GOST 1652.4-77

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  ГОСТ 1652.4-77

GOST 1652.4−77 Alloys copper-zinc. Methods for determination of manganese (with Amendments No. 1, 2, 3, 4)

GOST 1652.4−77

Group B59

STATE STANDARD OF THE USSR

ALLOYS COPPER-ZINC

Methods for determination of manganese

Copper-zinc alloys. Methods for the determination of manganese

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 (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 1652.4−71

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. REVISED (June 1991) with Changes No. 1, 2, 3*, approved in October 1981 and November 1987, October 1989, December 1992 (IUS 12−81, 2−88, 2−90, 3−93)
_____________
* Probably a mistake of the original. Should read: «with the Changes N 1, 2, 3, 4». — Note the manufacturer’s database.

This standard specifies the titrimetric method for the determination of manganese (at a mass proportion of manganese from 0.5 to 7%), a photometric method for the determination of manganese (at a mass fraction of manganese from 0.01 to 4%) and atomic absorption method for the determination of manganese (at a mass fraction of manganese from 0.01 to 5%) in copper-zinc alloys according to GOST 15527, GOST and GOST 17711 1020.

(Changed edition, Rev. N 3, 4).

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. PERSULPHATE TITRIMETRIC METHOD FOR THE DETERMINATION OF MANGANESE

2.1. The essence of the method

The method is based on the oxidation of divalent manganese to pneumococcal neccersarily ammonium in an acidic medium in the presence of a catalyst of silver nitrate and the titration of pneumococcal of manganese with a solution of sodium servational to a bleaching solution or salt Mora establishment with potentiometric endpoint titration or visual with phenylanthranilic acid as indicator.

2.2. Apparatus, reagents and solutions

Potentiometer type LPM-60M.

The platinum electrode ETPL-01M.

The electrode attoreny (prepared from silver chloride electrode EVL-1M, not the former in use, filling it with saturated solution of potassium nitrate).

Potassium nitrate according to GOST 4217, saturated solution.

Potassium permanganate according to GOST 20490, 0.01 mol/DMsolution.

Hydrofluoric acid according to GOST 10484.

Sulfuric acid according to GOST 4204, diluted 1:1 and 1:9.

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

Orthophosphoric acid according to GOST 14897.

Ammonium neccersarily according to GOST 20478, a solution of 200 g/DM.

Silver nitrate according to GOST 1277, a solution of 10 g/DM.

Sodium carbonate crystal according to GOST 84 and 0.2% solution.

A mixture of acids, is prepared as follows: 525 cmof water is poured carefully in small portions with stirring, 100 cmof concentrated sulfuric acid. The solution was cooled, poured 250 cmof nitric acid and 125 cmof phosphoric acid.

Manganese GOST 6008 brand Мр00.

Solution manganese standard; prepared as follows: 0.1 g of manganese dissolved in 10 cmof nitric acid, diluted 1:1, and boil to remove oxides of nitrogen. The solution was cooled, transferred to a volumetric flask with a capacity of 100 cm, made up to the mark with water and mix.

1 cmof the solution contains 0.001 g of manganese.

Chernovetskiy sodium (sodium thiosulfate) according to GOST 27068, 0,0025 mol/DMsolution; prepared as follows: chernovetskogo of 1.30 g of sodium are dissolved in 1 DMsvejeprokipachenna and chilled water. To stabilize the mass concentration of the solution add 0.05 g of sodium carbonate. The mass concentration of sodium thiosulfate establish a standard solution of manganese.

Phenylanthranilic acid, a solution of 4 g/DM, is prepared as follows: 0.4 g phenylanthranilic acid are dissolved in 100 cmof warm sodium carbonate solution. The solution was filtered and stored for not more than 10 days.

Salt Mora (double sulphate salt of divalent iron and ammonium) according to GOST 4208, 0,0025 mol/DMsolution; prepared as follows: 19,608 g of Mohr salt dissolved in 100 cmof sulphuric acid, diluted 1:9, and the same acid diluted to 1 DM

2.2.1. The installation of the mass concentration of the sodium thiosulfate

5 cmstandard solution of manganese is placed in a conical flask with a capacity of 250 cm, flow 20 cmof the mixture of acids and boil for 5 minutes to remove oxides of nitrogen. Then pour the 80 cmwater and 15 cmof a solution of silver nitrate and 20 cmof a solution of ammonium naternicola. The solution is heated for 15−20 minutes at low boil until complete destruction of the excess naternicola ammonium, as evidenced by the cessation of allocations of small bubbles of oxygen. Painted purple solution is rapidly cooled and titrated manganese acid 0,0025 mol/DMsolution of sodium thiosulfate until the disappearance of the pink color.

The mass concentration of sodium thiosulfate (), expressed in grams of manganese per 1 cmof a solution, calculated by the formula

,

where 0,005 — weight manganese, taken for titration, g;

 — the amount of sodium thiosulfate, spent on titration, sm.

