P = 0.95

In percentages

Selenium mass fraction measurement range	Accuracy index i D	(absolute values)
Selenium mass fraction measurement range	Accuracy index i D	loyalty	reproducibility
From 0.00010 to 0.00020 inclusive
St. 0.0002 a 0.0005 »
» 0.0005 » 0.0010 a
> 0.0010 » 0.0020 a
» 0.0020 » 0.0040 »
» 0.0040 » 0.0100 »

10.2 Measuring instruments, auxiliary devices, materials, solutions

When performing measurements, the following measuring instruments and auxiliary devices are used:

Spectrophotometer or photocolorimeter with all accessories, providing measurements at a wavelength of 335 nm;

Heating plate according to "1]. providing a heating temperature up to 400 * C. or similar;

water bath;

Watch glass;

Laboratory scales of a special accuracy class according to GSST 24104;

Volumetric flasks 2-100-2.2-500*2 according to GOST 1770;

Flasks conical Kn-2-100 THS. Kn-2-250 THS according to GOST 25336;

Dividing funnels VD-M00 XC according to GOST 25336;

Burettes M-2-25-0.05 according to GOST 29251;

Glasses B-1-100 THS. V-1-250 THS according to GOST 25336;

Pipettes not lower than the 2nd accuracy class according to GOST 29169 and GOST 29227.

11 When performing measurements, the following materials and solutions are used:

Distilled water according to GOST 6709;

Sulfuric acid according to GOST 4204. diluted 1:1;

Nitric acid according to GOST 4461, diluted 1:1;

Hydrochloric acid according to GOST3118;

Water ammonia according to GOST 3760:

Orthophosphoric acid according to GOST 6552:

Formic acid according to GOST 5648:

Disodium salt these land iamine-N. N. N ". N"-tetraacetic acid 2-eone (trilon B) according to GOST 10652, a solution of a molar concentration of 0.1 mol / dm 3;

Benzene according to GOST 5955;

Toluene according to GOST 5789;

Opmo-phenylenediamine hydrochloric acid by . solution of mass concentration of 10 g / dm 3 (use freshly prepared). It is allowed to use a qualification reagent below analytical grade;

Technical selenium according to GOST 10298:

Notes

2 It is allowed to use reagents manufactured according to other regulatory documents, provided that they provide the metrological characteristics of the measurement results given in this standard.

10.3 Measurement method

The method is based on measuring the optical density of a complex compound of selenium with an ortho-phenylenediamine. extractable with benzene or toluene. The interfering influence of copper is eliminated by adding an excess of the reagent, iron - by phosphoric acid, bismuth - by Trilon B.

10.4 Preparing to take measurements

10.4.1 Preparation of solutions for building a calibration curve

When preparing solution A, a selenium mass concentration of 0.1 mg / cm 3, a sample of selenium weighing 0.0500 g is placed in a beaker with a capacity of 100 cm 3, from 7 to 10 cm 3 of nitric acid is poured, selenium is dissolved by heating in a water bath, 10 cm 3 of hydrochloric acid are poured. From 15 to 20 cm 3 of water is poured into the solution, cooled and transferred to a volumetric flask with a capacity of 500 cm 3, from 15 to 20 cm 3 of hydrochloric acid is added, topped up with water to the mark and mixed.

When preparing solution B, the mass concentration of selenium is 0.001 mg/cm3, an aliquot of 5 cm3 of solution A is placed in a volumetric flask with a capacity of 500 cm3, 5 cm3 of hydrochloric acid is added, topped up with water to the mark, and mixed.

10.4.2 Building a calibration curve

In nine conical cogs with a capacity of 100 cm 3 each place 0.0: 0.5: 1.0: 2.0; 3.0:5.0; 7.0: 10.0 and 15.0 cm 3 of solution B. which corresponds to 0; 0.0005: 0.0010; 0.0020; 0.0030; 0.0050; 0.0070; 0.0100 and 0.0150 mg selenium. The solutions are diluted with water to a volume of 30 to 35 cm 3 , 1 cm 3 of formic acid is added. 5 cm 3 orthophosphoric acid. 0.5 cm 3 of a solution of Trilon B and then ammonia dropwise to pH 1 (according to universal indicator paper). After that, 3 cm 3 of a solution of ortho-phenylenediamine is poured and left for 20-25 minutes

The resulting solution is placed in a separating funnel with a capacity of 100 cm 3 , 5 cm 3 of benzene or tolusle are poured from the burette and extracted for 2 minutes. The extract is poured into a dry beaker and its optical density is measured on a spectrophotometer at a wavelength of 335 nm in a cuvette with a layer thickness of 10 mm.

The reference solution is benzene (toluene).

Based on the obtained values of optical densities and the corresponding selenium concentrations, a calibration curve is built.

10.5 Taking measurements

Two weights of copper weighing from 1.0000 to 2.0000 g in accordance with table 10 are placed in glasses with a capacity of 250 cm 3 . In one glass enter the additive solution of selenium with a mass concentration of 0.1 mg/cm 3 . the volume of which is chosen so that the analytical signal of the component increased from 2 to 3 times compared to this analytical signal in the absence of additives.

Table 10

From 20 to 25 cm 3 of nitric acid, diluted 1:1, is poured into glasses. and leave without heating for 5-10 minutes. The solution is then heated and evaporated to a volume of 4 to 5 cm 3 . Cool, pour from 10 to 20 cm 3 sulfuric acid, diluted 1:1. and heated until sulfuric acid vapor is released. The solution is cooled, 5 to 10 cm 3 of water are added and evaporated again until acid vapor appears. After cooling, pour from 20 to 40 cm 3 of water, cover the glass with glass and heat to a boil. The solution is cooled and, depending on the sample taken, it is placed in a conical or volumetric flask with a capacity of 100 cm 3. The solution in the volumetric flask is diluted with water to the mark and mixed.

The entire solution or an aliquot of the solution in accordance with table 10 with a volume of 10 to 20 cm 3 is transferred into a 100 cm 3 conical flask, diluted with water so. so that the final volume does not exceed 30-35 cm 3, 1 cm 3 of formic acid is added. 5 cm 3 orthophosphoric acid. 0.5 cm 3 solution of Trilon B. then ammonia dropwise to pH 1. 3 cm 3 opmo-femilenediamine and leave for 20-25 minutes.

Then the solution is poured into a separating funnel, 5 cm 3 of benzene or toluene are poured from the burette and extracted for 2 minutes. The extract is poured into a dry glass and the optical density is measured on a spectrophotometer at a wavelength of 335 nm in a cuvette with a layer thickness of 10 mm. The reference solution is benzene (toluene).

measurements are carried out in accordance with the instructions for use of the spectrophotometer or photocolorimeter, the mass of selenium in milligrams is set according to the calibration graph.

10.6 Processing measurement results

10.6.1 Mass fraction of selenium X%. calculated according to the formula

where m is the mass of selenium found from the calibration curve, mg;

V- volumetric flask capacity, cm 3;

Vi is the volume of an aliquot of the solution, cm3; m is the weight of the sample of copper. G.

10.6.2 The measurement result is taken as the arithmetic mean of two parallel determinations, provided that the absolute difference between them under repeatability conditions does not exceed the values (at a confidence level P - 0.95) of the repeatability limit r given in Table 9.

10.6.3 The discrepancies between the measurement results obtained in two laboratories should not exceed the values of the reproducibility limit given in Table 9. In this case, their arithmetic mean value can be taken as the final result. If this condition is not met, the procedures set out in GOST ISO 5725-6 (clause 5.3.3) can be used.

