GOST 1652.13-77

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  ГОСТ 1652.13-77

GOST 1652.13−77 Alloys copper-zinc. Methods for determination of phosphorus (with Amendments No. 1, 2, 3)

GOST 1652.13−77

Group B59

STATE STANDARD OF THE USSR

ALLOYS COPPER-ZINC

Methods for determination of phosphorus

Copper-zinc alloys.
Methods for the determination of phosphorus

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, A. A. Nemodruk, N. In. Egiazarov (head), A. I. Vorobyov

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 1652.13−71

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 1997) with Amendments No. 1, 2, 3, approved in October 1981, November 1987-December 1992 (IUS 12−81, 2−88, 3−93)


This standard sets the photometric method for the determination of phosphorus (at a mass fraction of phosphorus from 0.005 to 0.1%), extraction-photometric method for the determination of phosphorus (at a mass fraction of phosphorus from 0.002 to 0.04%) in copper-zinc alloys according to GOST 15527, GOST and GOST 17711 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. THE PHOTOMETRIC METHOD FOR THE DETERMINATION OF PHOSPHORUS

2.1. The essence of the method

The method is based on formation of yellow phosphomolybdenum complex and measuring its optical density without prior separation of the phosphorus.

2.2. Apparatus, reagents and solutions

Photoelectrocolorimeter or spectrophotometer.

Hydrochloric acid according to GOST 3118.

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

The mixture of acids to dissolve is prepared by mixing 400 cmof hydrochloric acid, 100 CC. nitric acid and 500 cmof water.

Ammonia water according to GOST 3760.

Undeviatingly ammonium (meta) according to GOST 9336, is prepared as follows: 2,5* the drug is dissolved in 500−700 cmof hot water in a volumetric flask with a capacity of 1 DM, cooled to room temperature, add 20 cmof concentrated nitric acid, made up to the mark with water, mixed and filtered.
________________
* The text of the document matches the original. — Note the manufacturer’s database.


Ammonium molybdate according to GOST 3765, recrystallized from alcoholic solution, a freshly prepared solution of 100 g/DM.

The recrystallization of ammonium molybdate is carried out as follows: 70 g of drug is dissolved in 400 cmof hot water and filtered twice through the same filter. To the filtrate is added 250 cm.of ethanol and after standing for 1 h the precipitated crystals are sucked off and repeat the recrystallization. After the second suction, the crystals washed 2−3 times with a mixture of alcohol and water (5:8) and dried in air.

The technical rectified ethyl alcohol according to GOST 18300 and diluted 5:8.

Hydrogen peroxide according to GOST 177, a 30% solution.

High purity copper with a phosphorus content of not more than 0,0002%.

Potassium permanganate according to GOST 20490, 0.2 mol/DMsolution.

Hydrofluoric acid according to GOST 10484.

Potassium phosphate odnosemjannyj.

Sodium phosphate disodium.

The phosphorus standard solution is prepared as follows: 0,4395 g of single phosphate or potassium 0,4586 g twosemester sodium phosphate, previously dried at 105 °C to constant weight, is placed in a volumetric flask with a capacity of 1 DM, is dissolved in water, made up to the mark with water and mix.

1 cmof the solution contains 0.0001 g of phosphorus.

(Changed edition, Rev. N 3).

2.3. Analysis

2.3.1. A sample of alloy weighing 1 g is placed in a beaker with a capacity of 250 cm, and dissolved in 20 cmof the mixture for dissolution. Beaker cover watch glass. Initially dissolved without heating, and after dissolving the bulk of the sample is under heating until complete dissolution of the sample.

In the analysis of silicon alloy sample is placed in a platinum Cup and dissolved in 15 cmof concentrated nitric and 2 cmhydrofluoric acid. The solution was evaporated to dryness, add 5 cmof concentrated nitric acid. The evaporation is repeated four more times, adding each time 5 cmof concentrated nitric acid. The residue is dissolved in 10 cmof nitric acid, diluted 1:1, transfer the solution into a glass with a capacity of 250 cm, rinse the Cup a small amount of water and add 5 cmof hydrochloric acid. The solution is heated to a temperature of 30−40 °C, add dropwise a solution of potassium permanganate until the appearance of purple colour and leave for 5 min. the solution was Then heated to boiling, boiled for 1 min and cooled to 30−40 °C.

