GOST 1652.6-77

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  ГОСТ 1652.6-77

GOST 1652.6−77 Alloys copper-zinc. Methods for determination of antimony (with Amendments No. 1, 2, 3)

GOST 1652.6−77

Group B59

STATE STANDARD OF THE USSR

ALLOYS COPPER-ZINC

Methods for determination of antimony

Copper-zinc alloys. Methods for the determination of antimony

AXTU 1709

Date of introduction 1978−07−01

INFORMATION DATA

1 DEVELOPED AND INTRODUCED by the Ministry of nonferrous metallurgy of the USSR

DEVELOPERS

Y. F. Chuvakin, M. B. Taubkin, AA. Nemodruk, N. In. Egiazarov (supervisor), I. A. Vorobyev

2. APPROVED AND promulgated by the Decree of the State Committee of standards of Ministerial Council of the USSR from 27.04.77 N 1062

3. REPLACE GOST 1652.6−71

4. REFERENCE NORMATIVE AND TECHNICAL DOCUMENTS

5. Resolution of the state standard from 28.12.92 N 1525 removed the limitation of the validity period

6. REPRINT (July 1991) with Changes No. 1, 2, 3, approved in October 1981, November 1987, December 1992 (IUS 12−81, 2−88, 3−93)


This standard specifies the extraction-photometric method for the determination of antimony with crystal violet (when the mass fraction of antimony from 0.001 to 0.3%), extraction-photometric method for the determination of antimony with brilliant green (when the mass fraction of antimony from 0.1 to 0.3%) and atomic absorption method for the determination of antimony (in mass fraction of antimony from 0.001 to 0.2%) in copper-zinc alloys according to GOST 15527, GOST GOST 17711и 1020.

(Changed edition, Rev. N 2).

1. GENERAL REQUIREMENTS

1.1. General requirements for methods of analysis GOST 25086 with the Supplement according to claim 1.1 GOST 1652.1.

(Changed edition, Rev. N 2).

2. EXTRACTION-PHOTOMETRIC METHOD FOR THE DETERMINATION OF ANTIMONY WITH CRYSTAL VIOLET

2.1. The essence of the method

The method is based on extraction of pentavalent antimony toluene in the form of hexachlorobuta crystal violet and measuring the optical density of the extract after separation of antimony deposition it with manganese dioxide and dissolving the precipitate in hydrochloric acid.

2.2. Apparatus, reagents and solutions

Photoelectrocolorimeter or spectrophotometer.

Nitric acid according to GOST 4461 and diluted 1:1 and 1:100.

Hydrochloric acid according to GOST 3118 and diluted 7:3, 3:1 and 1:1.

Hydrofluoric acid according to GOST 10484.

Sulfuric acid according to GOST 4204, and diluted 1:1 and 1:5.

Ammonia water according to GOST 3760 and diluted 1:1.

Potassium permanganate according to GOST 20490 and a solution of 10 g/DM.

Manganese sulfate according to GOST 435, a solution of 50 g/DM.

Tin dichloride, solution 100 g/lin hydrochloric acid, diluted 1:1.

Sodium atomistically according to GOST 4197, solution 100 g/DM.

Urea according to GOST 6691, saturated solution; prepared as follows: 100 g of urea dissolved in 100 cmof hot water.

Crystal violet solution 2 g/DM.

Toluene according to GOST 5789.

Sodium sulphate anhydrous according to GOST 4166.

Antimony GOST 1089, brand Su00.

Solutions of antimony

Solution A, prepared as follows: 0.1 g of antimony is dissolved by heating in 50 cmof concentrated sulfuric acid. The solution was transferred to a volumetric flask with a capacity of 1 DM, made up of 175 cmof sulphuric acid diluted 1:1, cooled, made up to the mark with water and mix.

1 cmof the solution contains 0.0001 g of antimony.

Solution B is prepared as follows: 10 cmof solution A is placed in a volumetric flask with a capacity of 100 cm, 70 cm pourconcentrated hydrochloric acid, diluted to the mark with water and mix.

1 cmof solution B contains 0,00001 g of antimony.