11 Extraction-photometric method for measuring the mass fraction

antimony

11.1 Characteristics of measurement accuracy indicators

The accuracy of measurements of the mass fraction of antimony correspond to the characteristics given in table 11 (at P - 0.9S).

The values of the limits of repeatability and reproducibility of measurements at a confidence level of P-0.95 are shown in Table 11.

Table 11 - Values of the indicator of accuracy, limits of repeatability and reproducibility of measurements of the mass fraction of antimony at a confidence level Р = 0.95

In percentages

Range of measurement of mass fraction of antimony	ACCURACY index 1 l	(absolute values)
Range of measurement of mass fraction of antimony	ACCURACY index 1 l	repeatability	reproducibility
From 0.0003 to 0.0005 incl.
St. 0.0005 » 0.0010 »
» 0.0010 » 0.0030 »
» 0.003 » 0.010 »

11.2 Measuring instruments, auxiliary devices, materials, solutions

When performing measurements, the following measuring instruments and auxiliary devices are used:

Spectrophotometer or photocolorimeter with all accessories capable of measuring* at a wavelength of 590 nm;

Watch glass:

Laboratory scales of a special accuracy class according to GOST 24104;

Volumetric flasks 2-50-2.2-100-2.2-1000-2 according to GOST 1770;

Glasses B-1-50 THS. V-1-250 THS according to GOST 25336:

Conical flasks Kn-2-250 THS according to GOST 25336;

Funnels for filtering laboratory in accordance with GOST 25336;

Dividing funnels VD-3-100 XC according to GOST 25336:

Pipettes not lower than the 2nd accuracy class according to GOST 29169 and GOST 29227;

Dephlegmator according to GOST 25336.

When performing measurements, the following materials and solutions are used:

Distilled water according to GOST 6709;

Nitric acid according to GOST 4461, diluted 3:97:

Hydrochloric acid according to GOST 3118, diluted 3:1.7:3;

Sulfuric acid according to GOST 4204 and diluted 1:10;

Ammonium nitrate according to GOST 22867, solution of mass concentration 150 g / dm 3:

Brilliant green indicator, water-alcohol solution of mass concentration 5 g/dm 3 ;

Iron powder according to GOST 9849, solution of mass concentration 15 g/dm 3 in hydrochloric acid, diluted 1:10;

Carbamide according to GOST 6691, saturated solution:

Sodium hydroxide according to GOST 4197, solution of mass concentration 100 g / dm 3:

Tin dichloride according to . solution of mass concentration of 100 g/DM 3 in hydrochloric acid, diluted 1:1;

Tin according to GOST 860;

Toluene according to GOST 5789 (heregnane) or benzene according to GOST 5955;

Rectified technical ethyl alcohol according to GOST 18300;

Antimony according to GOST 1089:

Filters are either broken by (3] or dialogical;

Filter paper according to GOST 12026.

Notes

2 It is allowed to use reagents manufactured according to other regulatory documents, provided that they provide the metrological characteristics of the measurement results given in this standard.

11.3 Measurement method

The method is based on the measurement of optical density at a wavelength of 590 nm of a colored antimony (V) chloride complex with brilliant green after antimony is separated by co-precipitation with metastannic acid, antimony (III) is oxidized with sodium hydroxide, and the complex is extracted with toluene (benzene).

11.4 Preparing to take measurements

11.4.1 Preparation of solutions for building a calibration curve

When preparing rasteor A, a mass concentration of antimony of 0.1 mg / cm 3, a sample of antimony weighing 0.1000 g is placed in a conical flask with a capacity of 250 cm 3, 20 cm 3 of sulfuric acid diluted 1:10 is added, and heated until the sample is dissolved. After cooling, the solution is placed in a volumetric flask with a capacity of 1000 cm 3 equipped with a reflux condenser. Pour 200 cm 3 hydrochloric acid, diluted 7:3, and heat until the sample dissolves. After cooling, the solution is evaporated to a volume of 5 to 10 cm 3 , placed in a 1000 cm 3 pulp flask and topped up to the mark with sulfuric acid diluted 1:10.

When preparing solution B, the mass concentration of antimony is 0.01 mg/cm 3 an aliquot of 10 cm 3 of solution A is placed in a volumetric flask with a capacity of 100 cm 3 and topped up to the mark with sulfuric acid diluted 1:10. The solution is used freshly prepared.

When preparing solution B, the mass concentration of antimony is 0.002 mg/cm 3 an aliquot of 20 cm 3 of solution A is placed in a volumetric flask with a capacity of 100 cm 3 and topped up to the mark with sulfuric acid diluted 1:10. The solution is used freshly prepared.

11.4.2 When preparing an aqueous-alcoholic solution of a brilliant green indicator with a mass concentration of 5 g / dm 3, 0.5 g of the indicator is dissolved in 100 cm 3 of a mixture of alcohol and water in a ratio of 1:3.

11.4.3 When preparing a saturated solution of carbamide, dissolve 50 g of urea in 50 cm 3 of water with heating, then filter the solution.

The solution is used freshly prepared.

11.4.4 Building a calibration curve

8 seven glasses of eight with a capacity of 50 cm 3 each place 1.0.2.0: 3.0: 4.0 and 5.0 cm 3 of solution 8 and 2.0 and 3.0 cm 3 of solution B. which corresponds to 0.002: 0.004; 0.006; 0.008; 0.010; 0.020; 0.030 mg antimony. The solutions are evaporated to wet salts, cooled, 10 cm 3 of hydrochloric acid diluted 3:1 are added, heated until the salts dissolve, three drops of ferric chloride solution are added, and tin dichloride solution is added until the iron is reduced. 1 cm 3 solution of sodium nitrite and leave for 5 minutes. Wash the walls of the glass with water and pour 1 cm 3 of a solution of carbamide. Transfer the solutions to separating funnels with a capacity of 100 cm 3, add water to a volume of 75 cm 3. pour from 1 to 2 cm 3 of brilliant green solution. 10 cm 3 of toluene or Benesl and extracted for 1 minute. The toluene (benzene) layer is separated and, after 15-20 minutes, the ottic density of the extract is measured on a spectrophotometer or photocolorimeter at a wavelength of 590 nm in a cuvette with a layer thickness of 10 mm. The reference solution is toluene (benzene).

Based on the obtained values of optical densities and the corresponding antimony concentrations, a calibration curve is built.

11.5 taking measurements

A sample of copper weighing 2.0000 g is placed in a beaker (conical flask) with a capacity of 250 cm 3, from 0.01 to 0.02 g of tin is added, from 20 to 25 cm 3 of nitric acid is added, the beaker or flask is covered with glass and heated until the sample is dissolved. The glass is removed, washed with water over a glass (flask) and the solution is evaporated to a volume of 5 to 7 cm 3. Then, from 100 to 120 cm 3 of hot water, from 20 to 25 cm 3 of ammonium nitrate solution are added, a little filter paper mass is added and boiled from 10 to 20 min. Leave the solution with the precipitate in a warm place on the stove for 2 to 2.5 hours.

After that, the solution is filtered through a filter, in the cone of which a little filter paper mass is embedded. The cola and the filter are washed 10 to 1b times with hot nitric acid diluted 3:9/.

The filter with the precipitate is placed in a beaker or flask in which precipitation was carried out, 20 cm 3 of nitric acid and 10 cm 3 of sulfuric acid diluted 1:10 are added. cover with a cover slip and heat until nitrogen oxides are removed. The glass is removed, washed with water over a beaker (flask) and the solution is evaporated until the appearance of dry vapors of sulfuric acid. If the solution darkens at this point, ammonium nitrate is added until the solution becomes colorless.

Cool, place the solution in a volumetric flask with a capacity of 50 cm 3, add to the mark with sulfuric acid diluted 1:10. and mix.