To the obtained solution poured 1 cmof hydrogen peroxide, heated to boiling and boiled for 3 min to remove the oxides of nitrogen (do not allow the violent and prolonged boiling of a solution to avoid loss of solution and phosphorus).

Wash the glass with water, pour 10 cmof a solution of ammonium anadalucia 10 cmof molybdate ammonium solution, stirred well, cooled, transfer the solution into a volumetric flask with a capacity of 50 cm, made up to the mark with water and mix.

Measure the optical density in a cuvette with a layer thickness of 3 cm on a photoelectrocolorimeter with a blue color filter at a wavelength of 434 nm or in a cuvette with a layer thickness of 1 cm on the spectrophotometer at a wavelength of 315 nm against the solution of the control sample.

2.3.2. Preparation of the solution of the control sample

Take a sample of high purity copper to copper content in solution was close to its content in the sample, and dissolved in 20 cmof a mixture of acids. Further analysis are as indicated in claim 2.3.1.

2.3.3. Construction of calibration curve

In glasses with a capacity of 250 cmis placed 1 g of pure copper, the flow consistently 0; 2,0; 4,0; 6,0; 8,0; 10,0 and 12.0 cmstandard solution of phosphorus was added 20 cmof the mixture of acids and further analysis are as indicated in claim 2.3.1. As a solution comparison, using a solution in which was added a solution of phosphorus.

According to the obtained values of optical density of solutions and the corresponding content of phosphorus build a calibration curve.

2.4. Processing of the results

2.4.1. Mass fraction of phosphorus in percent is calculated by the formula

,

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

 — the weight of the portion of alloy,

2.4.2. The absolute discrepancies in the results of parallel measurements ( — convergence) must not exceed the permissible values given in table.1.

Table 1

2.4.3. 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.

2.4.2, 2.4.3. (Amended, ISM, N, 2, 3).

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 under GOST 8.315, or by a method of additives in accordance with GOST 25086.

(Changed edition, Rev. N 3).

2.4.4.1, 2.4.4.2. (Deleted, Rev. N 3).

3. EXTRACTION-PHOTOMETRIC METHOD FOR THE DETERMINATION OF YELLOW PHOSPHORUS BY THE MOLYBDOPHOSPHORIC HETEROPOLYACID IN THE ALLOYS CONTAINING ARSENIC

3.1. The essence of the method

The method is based on formation of yellow phosphorus the molybdophosphoric complex at pH 1.5 extracted with a mixture of chloroform and n-butyl alcohol, and measuring the optical density of the extract.

3.2. Apparatus, reagents and solutions

Photoelectrocolorimeter or spectrophotometer.

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

Hydrofluoric acid according to GOST 10484.

Crystal violet solution 10 g/DM.

Ammonia water according to GOST 3760.

Ammonium molybdate according to GOST 3765, a solution of 50 g/DM.

The recrystallization of ammonium molybdate is carried out as specified in clause 2.2.

The technical rectified ethyl alcohol according to GOST 18300 and diluted 5:8.

Sodium chloride according to GOST 4233.

Normal butyl alcohol according to GOST 6006−78 distilled at 118 °C.

Chloroform.

Mix for extractions; prepared as follows: mix n-butyl alcohol and chloroform in a ratio of 1:3.

Mixture for washing, prepared as follows: to 500 cmof water was added 120 cmof nitric acid diluted 1:2, 30 cmof ammonium molybdate solution and 40 cmn-butyl alcohol.

Sodium sulphate anhydrous according to GOST 4166.

Potassium phosphate according to GOST odnosemjannyj 4198.

The standard solutions of phosphorus.

Solution A, prepared as follows: 0,4395 g potassium phosphate, dried at 105 °C, dissolved in a volumetric flask with a capacity of 1 DMand topped to the mark with water.