2.3. Analysis

2.3.1. A sample of alloy weighing 0.5 g was dissolved with heating in 5−10 cmof nitric acid, diluted 1:1 in glass with a capacity of 250 cm, covered with watch glass. The solution was cooled, the watch glass rinsed with water and dilute with water to 50 cm. In the analysis of the silicon brass alloy of the sample 0.5 g was placed in a platinum Cup, add 10 cmof nitric acid, diluted 1:1, 2 cmhydrofluoric acid and heated until dissolved. After cooling the walls of the Cup is washed with a small amount of water, add 3 cmof concentrated sulfuric acid and evaporated to start the selection of a white smoke of sulfuric acid. The Cup is cooled, wash the walls with a little water and repeat the evaporation to start the selection of a white smoke of sulfuric acid. After cooling, dissolve salt in 5 cmof nitric acid, diluted 1:1, transfer the solution into a glass with a capacity of 250 cm, and diluted with water to a volume of 50 cm. Further, for both conventional and siliceous brass resulting solution is neutralized with ammonia until the appearance of the precipitate copper hydroxide, which persisted during stirring, and add a pipette of 0.5 cmof nitric acid diluted 1:1 add 1 cmof solution of potassium permanganate, cover the beaker watch glass and the solution is heated nearly to boiling. Then add 1 cmof manganese sulfate and boiled for 2 min. the Solution was allowed to stand for 1 h, after which the precipitate was filtered off on a tight filter. The beaker and precipitate was washed 4−5 times with hot nitric acid, diluted 1:100 before the disappearance of coloration of nitrate of copper.

The filter with the sediment was transferred to a glass that has been used for the precipitation, add 10−15 cmof concentrated sulfuric acid, 20−25 cmof concentrated nitric acid and evaporate the solution to start the selection, the dense white smoke of sulfuric acid. If the solution is colored, add another 5−10 cmof concentrated nitric acid and repeat the evaporation. The glass is cooled, the side of the Cup washed with water and evaporated the solution until damp salts. After cooling, to the residue is added 7 cmof hydrochloric acid diluted 7:3, and heated at 80−95 °C until complete dissolution of salts. The solution was transferred to a separatory funnel with a capacity of 150 cm, the glass is washed with 3 cmof hydrochloric acid diluted 7:3 and it bring the solution volume up to 10 cm. When the mass fraction of antimony in excess of 0.005% solution transferred to an appropriate volumetric flask (see table 1) and dilute to the mark with hydrochloric acid diluted 7:3.

Table 1

In this case, select the specified in table.1 aliquot part of the solution in the separatory funnel with a capacity of 150 cmand add hydrochloric acid diluted 7:3, to a volume of 10 cm. Add to separatory funnel, drop 1−2 drops of solution of tin dichloride to a bleaching solution, mix and leave for 1 min Then add 1 cmof a solution of sodium attestatio, funnel closed with a stopper and shake for 2 min. After that open the funnel. After 2 min add 1 cmof a solution of urea and stirred for 30 s. Then add the 68 cmof water, 10 drops of crystal violet solution, mix, add 25 cmof toluene and extracted for 1 min.

After phase separation, the lower aqueous layer is discarded and the organic layer is poured into a dry beaker with a capacity of 50 cmcontaining 0.2 g of anhydrous sodium sulfate, and measure the optical density of the obtained extract on a photoelectrocolorimeter with a red filter at a wavelength of 590 nm in a cuvette with a layer thickness of 2 cm or spectrophotometer in a cuvette with a layer thickness of 2 cm at a wavelength of 610 nm. Solution comparison is toluene.

The content of antimony found by the calibration schedule.

Note. If the analysis will not be completed during the day, it can be interrupted after the deposition of antimony with manganese dioxide or after evaporation of a solution of sulfuric acid.

2.3.2. Construction of calibration curve

In a separating funnel with a capacity of 150 cmadministered 0; 0,5; 1,0; 1,5; 2,0; 2,5; 3,0 and 3.5 cmof a solution and add hydrochloric acid diluted 7:3, up to 10 cm. Add 1−2 drops of solution of tin dichloride, mix and leave for 1 min. Further analysis are as indicated in claim 2.3.1.