A 25 cm 3 aliquot is taken and placed in a 50 cm 3 beaker. Evaporated by heating to wet salts, poured 10 cm 3 hydrochloric acid, diluted 3:1. and heated until the salts dissolve. Then continue, as indicated in 11.4.4.

The measurements are carried out in accordance with the instructions for use of the spectrophotometer or photocolorimeter, the mass of antimony in milligrams is set according to the calibration graph.

11.6 Processing measurement results

11.6.1 The mass fraction of antimony, X. %, is calculated by the formula

/l,U100

where m is the mass of antimony found from the calibration curve, mg; Y - volumetric flask capacity, cm 3; m is the weight of the sample of copper, g V\ is the volume of the solution aliquot, cm 3 .

11.6.2 The arithmetic mean of two parallel determinations is taken as the measurement result, provided that the absolute difference between them under repeatability conditions does not exceed the values (at a confidence level P = 0.95) of the repeatability limit /; given in table 11.

11.6.3 The discrepancies between the measurement results obtained in two laboratories should not exceed the values of the reproducibility limit given in Table 11. In this case, their arithmetic mean value can be taken as the final result. If this condition is not met, the procedures set out in GOST ISO 5725-6 (clause 5.3.3) can be used.

12 Extraction-photometric method for measuring the mass fraction of phosphorus

12.1 Characteristics of measurement accuracy indicators

Measurement accuracy indicators of the mass fraction of phosphorus correspond to the characteristics given in table 12 (at P - 0.95).

The values of the limits of repeatability and reproducibility of measurements at a confidence level P = 0.95 are given in Table 12.

Table 12 - Values of the accuracy index, repeatability limits and reproducible gi measurements of the mass fraction of phosphorus at a confidence level P = 0.95

In percentages

Mass fraction measurement range of phosphorus	Index PRECISION 1 l	(absolute values)
Mass fraction measurement range of phosphorus	Index PRECISION 1 l	repeatability r(i*2)	OOS pro I 3 04DI S OS t I R
From 0.00010 to 0.00030 inclusive
St. 0.0003 » 0.0006 »
» 0.0006 » 0.0012 »
0.0012 0.0030 »
» 0.003 » 0.006 »

12.2 Measuring instruments, auxiliary devices, materials, solutions

When performing measurements, the following measuring instruments and auxiliary devices are used:

Spectrophotometer or photocolorimeter with all accessories capable of measuring at a wavelength of 620 to 630 nm or 720 nm:

Heating plate according to . providing heating temperature up to 400 *C. or similar:

Laboratory scales of a special accuracy class according to GOST 24104;

Glasses V-1-100 THS or N-1-100 THS, V-1-250 THS according to GOST 25336:

Volumetric flasks 2-25-2.2-100-2.2*1000-2 according to GOST 1770:

Dividing funnels VD-1-SOXC. VD-1-100 XS. VD-1-150 XS according to GOST 25336;

Pipettes not lower than the 2nd accuracy class according to GOST 29169 and GOST 29227;

Cups made of glassy carbon according to .

When performing measurements, the following materials and solutions are used:

Distilled water according to GOST 6709;

Nitric acid according to GOST 4461 or high purity nitric acid according to GOST 11125, diluted 2:1:

Hydrochloric acid according to GOST 3118 and diluted 1:9;

Sulfuric acid according to GOST 4204. solution with a molar concentration of 0.5 mol / dm 3;

Glycerin according to GOST 6259:

Tin dichloride according to a solution of a mass concentration of 100 g / dm 3 in glycerin, a solution of a mass concentration of 40 g / dm 3 in hydrochloric acid, diluted 1:9;

Potassium permanganate then GOST 20490. solution of mass concentration 50 g / dm 3:

Butanol-1 according to GOST € 006, distilled at a temperature of 118 * C;

Chloroform according to GOST 20015, distilled;

Extraction mixture: 30 cm 3 of butanol-1 are mixed with 70 cm 3 of chloroform:

Copper according to GOST 859;

Sodium phosphate disubstituted according to GOST 11773. dried to constant weight at a temperature of 102 ° C to 105 ° C;

Potassium phosphate monohydrate according to GOST 4198. dried to constant weight at a temperature of 102 * C to 105 * C:

Water ammonia according to GOST 3760;

Ammonium molybdenum oxide according to GOST 3765 (recrystallized). solution of mass concentration * concentration 100 g / dm 3;

Recovery mixture;

Universal indicator paper according to .

Notes

2 It is allowed to use reagents manufactured according to other regulatory documents, provided that they provide the metrological characteristics of the measurement results given in this standard.

12.3 Measurement method

The method is based on the measurement of optical density at a wavelength of 620 to 630 nm or 720 nm of a colored complex compound of molybdophosphoric heterolopic acid after selective extraction with a mixture of butanol and chloroform.

12.4 Preparing to take measurements

12.4.1 Preparation of solutions for building a calibration curve

When preparing solution A, the mass concentration of phosphorus is 0.1 mg / cm 3, a sample of disubstituted * sodium phosphate weighing 0.4580 g or monosubstituted potassium phosphate weighing 0.4393 g is placed in a volumetric flask with a capacity of 1000 cm 3, from 100 to 150 cm 3 of water are added, Dilute to the mark with water and mix.

When preparing solution B, the mass concentration of phosphorus is 0.01 mg/cm3, an aliquot of 10 cm3 of solution A is placed in a 100 cm3 measuring cup, topped up with water to the mark, and mixed. The solution is prepared on the day of measurements.

12.4.2 When preparing the reducing mixture, mix 50 cm 3 of a freshly prepared solution of stannous chloride in hydrochloric acid and 450 cm 3 of sulfuric acid with a molar concentration of 0.5 mol/dm 3 . Prepare before use.

12.4.3 Building a calibration curve

In seven dividing voromsks with a capacity of 50 cm 3 each place 0.0; 0.10; 0.20; 0.50:1.00; 1.5 and 2.0 cm 3 of solution B. which corresponds to 0.0; 0.001:0.002; 0.005; 0.010; 0.015 and 0.020 mg of phosphorus.

8 Each funnel is poured with about 3 cm 3 of hydrochloric acid, 7 cm 3 of water, 5 cm 3 of ammonium molybdate* solution, and then extraction is carried out as described in 12.5.1.

Based on the obtained values of optical densities and their corresponding phosphorus concentrations, a calibration graph is built.

12.5 Taking measurements

12.5.1 Two 1.0000 g copper samples are placed in glassy carbon cups or beakers (conical flasks) with a capacity of “00 cm 3 . An additive of a solution of phosphorus with a phosphorus mass concentration of 0.1 mg/cm 3 is introduced into one cup or glass, the volume of which is chosen so that the analytical signal of the component increases from 2 to 3 times compared with this analytical signal in the absence of the additive. Pour from 0.1 to 0.3 cm 3 of a solution of potassium permanganate and 10 cm 3 of nitric acid. diluted 2:1. Heat until the sample is dissolved and then evaporate to dry salts. The residue is dissolved in 3 cm 3 of hydrochloric acid and 7 cm 3 of water. 5 cm 3 of a solution of ammonium molybdate are added to the resulting solution and incubated for 5 to 7 minutes.

Then transfer to a separating funnel with a capacity of 100 to 150 cm 3 , add 20 cm 3 of the mixture for extraction and extract * for 2 minutes. After separation of the layers, the organic phase is placed in a volumetric flask with a capacity of 25 cm 3 , one drop of tin dichloride solution is added, the extraction mixture is added to the mark and mixed.