1 cmof the solution contains 0.0001 g of phosphorus.

Solution B is prepared as follows: 10 cmof the solution And transferred to a volumetric flask with a capacity of 100 cmand top up with water to the mark.

1 cmof solution B has the 0.00001 g of phosphorus.

3.3. Analysis

3.3.1. For alloys not containing silicon and tin

The weight of the alloy depending on the mass fraction of phosphorus (table.2) is placed in a beaker with a capacity of 250 cmand dissolved in 10−25 cmof nitric acid, diluted 1:1, when heated.

Table 2

After dissolution of the sample wall and the glass is washed with water, the solution was boiled to remove oxides of nitrogen, diluted with water to 75 cmand neutralized with ammonia to pH 1.5 by controlling the pH drip test with crystal violet solution or indicator paper. The solution was transferred to a separatory funnel with a capacity of 250 cm, and dilute with water to 100 cm. Add 6 cmof molybdenic acid ammonium solution and leave for 10 minutes Add 8 cmof n-butyl alcohol and stirred vigorously to saturate the aqueous solution with alcohol, add 10 cmof nitric acid, diluted 1:2 and stirred. The yellow complex of the molybdophosphoric acid and extracted with a 10 cmmixture for extraction, gently shaking 1 min After phase separation, the lower organic phase was transferred to another separatory funnel.

To the aqueous phase is added again 5 cmof the mixture for extraction and extracted 1 min Extraction with 5 cmof the mixture for extraction was repeated once more. The last extract should be colorless. The organic layer is washed in a separating funnel 50 cmmixture for washing, stirring 30 s. After the partition phase the lower layer is drained into a dry volumetric flask with a capacity of 25 cmcontaining 0.2 g of anhydrous sodium sulfate, stirred, and topped to the mark with the mixture for extraction.

The optical density of the extract is measured on a photoelectrocolorimeter with a purple or blue color filter (at a wavelength of 420−430 nm) in a cuvette with a layer thickness of 2 cm or on the spectrophotometer at a wavelength of 420 nm in a cuvette with a layer thickness of 1 cm relative to the solution of the control sample.

3.3.2. For alloys containing silicon

The mass of the sample (see table.2) is placed in a platinum Cup and dissolved in a mixture of 15 cmof nitric acid, diluted 1:1, and 2−3 cmhydrofluoric acid with gentle heating and evaporated to dryness. Rinse the walls of the Cup 10 cmof concentrated nitric acid and repeat the evaporation to dryness three more times, each time adding 10 cmof concentrated nitric acid.

To the dry residue add 10 cmof nitric acid, diluted 1:1, dissolved salts, and the solution transferred to a beaker with a capacity of 250 cm. The Cup is then rinsed with water several times for 10 cmand the solution was boiled to remove oxides of nitrogen, then diluted with water to 75 cmand further analysis are as indicated in claim 3.3.1.

3.3.3. For alloys containing tin

A portion of the alloy (see table.2) is placed in a beaker with a capacity of 250 cm, add 0.2 g of sodium chloride and dissolved in 20 cmof nitric acid diluted 1:1 with heating and further analysis are as indicated in claim 3.3.1.

3.3.4. Construction of calibration curve

In eight glasses with a capacity of 250 cmadministered 0; 1,0; 2,0; 4,0; 8,0; 12,0; 16,0 20.0 cmstandard solution B is added to 10 cmof nitric acid, diluted 1:1, add water up to 75 cmand further analysis are as indicated in claim 3.3.1.

The found values of optical densities and corresponding contents of phosphorus build a calibration curve.

3.4. Processing of the results

3.4.1. Mass fraction of phosphorus in percent is calculated by the formula

,

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

 — the weight of the portion,

3.4.2. The absolute discrepancies in the results of parallel measurements ( — convergence) must not exceed the permissible values given in table.1.

(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.1.

3.4.2, 3.4.3. (Changed edition, Rev. N 2, 3).

3.4.4. 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 under GOST 8.315, or by a method of additives in accordance with GOST 25086.

(Changed edition, Rev. N 3).