On the found values of the optical densities of the solutions and the corresponding concentrations of antimony in building the calibration curve.

3. EXTRACTION-PHOTOMETRIC METHOD FOR THE DETERMINATION OF ANTIMONY WITH BRILLIANT GREEN

3.1. The essence of the method

The method is based on extraction with toluene painted in the blue-green color hexachlorobuta brilliant green and measurement of the optical density of the extract.

3.2. Apparatus, reagents and solutions

Photoelectrocolorimeter or spectrophotometer.

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

Hydrochloric acid according to GOST 3118, diluted 3:1 and 1:1.

Sulfuric acid according to GOST 4204, and diluted 1:5.

Tin dichloride, a freshly prepared solution of 100 g/lin hydrochloric acid, diluted 1:1.

Sodium nitrate according to GOST 4197, solution 100 g/DM.

Urea according to GOST 6691, saturated solution; prepared as follows: 100 g of urea dissolved in 100 cmof hot water.

Diamond green, a solution of 2 g/DM.

Toluene according to GOST 5789.

Antimony GOST 1089, brand Su00.

Standard solutions of antimony

Solution A, prepared as follows: 0.05 g of antimony is dissolved by heating in 25 cmconcentrated sulphuric acid. The solution was cooled, transferred to a volumetric flask with a capacity of 500 cm, made up to the mark with sulfuric acid diluted 1:5, and stirred.

1 cmof the solution contains 0.0001 g of antimony.

Solution B is prepared as follows: 10 cmof the solution And transferred to a volumetric flask with a capacity of 100 cm, made up to the mark with hydrochloric acid, diluted 3:1, and stirred.

1 cmof solution B contains 0,00001 g of antimony. Solution B is prepared on the day of application.

Sodium sulphate anhydrous according to GOST 4166.

3.3. Analysis

0.1 g of alloy is dissolved in 10 cmof nitric acid, diluted 1:1 in glass with a capacity of 250 cm, covered with watch glass during heating. After dissolution of the sample clock glass and sides of beaker rinse with water, add 3 cmof concentrated sulphuric acid and evaporated until the appearance of sulphuric acid fumes. Cool the solution, wash the side of the Cup with a little water and repeat the evaporation. To the residue poured 20 cmof hydrochloric acid, diluted 3:1, dissolved salts, and the solution was transferred to volumetric flask with a capacity of 100 cm, and then topped to the mark with hydrochloric acid, diluted 3:1, and stirred.

In a separating funnel with a capacity of 150 cmis introduced 5 cmof the analyzed solution, add two drops of solution of chloride of tin, mix and leave for 1 min and Then injected 1 cmof solution azotistykh sodium, mixed well and left for 5 min. then add 1 cmof a saturated solution of urea, mix 30 s and diluted with water to 50 cm. Add 1 cmof a solution of brilliant green, 30 cmof toluene and extracted by shaking for 1 min.

After phase separation, the lower aqueous layer is discarded and the organic layer is poured into a dry beaker with a capacity of 50 cmcontaining 0.3−0.5 g of dehydrated sodium sulfate. After 10 minutes measure the optical density on the spectrophotometer at a wavelength of 640 nm or photoelectrocolorimeter with a red filter at a wavelength of 590−610 nm in a cuvette with a layer thickness of 1 cm with a Solution of comparison is toluene. The content of antimony found by the calibration schedule.

3.3.1. Construction of calibration curve

In a separating funnel with a capacity of 150 cmenter 0; 0,5; 1,0; 1,5; 2,0 and 2,5 cmstandard solution B, add two drops of solution of tin dichloride, mix and leave for 1 min then inject 1 cmof a solution of sodium attestatio and further analysis are as indicated in claim 3.3.

On the found values of optical densities of solutions and their corresponding grades of antimony building a calibration curve.

4. PROCESSING OF THE RESULTS

4.1. Mass fraction of antimony () in percent is calculated by the formula

,

where is the mass of antimony, was found in the calibration schedule g;

 — the weight of the portion corresponding to aliquote part of the solution,

4.2. The absolute discrepancies in the results of parallel measurements ( — convergence) must not exceed the permissible values given in table.2.