Measure the optical density of the extract on a spectrophotometer or photocolorimeter at a wavelength of 620 to 630 nm in a cuvette with a layer thickness of 50 or 30 mm. The reference solution is the extraction mixture.

The measurements are carried out in accordance with the instructions for use of the spectrophotometer or photocolorimeter, the mass of phosphorus in milligrams is set according to the calibration graph.

12.5.2 A 1.0000 g sample of copper is placed in a beaker (conical flask) with a capacity of 250 cm 3 . pour from 0.1 to 0.3 cm 3 potassium permanganate and 20 cm 3 of a mixture of acids for dissolution. Heat until the sample dissolves. Cool, pour from 20 to 30 cm 3 of water, mix. Place in a separating funnel with a capacity of 100 to 150 cm 3, dilute with water to a volume of 50 cm 3, neutralize with ammonia solution to pH ~ 5 (according to universal indicator paper), add 4 cm 3 of boiled nitric acid, 5 cm 3 of ammonium molybdate solution, mix and hold for 10 min.

Then 10 cm 3 of the extraction mixture are added and the mixture is extracted for 2 minutes. After separation of the liquids, the organic layer is poured into another separating funnel with a capacity of 100 cm 3 and 10 cm 3 of the extraction mixture is added to the aqueous layer and the extraction is repeated. The organic layer is poured into the separating funnel containing the first extract, and the aqueous layer is discarded.

Add 20 cm3 of the reductant mixture to the combined extracts and shake vigorously for 1 min. After separation, the aqueous layer is placed in a volumetric flask with a capacity of 25 cm 3 and topped up with water to the mark. The organic layer is discarded.

After 5 minutes, the optical density of the solution is measured on a spectrophotometer at a wavelength of 720 nm in a cuvette with a layer thickness of 10 mm. The reference solution is a blank experiment solution.

The measurements are carried out in accordance with the instructions for use of the spectrophotometer or photocolorimeter. the mass of phosphorus in milligrams is set according to the calibration curve.

12.6 Processing measurement results

12.6.1 Mass fraction of phosphorus X.%. calculated according to the formula

where m is the mass of phosphorus found from the calibration curve, mg; t is the weight of the sample of copper, g.

12.6.2 The measurement result is taken as the arithmetic mean of two parallel determinations, provided that the absolute difference between them under repeatability conditions does not exceed the values (at a confidence level P - 0.95) of the repeatability limit r given in Table 12.

12.6.3 The discrepancies between the measurement results obtained in two laboratories should not exceed the values of the reproducibility limit given in Table 12. In this case, their arithmetic mean value can be taken as the final result. If this condition is not met, the procedures set out in GOST ISO 5725-6 (clause 5.3.3) can be used.

13 The mass fraction of impurities in copper is determined in parallel in two portions. Simultaneously with measurements under the same conditions, a control experiment is carried out to make an appropriate correction to the measurement results. When determining impurities in copper, the number of parallel determinations in the control experiment must correspond to the number of parallel determinations specified in the measurement method.

	Bibliography
(1] Specifications TU 4389-001-44330709-2008 (2] Pharmacopoeia article FS 42-2668-95	Built-in glass-ceramic heating stove LOIP LH-304 Pharmacopoeial ascorbic acid
(3] Specifications TU 264221-001-05015242-07 1 "	De-aerated filters (white, red, blue ribbons)
(4] Specifications TU 6-09-364-83	Potassium iodate mega, pure for analysis. CHDA
(5] Specifications TU 6-09-07-1689-89	1-nigroso-2-nafgoal. Specifications
Specifications TU 6-09-5359-87	Iron ammonium alum. CHDA
(7] Specifications TU 6-09-01-756-86	Titanium trichloride
Specifications TU 6-09-5393-88	Tin dichloride
(9] Specifications TU 6-09-1181-89 (10] Specifications TU 2423-61-05807977-2002	Universal indicator paper for determining pH 1-10 and 7-14 Triethanolamine
(11] Specifications TU 6-09-5360-88	Phenolphthalein
(12] Specifications TU 6-09-05-0512-91	Ortho-phenylvindiamine
(13] Specifications TU 6-09-01-4278-88	Brilliant green, indicator. CHDA
(14] Specifications TU 48-20-117-92	Laboratory glassware made of glassy carbon grade SU-2000

U Valid only on the territory of the Russian Federation.

UDC 669.3.001.4:006.354 MKS 77.120.30

Key words: high purity copper, photometric measurement method, component, measurement range. accuracy indicator, extraction, separating funnels, spectrophotometer

Editor L.I. Nakhimova Technical editor V.N. Prusakova Proofreader Yu.M. Prokofieva Computer layout K.L. Chubanova

Handed over to the set of 04/04/2018. Signed and stamped 13.04.2010. SO"Sd"/g format. Ariel headset.

Uel. to lay down. l. 3.73. Uch.-im-l. 3.40. Circulation 34 em Zach. 1094.

Imano and printed in FSUE STANDARTINFORM. 12399S Moscow. Pomegranate por.. 4.

The Russian Federation has GOST R ISO 5725-6-2002 “Accuracy (correctness and precision) of measurement methods and results. Part 6. Using precision values in practice.

21 8 of the Russian Federation GOST R 55878-2013 “Technical hydrolytic rectified ethyl alcohol. Specifications".

* In the Russian Federation, GOST R 53228-2008 “Scales of non-automatic action. Part 1. Metrological and technical requirements. Tests".

GOST 27981.2-88

Group B59

STATE STANDARD OF THE UNION OF THE SSR

HIGH PURITY COPPER

Method of chemical-atomic-emission analysis

Copper of high purity. Method of chemical-atomic-emission analysis

OKSTU 1709

Valid from 01.01.1990
until 01.01.2000*
_______________________________
* Expiry date removed
according to protocol N 7-95 of the Interstate Council
for standardization, metrology and certification
(IUS N 11, 1995). - Database manufacturer's note.

INFORMATION DATA

1. DEVELOPED AND INTRODUCED by the Ministry of Nonferrous Metallurgy of the USSR

PERFORMERS:

A.M.Kopanev, E.N.Gilbert, L.N.Shabanova, I.D.Denisova, G.L.Buchbinder, B.M.Rogov, E.N.Gadzalov, I.I.Lebed

2. APPROVED AND INTRODUCED BY Decree of the USSR State Committee for Standards dated 22.12.88 N 4443

3. The term of the first check is 1994.

Inspection frequency - 5 years

4. INTRODUCED FOR THE FIRST TIME

5. REFERENCE REGULATIONS AND TECHNICAL DOCUMENTS

	Partition number






GOST 1467-77
GOST 1770-74
GOST 2603-79
GOST 3640-79
GOST 3773-72
GOST 4160-74
GOST 4233-77
GOST 4332-76
GOST 5905-79
GOST 6008-82
GOST 6563-75
GOST 6709-72
GOST 9428-73
GOST 10928-75
GOST 11125-84
GOST 14261-77
GOST 18300-87
GOST 19627-74
GOST 20292-74
GOST 23463-79
GOST 24104-88
GOST 24363-80
GOST 25086-87
GOST 25336-82
GOST 25664-83
GOST 27981.0-88
GOST 27981.1-88

This International Standard establishes a chemical atomic emission method for the determination of impurities in high purity copper in the mass fraction range 10%:

The method consists in dissolving a sample of copper in a mixture of hydrochloric acid and hydrogen peroxide, separating copper from impurities by extraction di-2-ethylhexyldithiophosphoric acid, obtaining a concentrate of impurities on graphite powder with a carrier - sodium chloride and analyzing the concentrate by atomic emission method in a DC arc with photographic registration of the spectrum.

1. GENERAL REQUIREMENTS

1.1. General requirements for the method of analysis and safety requirements when performing analyzes in accordance with GOST 27981.0.

1.2. The mass fraction of impurities in high-purity copper is determined in parallel in three portions.

2. APPARATUS, REAGENTS AND SOLUTIONS

Quartz medium dispersion spectrograph of the ISP-30 type with a three-lens illumination system or a spectrograph of the STE-1 type.

DC power supply for the arc, providing a voltage of 200-400 V and a current of up to 12 A.

Spectroprojector.

Microphotometer.

An electromechanical shaker or apparatus for mixing liquids, for example, type AVB-4P.

Electric hob.

A muffle electric furnace with a thermostat providing a heating temperature of 900-950 °C.

Analytical laboratory scales of any type of the 2nd accuracy class with a weighing error in accordance with GOST 24104*.
_______________
* On the territory of the Russian Federation, GOST 24104-2001 applies. - Database manufacturer's note

Technical scales of any type with a weighing error according to the attached passport.

Torsion scales of any type with a weighing error according to the attached passport.

Machine for sharpening graphite electrodes.

Organic glass box type 8BP-1-OS for sample preparation for spectral analysis (or other type).

Organic glass box type 2BP2-OS for chemical preparation of samples with air (or other type) purified through Petryanov's cloth.

Acquisitions made of organic glass for preparing samples for spectral analysis (supports for graphite electrodes, spatulas, stuffing boxes, etc.).

Platinum bowls according to GOST 6563.

Cover glasses.

Organic glass mortar and pestle, or agate mortar, or porcelain mortars.

Fluoroplastic glasses with screw-on or ground-in lids with a capacity of 20-25 cm.

Evaporating bowls made of quartz, or fluoroplastic, or porcelain, with a capacity of 25 and 100 cm3.

Graphite electrodes, machined from graphite rods OSCH-7-3 with a diameter of 6 mm, sharpened into a cone with an angle at the top of 15 ° and with a platform with a diameter of 1.5 mm at the end.

Graphite electrodes 6 mm in diameter with a channel 3 mm deep and 4 mm in diameter, machined from OSCh-7-3 graphite rods.

Graphite powder according to GOST 23463 grade OSCh-7-3.

Graphite powder obtained by grinding spectrally pure graphite electrodes.

The lamp is infrared.

Photographic plates type 1 and type 2, providing normal blackening of analytical lines and nearby background in the spectrum.

Glasses H-1-100 THS according to GOST 25336.

Glasses V-1-1000 THS according to GOST 25336.

Conical flasks Kn-2-2000 THS according to GOST 25336.

Separating funnel VD-1-100 XC according to GOST 25336.

Separating funnel VD-3-2000 XC according to GOST 25336.

Beakers with a capacity of 50 and 1000 cm3 according to GOST 1770.

Volumetric flasks 2-100-2, 2-200-2 according to GOST 1770.

Pipettes 4-2-1, 4-2-2, 5-2-2, 6-2-5, 6-2-10 according to GOST 20292*.
________________
* GOST 29169-91, GOST 29227-91-GOST 29229-91, GOST 29251-91-GOST 29253-91 are valid on the territory of the Russian Federation. - Database manufacturer's note.

Developer:

metol (4-methylaminophenol sulfate) according to GOST 25664
sodium sulphate according to GOST 195
hydroquinone (paradioxybenzene) according to GOST 19627
sodium carbonate according to GOST 83
potassium bromide according to GOST 4160
	up to 1000 cm
The use of contrast developers of a different composition is allowed.

sodium thiosulfate crystalline according to GOST 244
ammonium chloride according to GOST 3773
distilled water according to GOST 6709	up to 1000 cm

Use of fixing solutions of other structure is allowed.

Acetone according to GOST 2603.

Nitric acid of special purity according to GOST 11125, diluted 1:1.

Hydrochloric acid of special purity according to GOST 14261, diluted 1:1, 1:2.5; 1:10.

High purity hydrogen peroxide (stabilized product).

Sodium chloride according to GOST 4233, solution 40 g/dm.

Potassium carbonate - sodium carbonate according to GOST 4332.

Potassium hydroxide according to GOST 24363.

Acid di-2-ethylhexyldithiophosphoric ( di-2-EGDTFK), purified.

Rectified technical ethyl alcohol according to GOST 18300.

Iron obtained by the carbonyl method, OSCh-6-2.

Bismuth according to GOST 10928* brand Vi00.
______________
* On the territory of the Russian Federation, GOST 10928-90 applies. - Database manufacturer's note.

Cadmium according to GOST 1467* brand Kd0.
______________
* On the territory of the Russian Federation, GOST 1467-93 applies. - Database manufacturer's note.

Cobalt according to GOST 123* brand K0.
______________
* On the territory of the Russian Federation GOST 123-98 is valid (from 07/01/2009 GOST 123-2008 is valid). - Database manufacturer's note.

Silicon dioxide according to GOST 9428.

Manganese according to GOST 6008* brand Mr 00 or Mr 0.
______________
* On the territory of the Russian Federation, GOST 6008-90 applies. - Database manufacturer's note.

Copper according to GOST 859* brand M0k.
______________
* On the territory of the Russian Federation, GOST 859-2001 applies. - Database manufacturer's note.

Chrome in accordance with GOST 5905* brand X00.
______________
* On the territory of the Russian Federation, GOST 5905-2004 applies. - Database manufacturer's note.

Nickel according to GOST 849* grade H0.
______________
* On the territory of the Russian Federation, GOST 849-97 is valid (from 07/01/2009 GOST 849-2008 is valid). - Database manufacturer's note.

Zinc according to GOST 3640* grade Ts0.
______________
* On the territory of the Russian Federation, GOST 3640-94 applies. - Database manufacturer's note.

Standard samples of copper composition.

3. PREPARATION FOR ANALYSIS

3.1. Preparation of standard solutions of elements according to clause 2.2.1 of GOST 27981.1.

3.2. Preparation of multi-element standard solutions

3.2.1. Preparation of solution 1

In a volumetric flask with a capacity of 100 ml, add 15 ml of hydrochloric acid, 2 ml of standard solutions A of cadmium, cobalt and chromium, bring to the mark with water.

1 cm3 of solution 1 contains 20 µg of cadmium, cobalt, chromium.

3.2.2. Preparation of solution 2

In a volumetric flask with a capacity of 100 ml, add 15 ml of hydrochloric acid, 5 ml of solution 1 and bring to the mark with water.

1 cm3 of solution 2 contains 1 µg of cadmium, cobalt, chromium.

3.2.3. Preparation and certification of the synthetic mixture according to clause 2.2.3 of GOST*
______________

3.3. Preparation of reference samples based on graphite powder with a mass fraction of sodium chloride of 4%

3.3.1. Preparation of graphite powder containing 4% sodium chloride

9.600 g of graphite powder is placed in a fluoroplastic (or other material) bowl with a capacity of 100 cm 3, 10 cm 3 of sodium chloride solution are poured in and the mixture is dried first on a tile and then under an infrared lamp. The resulting mixture is stirred in a mortar for 1.5 hours. The mixture is stored in a tightly closed fluoroplastic (or other material) beaker.

3.3.2. Preparation of the main reference sample (CRM)

The main reference sample is prepared with a mass fraction of each of the impurity to be determined of 0.1%: 9.880 g of graphite powder is placed in a fluoroplastic (or other material) bowl with a capacity of 100 cm3 and 10 cm3 of standard solutions A of iron, cadmium, cobalt, bismuth are poured sequentially , nickel, tin, manganese, chromium, zinc and 20 ml of silicon standard solution. Evaporation of impurity solutions on graphite powder is performed under an IR lamp. Each subsequent impurity is introduced into well-dried graphite powder. At the end of evaporation, the graphite powder containing impurities introduced in the form of solutions is dried to constant weight and stirred in a bowl and then in a mortar for 1 hour.