Table 2

(Changed edition, Rev. N 2, 3).

4.3. The absolute discrepancies of the analysis results obtained in two different laboratories or two of the results of analysis obtained in the same laboratory but under different conditions (the reproducibility) shall not exceed the values specified in table.2.

4.4. The control accuracy of the analysis carried out according to State standard samples (GSO) or industry standard sample (CCA), or by standard samples of the enterprise (SOP) copper-zinc alloys, approved GOST 8.315, or by additives, or by comparing the results obtained by another method in accordance with GOST 25086.

4.4.1−4.4.3. (Deleted, Rev. N 3).

5. ATOMIC ABSORPTION METHOD

51. The essence of the method

The method is based on dissolving the sample in a mixture of hydrochloric and nitric acids and measuring the atomic absorption of antimony in the flame acetylene-air, using radiation with a wavelength of the amount of 231.1 nm, or the measurement under the same conditions the atomic absorption of antimony from the environment of organic solvents after preliminary gidratirovannogo her coprecipitation on manganese dioxide.

5.2. Apparatus, reagents and solutions

Atomic absorption spectrometer with all accessories.

Electrodeless lamp or a lamp with a hollow cathode for antimony.

Hydrochloric acid according to GOST 3118 and diluted 2:1, 1:1 and 1:5.

Nitric acid according to GOST 4461 and diluted 1:1, 1:2 and 1:100.

A mixture of hydrochloric acid (1:1) and nitrogen (1:1) in a 1:1 ratio.

Ammonia water according to GOST 3760.

Potassium permanganate according to GOST 20490, a solution of 30 g/DM.

Manganese sulfate according to GOST 435, a solution of 80 g/DM.

Hydrogen peroxide according to GOST 10929.

Rectified ethyl alcohol according to GOST 18300.

Methyl isobutyl ketone.

A mixture of ethanol and methyl isobutyl ketone, in a ratio of 1:1.

A mixture of ethyl alcohol, methyl isobutyl ketone and concentrated hydrochloric acid in the ratio 4,5:4,5:1.

Manganese metal according to GOST 6008, with a mass fraction of antimony less than 0.0005%.

The solution of manganese: 10 g of manganese dissolved in 40 cmof concentrated nitric acid removed the oxides of nitrogen by boiling, adding 250 cm.of concentrated hydrochloric acid, add water to 1 DMand stirred.

10 cmof the solution contains 100 mg of manganese.

Copper metal according to GOST 859, with a mass fraction of antimony less than 0.0005%.

The copper solution: 50.0 g of copper is dissolved in 400 cmof nitric acid, diluted 1:1, boiling removes oxides of nitrogen, the solution was cooled, transferred to a volumetric flask with a capacity of 500 cm, made up to the mark with water and mix.

1 cmof solution contains 100 mg of copper.

Antimony GOST 1089, brand Su00.

Solutions of antimony

Solution a: 0.5 g of antimony is dissolved in 200 cmof concentrated hydrochloric acid and 2 cmof concentrated nitric acid.

After dissolution and cooling, the solution is transferred into a measuring flask with volume capacity of 1000 cm, made up to the mark with hydrochloric acid diluted 1:5, and stirred.

1 cmof solution A contains 0.5 mg of antimony.

Solution B: 20 cmsolution And taken in a volumetric flask with a capacity of 100 cm, made up to the mark with hydrochloric acid diluted 1:5, and stirred.

1 cmof solution B contains 0.1 g of antimony.

5.3. Analysis

5.3.1. A sample of alloy weighing 5 g (with mass fraction of antimony from 0.001 to 0.005%) or 2 g (for mass concentration in excess of 0.005% to 0.05%) was placed in a beaker with a capacity of 600 cmand dissolve in 50 and 20 cmof a mixture of acids. The solution is diluted with water to 150 cm, neutralized with ammonia before the advent of unfading during the mixing of the precipitate, dissolve it drop by drop nitric acid, diluted 1:2, and top up with water to 300 cm.