3.3.3. Preparation of working reference samples (RS)

Reference samples (OS1-OS9) are prepared by successive dilution of the OC, and then each subsequent OC with graphite powder with a mass fraction of sodium chloride of 4%. Mass fractions of each of the determined impurity in the OS (in percent) and sample for obtaining each OS are given in table.1. These weighed portions are placed in a mortar, carefully ground in the presence of ethyl alcohol for 30 min and dried under an infrared lamp.

Table 1

Sample Comparison	Mass fraction of each determined impurity, %	Sample weight, g
		graphite powder with a mass fraction of sodium chloride 4%	diluted sample (indicated in parentheses)

Comparison samples are stored in tightly closed cups made of fluoroplast or plastic, or other material.

All operations for the preparation of reference samples are carried out in a box made of organic glass, carefully wiping the walls with ethyl alcohol. One determination consumes 10 g of alcohol and 5 cm of coarse calico.

3.4. Technical cleaning di-2-EGDTFK according to clause 2.2.5 of GOST 27981.1.

3.5. Establishing the volume of the solution di-2-EGLTPA* required for stoichiometric extraction
________________
* Corresponds to the original. - Database manufacturer's note.

In a separating funnel with a capacity of 100 ml, 20 ml of a standard solution of copper and 26 ml of a solution of purified di-2-EGDTFK, copper extraction is carried out for 15 min, the raffinate is separated and the copper content is determined in it by any method, for example, atomic absorption in an acetylene-air or propane-butane-air flame. 1 cm of raffinate should contain 0.01-0.08 mg of copper. If the copper content is higher, the extraction is carried out again, changing accordingly (reducing or increasing) the volume of the extractant used.

Establishing the volume of the solution di-2-EGDTFA required for stoichiometric extraction is carried out once for each batch of extractant.

3.6. Sample dissolution

A portion of the analyzed sample of copper weighing 1.000 g is placed in a beaker with a capacity of 100 cm3. To remove surface contaminants, the sample is washed once with hydrochloric acid diluted 1:10 and twice with water. With a measuring cylinder with a capacity of 25 cm3, 12 cm3 of hydrochloric acid is poured into a glass, the glass is covered with glass and 3-5 cm3 of a 30% hydrogen peroxide solution are injected under the glass with a pipette. 2-3 minutes after completion of the reaction, another 3-5 ml of peroxide is added. After complete dissolution of the sample, the glass is placed on a tile, its contents are slowly brought to a boil. After 3-5 minutes, the glass is removed from the stove and cooled.

3.7. Branch of copper

The glass is removed from the beaker and the solution is quantitatively transferred to a separating funnel with a capacity of 100 ml using 5-7 ml of water. Add the hexane solution to the funnel di-2-EGDTFA in the amount specified in clause 3.5. Copper is extracted for 15-20 minutes. The raffinate is separated and transferred back to the beaker. The organic layer is discarded, the funnel is washed with acetone and then with bidistillate. The raffinate is returned to the funnel, 20 ml of hexane are added to it and shaken for 3-5 minutes to remove residual organic substances.

The raffinate is separated and transferred to an evaporation cup with a capacity of 50 cm3. Then 100 mg of graphite powder with a mass fraction of sodium chloride of 4% is added and the solution is carefully evaporated under an infrared lamp at a temperature of 80-100 ° C.

The resulting dry residue is a concentrate of impurities subjected to analysis.

3.8. Carrying out a control experiment

In a glass with a capacity of 100 ml, 12 ml of hydrochloric acid and 12 ml of a 30% hydrogen peroxide solution are introduced with a measuring cylinder. The solution is heated on a hot plate until the peroxide is decomposed and transferred with 3-5 cm3 of water to an evaporating cup with a capacity of 50 cm3. Further - according to clause 3.7.

It is allowed to conduct a control experiment using a standard sample of copper composition, for example, OCO A1921X (only for elements whose content in CRM is certified). To do this, SS is analyzed according to the method.

3.9. Firing electrodes

To remove surface contaminants, the electrodes are annealed in a DC arc at 12 A for 20 s. Each pair of electrodes is subjected to firing cleaning immediately before analysis, including an electrode with a channel as an anode in the arc, and an electrode sharpened on a cone as an arc cathode.

4. CONDUCTING THE ANALYSIS

Each concentrate obtained from the analyzed sample or after a control experiment is placed in a graphite electrode channel with a diameter of 4 mm and a depth of 3 mm. Two electrodes are stuffed from each sample sample. Each of the comparison samples OS1-OS9 is placed in the channel of the same graphite electrodes.

Thus, six electrodes with sample concentrates, three electrodes with control experiment concentrates, and two electrodes with each of the reference samples (OC1, OS2, ...OC9) are obtained. The electrode with the impurity concentrate or the reference sample serves as the anode (lower electrode). The arc cathode is a graphite electrode sharpened into a cone. A DC arc of 10 A is ignited between the electrodes. The spectra are photographed on a spectrograph. Intermediate aperture 5 mm. The spectrograph slit width is 10 μm. Exposure time (until complete sodium burnout) - 30 s. During exposure, the distance between the electrodes is maintained at 3 mm. Spectral photographic plates are used: type 1 for registration in the wavelength range up to 300 nm; type 2 - for the wavelength range of 300-220 nm.

The exposed photographic plate is developed, washed with water, fixed, washed in running water for 15 minutes and dried.

5. PROCESSING THE RESULTS

5.1. In each spectrogram, the blackening of the analytical line of the element being determined (Table 2) and the nearby background (the minimum blackening next to the analytical line of the element being determined on any side, but on the same side in all spectra taken on the same plate) are photometered and the blackening difference is calculated. For each of the three samples, (=1, 2, 3) is calculated as the arithmetic mean of the values obtained from two spectrograms ; . Three values (=1, 2, 3), calculated for each sample, find the arithmetic mean. From the obtained average values, they pass to the corresponding values of the logarithms of the relative intensity, in accordance with the appendix to GOST 9717.3. According to the values and for comparison samples, a calibration graph is built in coordinates ().

table 2

Defined element	Wavelength of the analytical line, nm	Mass fraction of impurity, %









Aluminum

Manganese

According to the values for the concentrates of the analyzed sample, the values of the average mass fraction of the determined impurities in the concentrates of the sample are found according to the calibration curve. Similarly, according to the values for the concentrates of the control experience, the value of the average mass fraction of the determined impurities in the concentrates of the control experience is found.

The mass fraction of the th impurity in the analyzed sample in percent () is calculated by the formula

, (1)

Where is the mass of a sample of graphite powder with a mass fraction of sodium chloride 4% (collector), g;

The weight of the sample sample of copper, g;

The value of the average mass fraction of impurities in the concentrates of the analyzed samples, %;

The value of the average mass fraction of impurities in the concentrate of the control experiment, %.

The value should not exceed the lower limit of the determined values of the impurity mass fraction established for the method. If this condition is not met, it is necessary to thoroughly clean the room, workplaces, equipment used, change reagents, materials, and then repeat the analysis.

If the control experiment was carried out using a standard sample of copper composition, then the mass fraction of impurities in the analyzed sample in percent () is calculated by the formula

, (2)

Where is the certified value of the mass fraction of the element being determined in the standard sample, %.

For the final result of the analysis, the arithmetic mean of three determinations, each of which was obtained by two measurements, is taken.

5.2. When checking the convergence of the results of parallel determinations, from three values , , , obtained from two spectrograms each, taken for three weighed portions of the analyzed sample, choose the largest and smallest values, go from them to the values and , using the application GOST 9717.3 and find the corresponding values of the mass fraction of the impurity in sample and .

The ratio of the largest of the three results of parallel determinations to the smallest with a confidence probability = 0.95 should not exceed the values of the allowable discrepancies of the three results of parallel determinations.

For several values of the mass fraction of the element being determined, the allowable discrepancies in the results of three parallel determinations are given in Table 3.

Table 3

Defined element	Mass fraction, %	Absolute allowable discrepancies (the ratio of the largest to the smallest) of the results,%
		parallel definitions	analyzes
Aluminum (magnesium)





























Manganese

5.3. When comparing two results of the analysis, each of which was obtained by three parallel determinations, the ratio of the largest to the smallest results with a confidence probability = 0.95 should not exceed the values of the allowable discrepancy given in Table 3.

Permissible discrepancies for intermediate values of the mass fraction of the element being determined are calculated by linear interpolation.

5.4. The correctness of the analysis results is controlled using standard samples of copper composition or a certified mixture in which the certified value of the mass fraction of each of the elements to be determined differs from the mass fraction of this element in the analyzed sample by no more than 2 times. The result of the analysis is considered correct if the discrepancy between the found mass fraction of the element being determined and the corresponding certified value in the standard sample does not exceed the allowable discrepancies of the analysis results given in Table 3.

It is allowed to use the method of additions in accordance with GOST 25086.

Oxygen-free copper M0b is high-purity copper, where the copper content is not less than 99.99%, the oxygen content is 0.0003%, and other impurities are not more than 0.004%. It has important technological features: electrical conductivity (0.01707 - 0.01719 µOhm/m); thermal conductivity (386 - 390 W / m * hail); structure homogeneity; resistance to embrittlement (hydrogen). According to these indicators, oxygen-free copper grade M0b is quite a bit inferior to silver.
The classification of copper grades is made according to its chemical composition and is determined in GOST 859 - 2001. The production features of copper are determined by the content of impurities and oxygen content. High-purity copper (grades M00b and M0b) is oxygen-free copper, the oxygen content of which is allowed no more than 0.0003%.
The main method for obtaining oxygen-free copper is the remelting of cathodes in an inert, reducing atmosphere or in a vacuum.
Copper is supplied oxygen-free copper more often in the form of bars, wire rod, ingots.
Oxygen-free copper has been widely used in various areas of electrical engineering where high electrical conductivity of the material is required, but is also used in the following areas:
- aviation and space industry;
-instrument making;
-Atomic industry;
-electronic industry;
- production of medical equipment;
- production of vacuum equipment.
Oxygen-free copper grade M0b is used in the manufacture of:
- optical telecommunication cables, including submarine ones;
- switches;
- transformer windings;
- printed circuit boards;
- coaxial waveguides and cables;
- power distribution systems;
- electrovacuum devices.

LET'S SUPPLY COPPER M00b and M000b. ON ORDER!

Oxygen-free extra pure copper in ingots.

We have a possibility of delivery of especially pure oxygen-free copper in ingots.

Application.

The use of oxygen-free copper is due to its resistance to hydrogen embrittlement and low content of chemical elements volatile in vacuum at high temperatures, i.e. harmful impurities when used in the electronics industry and other areas.

High purity oxygen-free copper is used in electronic vacuum devices, electronic lamps, where only the absolute minimum of volatile impurities that can be released from copper under a combination of vacuum and high temperature is acceptable. Also, for such complex products as cryogenic and optical devices, high-quality oxygen-free copper is required.

Some other application examples:

* Magnetrons

* Vacuum capacitors

* Gaskets for vacuum equipment

* Bases or bases for semiconductors and substrates

* Military equipment, etc.

copper purity.

Currently used oxygen-free copper is “conditionally” subdivided into pure and high-purity oxygen-free copper.

Pure oxygen-free copper - guaranteed Cu + Ag content of at least 99.95-99-97% with a declared electrical conductivity of at least 100% IACS (M0b, Cu-OF).

High-purity (high purity) oxygen-free copper - guaranteed Cu content of at least 99.99% with a declared electrical conductivity of at least 101-102% IACS (M00b, Cu-OFE).

The purity of copper is determined by the content of the main substance, expressed as a percentage and is defined as the difference between 100% and the amount of controlled impurities.

Controlled impurities - a list of elements measured in a sample to determine purity.

Standards for determining the purity of copper.

Controlled impurities may be defined by various standards or specifications.

In Russia, the most famous standard is GOST 859-2001 (14 elements - O/P/S/Zn/Bi/Pb/Se/Te/Sn/Sb/As/Ni/Fe/Ag).

In European or other countries, these are the specifications for the Cu-OFE grade (16 elements - O / P / S / Zn / Cd / Bi / Pb / Se / Te / Sn / Mn / Sb / As / Ni / Fe / Ag - GOST 859 -2001 + Cd, Mn) or others.

Controlled impurities from the GOST 859-2001 and Cu-OFE standards are the most difficult to remove and affect the characteristics of copper products used in critical areas at high and cryogenic (low) temperatures, as well as in vacuum.

Controlled impurities may also be determined by other specifications agreed between the customer and the manufacturer.

As a rule, not only the list of controlled elements is determined, but also the limiting content of some of them.

GOST 859-2001 and specifications for the Cu-OF/Cu-OFE grade describe the requirements for pure and high-purity oxygen-free copper. This list of controlled elements from these standards and their requirements guarantees copper purity of at least 99.9x% and 99.99%, respectively. Individual results may be higher than 99.99%, but a minimum of 99.99% is guaranteed, i.e. no more than 100 ppm impurities.

According to standard technologies and the standard list of controlled impurities (GOST 859-2001 and Cu-OFE), it is almost impossible (at least in one technological cycle) to achieve a result above 99.99 (5-7)%, that is, the sum of impurities according to the standard list less than 30-50 ppm.

Supplied products. Characteristics.

Chemical purity.

For copper ingots with a purity higher than 99.99%, there are no generally accepted standards, at least they are not known to us yet. The manufacturer sets his own specifications describing his list of elements by which the purity is determined (100% - the sum of the described controlled impurities). As a rule, an abbreviated list of elements from the GOST 859-2001 and Cu-OF (E) standards is proposed, or another list in general that does not include elements that affect the characteristics of copper products used in critical areas at high and cryogenic (low) temperatures, and also in a vacuum.

Sometimes a metal standard is proposed to calculate the purity, including more than 60 metals. But again, extremely important harmful non-metal elements/impurities are not included.

The proposed standard is a purity of 99.999% (+) according to the list of controlled impurities from GOST 859-2001 and the Cu-OFE standard (16 elements - O / P / S / Zn / Cd / Bi / Pb / Se / Te / Sn / Mn / Sb / As / Ni / Fe / Ag).

Analysis methods - laser mass spectrometry, atomic emission spectrometry.

A typical analysis is 99.9991-99.9993%, which is limited by the capabilities of the analytical laboratory.

Important is not only the absolute purity, expressed as a percentage, but also the restriction on specific impurities that have a different effect on the characteristics of copper.

Samples can reach purity levels of 99.9994-99.9997% and higher. The purity does not change, the result of the measurement, expressed as a percentage, changes. These purity values are at the limit of the capabilities of analytical measurement methods, and if it is possible to consistently measure Oxygen (O) less than 2 ppm and Sulfur (S) less than 3 ppm, which is extremely difficult with available analytical methods for measuring purity.

Also, according to the metal standard, checks showed at least 99.999%.

Structure of copper.