Then the solution was added 2.5 cmof a solution of sulphate of manganese, heated to boiling, add 3 cmof potassium permanganate solution and boil the solution 1 min to coagulate the precipitate. After 30 min the precipitate was filtered off on a medium density filter and washed with hot nitric acid, diluted 1:100.

The precipitate is washed with water in a glass, which conducted the deposition, and the residue on the filter was dissolved 30 cmhot hydrochloric acid, diluted 2:1, while adding a few drops of hydrogen peroxide. The filter is washed with hot hydrochloric acid (1:5), and the solution was evaporated on water bath to a moist residue. To the residue add 5 cmof concentrated hydrochloric acid and heated in a water bath to dissolve the residue, cool and transfer the solution into volumetric flask with a capacity of 50 cm, rinse the glass with a mixture of ethanol and methyl isobutyl ketone, made up to the mark with the same mixture and stirred.

Measure the atomic absorption of antimony in the sample solution in parallel with the solutions to construct the calibration curve and the solution in the reference experiment in the flame acetylene-air, using radiation with a wavelength of the amount of 231.1 nm. The instrument zero set mixture: hydrochloric acid, ethyl alcohol and methyl isobutyl ketone.

5.3.2. When the mass fraction of antimony over 0.05 to 0.2% a sample of alloy weighing 2 g was dissolved with heating in a glass with a capacity of 250 cmto 20 cmof a mixture of acids. The solution was cooled, transferred to a volumetric flask with a capacity of 100 cm, made up to the mark with hydrochloric acid diluted 1:5, and stirred. Measure the atomic absorption of antimony in the sample solution in parallel with the solutions to construct the calibration curve and the solution in the reference experiment, using radiation with a wavelength of the amount of 231.1 nm. The zero of the instrument set on the water.

5.3.3. Construction of calibration curve

5.3.3.1. When the mass fraction of antimony from 0.001 to 0.005% in seven of the eight cups capacity 100 cmselect 0,5; 1,0; 2,0; 4,0; 6,0; 8,0 and 10.0 cmstandard solution B, which corresponds to 0,05; 0,1; 0,2; 0,4; 0,6; 0,8 and 1.0 mg of antimony. All the glasses are poured 10 cmof a solution of manganese and evaporated in a water bath to a moist residue, which is dissolved in 5 cmof hydrochloric acid and then act as described in paragraph 5.3.1.

5.3.3.2. For the mass concentration of antimony of more than 0.05 to 0.2% in five out of six volumetric flasks with a capacity of 100 cmselect 1,0; 2,0; 4,0; 6,0 and 8,0 cmstandard solution A, which corresponds to 0,5; 1,0; 2,0; 3,0 and 4,0 mg of antimony. All flasks is poured a solution of copper in accordance with its concentration in the sample solution, add hydrochloric acid, diluted 1:5, up to the mark, stirred and fed as specified in claim 2.4.2.

5.4. Processing of the results

5.4.1. Mass fraction of antimony () in percent is calculated by the formula

,

where is the concentration of antimony in the analyzed solution samples, was found in the calibration schedule, g/cm;

 — the concentration of antimony in solution in the reference experiment, was found in the calibration schedule, g/cm;

 — volume of the volumetric flask to prepare the final sample solution, cm;

 — weight of sample, g

.

5.4.2. The absolute discrepancies in the results of parallel measurements ( — convergence) must not exceed the permissible values given in table.2.

(Changed edition, Rev. N 2, 3).

5.4.3. The absolute discrepancies of the analysis results obtained in two different laboratories or two of the results of analysis obtained in the same laboratory but under different conditions (the reproducibility) shall not exceed the values specified in table.2.

(Changed edition, Rev. N 3).

5.4.4. The control accuracy of the analysis carried out according to State standard samples (GSO) or industry standard sample (CCA), or by standard samples of the enterprise (SOP) copper-zinc alloys, approved GOST 8.315, or by additives, or by comparing the results obtained by another method in accordance with GOST 25086.

5.4.4.1−5.4.4.3. (Deleted, Rev. N 3).