The characteristics of copper products are influenced not only by chemical purity, but also by the crystal structure. A typical ingot of our copper consists of a few (limited/few) intergrown single crystals - typically 1-3 on the bottom + 2-7 on the top.

Characteristics of copper.

The characteristics of copper are determined by the quality of the copper. The quality of copper is determined by its chemical purity and structure. A "good" quality characteristic of copper is its resistivity, or electrical conductivity.

Measurements of the electrical conductivity of the supplied copper showed a result of the order of 104-105% IACS.

The electrical conductivity of grades M00b (GOST 859-2001) and Cu-OFE is declared at the level of 101-102% IACS.

The difference in the electrical conductivity of copper according to IACS leads to more significant differences in the characteristics at low temperatures - the specific (volume) resistance can differ by tens and hundreds of percent. The surface resistance (reflection coefficient) may differ, depending on the frequency, by tens or more percent.

The ingots are packed in double polyethylene (internal vacuum), two ingots in a wooden box.

Obtaining high-purity copper (99.999% Cu and above) can be carried out in three ways: repeated electrolytic refining, zone melting and electron beam melting.
Re-electrolytic refining can be carried out in sulfate and nitric acid electrolyte.
On fig. 33 is a diagram of the repeated electrolytic refining of copper. According to this scheme, the electrolytic baths are connected in series, with cathode copper from the first baths being used as anodes for subsequent baths, in which extra pure copper is obtained. The electrolyte (1-2-n. Cu2+1 - 1.5-n. H2SO4) is prepared from scraps of obtained extra pure copper. Process temperature 55-60°C, current density 120-150 A/m2. When dendritic copper is formed, pure alcohol (4 g/l) is added to the electrolyte. The copper obtained in this way (99.995% Cu) contains the following impurities: 2*10v-4% As, 2*10v-4% Sb, 1*10v-4% Ag, 2*10v-4 - 5*10v-4% S and 5 * 10v-3% O.

To obtain even more pure sulfur-free copper, Baimakov and Syrovegin investigated the possibility of refining copper in chloride and nitric acid electrolytes. The disadvantage of using a chloride electrolyte (200 g/l NaCl+, 150 g/l HCl and 50 g/l CuCl2) is the transition of arsenic and antimony impurities into the cathode copper, which is explained by the more electropositive potentials of these impurities in the chloride electrolyte compared to the equilibrium potential of copper (0 .02 c). For antimony it is 0.087 V, for arsenic 0.275 V and for bismuth 0.06 V.
To obtain high-purity copper, it is more expedient to use a nitrate electrolyte. The electrical conductivity of copper nitrate solutions is much higher than copper sulfate solutions and reaches its highest value at a copper concentration in the solution of about 100 g/l. The concentration of the free acid in the solution must be sufficient to prevent precipitation of the main salts of impurities. The precipitation of antimony and arsenic impurities on the cathode occurs at more electronegative potentials than the equilibrium potential of copper, the value of which is slightly higher than the value of the standard potential of copper in a sulfate solution, and at 20 ° C is 0.346 V. The discharge of antimony and arsenic ions proceeds with exceptionally high polarization, which explains the low probability of a joint discharge of copper ions and impurities. The high chemical polarization of the discharge of impurity ions is explained by the formation of an adsorption near-cathode layer of hydroxides and basic salts of impurities, which requires a higher activation energy, as well as by the discharge of these impurities from complex ions (AsO3- and SbO3-).
A sharp increase in the content of impurities in cathode copper was observed at an acid concentration of less than 0.1-0.15-n., which is explained by increased hydrolysis of antimony and arsenic salts and the capture of colloidal hydroxide particles in the cathode precipitate.
The optimal composition of the electrolyte: 1.5-2.5-n. Cu and 0.1-0.15-n. HNO3 (free). For a deeper purification of the electrolyte from sulfur in order to bind SO4 ions, about 0.5 g / l x is added to it. h. Ba (NO3) 2- After a daily settling of the heated solution, it is decanted and carefully filtered. This makes it possible to reduce the sulfur impurity content in the electrolyte to 1*10w-3 g/l SO2-.
If the electrolyte solution is treated with barium nitrate, then copper containing no more than 1 * 10v-8% S can be obtained. The optimum process temperature is 35 ° C, the current density is 150-250 a / m2.

Electrolysis is carried out in vinyl plastic baths with anode diaphragms made of cellophane or fabric impregnated with collodion (Fig. 34). The anolyte, enriched with impurities and suspension, is periodically (1 time in 12-24 hours) removed from the anode space, limited by diaphragms, and replaced with a depleted catholyte.
Using this electrolytic refining process, it is possible to obtain copper with a purity of 99.999% containing the following amounts of impurities:<3*10в-4 % As, <2*10в-4% Sb, <1*10в-4% Sn, <1*10в-4% Zn, <2*10в-4% Mn, <3*10в-4% Pb, <1*10в-4% Bi, <3*10в-4% Fe, <7*10в-4% Ni, <3*10в-4% Si, <2*10в-4% Mg.
The sulfur content in such a metal cannot be detected by conventional methods of analysis.
Zone recrystallization of copper
For the first time, the purification of copper by zone melting was studied by Wernick, Kunzler and Olsen. Melting was carried out in a graphite boat in a quartz tube with induction heating in an atmosphere of purified nitrogen. According to this study, sulfur, selenium, calcium and arsenic are unfavorable impurities.
Tolmi and Robins zone-melted pure copper containing 99.99% Cu and virtually free of oxygen. The content of the main impurities in it was 3*10v-3% S, 3*10v-3% Ag and 7*10v-4% Ni.
Copper was placed in boats made of high purity graphite and degassed in a vacuum at 2800°C. The length of the copper ingot was 200 mm and the diameter was 9 mm. Ingots before zone melting were mechanically cleaned and treated in 60% nitric acid. The boat with the ingot was installed in a quartz tube 25 mm in diameter, through which purified dry hydrogen was passed under a pressure slightly above atmospheric. The length of the melted zone is 22 mm, the ratio of the length of the zone to the length of the ingot is l/z = 1/10, the speed of movement of the zone is 11 mm/h, the heating of the zone is induction.
After three passes of the zone, impurities of chromium, silver, manganese, and tin were displaced to the opposite end of the ingot, and the lead impurity was completely removed from the initial part of the ingot. Copper was not purified from impurities of cobalt, iron and nickel.

On fig. 35 shows the distribution of the main impurities along the length of the copper ingot after nine zone passes. After eighteen passes of the zone, approximately 1/4 of the ingot was spectrally pure from impurities of lead, silver, silicon, manganese and tin, and at a distance of 12 cm, i.e., in the center of the ingot, the content of all impurities decreased significantly.
According to the phase diagrams of copper - an impurity, the distribution coefficient for iron, cobalt and nickel should be greater than one, and for other impurities - less. On the basis of the phase diagrams, the equilibrium ones were calculated, and from the experimental data, the effective distribution coefficients of individual impurities in copper during its zone refining were found. These data are collected in table. 16.

From the data in Table. 16 it follows that the values of the distribution coefficients of the given impurities are not favorable enough, since they are relatively close to unity. Better than others in zone refining, silicon and silver impurities should be removed.
According to the study under consideration, in the central part of the ingot, all impurities were removed on average by 70%. And since in the original copper the total content of impurities was approximately 0.01%, then, consequently, as a result of zone melting, copper with a purity of 99.997% was obtained.
Electron-beam melting of copper increases its purity, sharply reduces the content of gases and volatile impurities in it, increasing the plasticity and electrical conductivity of the metal. In this case, some losses of copper are observed due to the noticeable elasticity of its vapors under the conditions of electron beam melting.

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