2.2.2. The installation of the mass concentration of salt solution Mora for potentiometric titration

It is titrated with the sample solution, see p.2.3.2, add 10 cmof 0.01 mol/DMsolution of potassium permanganate and again potentiometric titrated with a solution of salt Mora to jump in the potential.

2.2.3. The installation of the mass concentration of salt solution Mora for visual titration with acid phenylantranilic

In a conical flask with a capacity of 250 cmis placed 10 cmsulfuric acid, diluted 1:1, 10 cmof phosphoric acid, 100 CCof water and 10 cmof 0.01 mol/DMsolution of potassium permanganate.

The cooled mixture titrated with a solution of salt Mora before moving the pink color of the solution to slightly pink, then add 4−5 drops of solution phenylanthranilic acid and dotirovat before moving crimson color in light yellow.

Mass concentration solution of salt Mora (), expressed in grams of manganese per 1 cmof a solution, calculated by the formula

,

where 0,0005494 — weight manganese, corresponding to 1 cmof 0.01 mol/DMsolution of potassium permanganate, g;

 — the volume of 0.01 mol/DMof potassium permanganate solution taken for titration, cm;

 — the volume of salt solution Mora spent on titration, sm

.

2.2, 2.2.1−2.2.3. (Changed edition, Rev. N 4).

2.3. Analysis

2.3.1. During the titration with sodium thiosulfate

2.3.1.1. For alloys containing not more than 0.2% silicon

A portion of the alloy depending on the content of manganese (tab.1) is placed in a conical flask with a capacity of 250 cm, and dissolved in 20 cmof a mixture of acids when heated.

Table 1

The solution was boiled for 5 min to remove the oxides of nitrogen, then pour 80 cmof water, 10−15 cmof solution of nitrate of silver, 20 cmsolution naternicola of ammonia, heat the solution until boiling and slightly boiled for 15−20 min to complete the destruction of excess naternicola ammonium (until the termination of allocation of small bubbles of oxygen) and the solution was titrated as described in section 2.3.1.2.

2.3.1.2. For alloys with a mass fraction of more than 0.2% silicon

A portion of the alloy depending on the manganese content (see table.1) is placed in a platinum Cup and dissolved by heating in 10 cmof nitric acid, diluted 1:1, and 2−3 cmhydrofluoric acid. After complete dissolution of the alloy poured 10 cmof sulphuric acid diluted 1:1, and evaporated until a white smoke of sulfuric acid. The residue is cooled, poured 30 cmof water, heated to dissolve the salts and the solution transferred to a conical flask with a capacity of 250 cm, rinsing the Cup 20 cmof water. Then pour 10 cmof phosphoric acid, 15 cmof a solution of silver nitrate and 20 cmof a solution of ammonium naternicola. The compound is weakly boiled for 15−20 min for complete destruction of excess naternicola ammonium (until the termination of allocation of small bubbles of oxygen).

Painted purple solution is rapidly cooled and titrated manganese acid 0,0025 mol/DMsolution of sodium thiosulfate until the disappearance of the pink color.

2.3.1.1, 2.3.1.2. (Changed edition, Rev. N 4).

2.3.2. When potentiometric titration with a solution of salt Mora

The weight of the alloy (see table.1) is placed in a beaker with a capacity of 250 cm, or platinum Cup. Dissolution of the sample and oxidation of manganese is carried out as indicated in the claims.2.3.1.1 and 2.3.1.2.

2.3.2.1. The hot solution is painted in violet color, quickly potentiometric titrated with a solution of salt Mora.

2.3.3. By visual titration with a solution of salt Mora with phenylantranilic acid

Dissolution of the sample and oxidation of manganese is carried out as indicated in the claims.2.3.1.1 and 2.3.1.2. The solution after decomposition of the excess ammonium naternicola rapidly cooled, diluted with water to a volume of 100−150 cmand titrated 0.005 mol/DMsolution of salt Mora to slightly pink coloring, then add 4−5 drops of solution phenylanthranilic acid and continue to titrate until the colour from crimson to light yellow.

(Changed edition, Rev. N 4).

2.4. Processing of the results

2.4.1. Mass fraction of manganese () in percent is calculated by the formula

,

where is the volume of sodium thiosulfate (or salt Mora), spent on titration, sm;

 — mass concentration of the sodium thiosulfate (or salt Mora) for manganese, g/cm;

 — the weight of the portion,

(Changed edition, Rev. N 4).

2.4.2. 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, 4).

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.

2.4.4. 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 supplements method, or comparison of the results obtained by another method in accordance with GOST 25086.

2.4.3, 2.4.4. (Changed edition, Rev. N 4).

2.4.4.1, 2.4.4.2. (Deleted, Rev. N 4).

3. PERIODITY PHOTOMETRIC METHOD FOR THE DETERMINATION OF MANGANESE

3.1. The essence of the method

The method is based on the oxidation of divalent manganese to pneumococcal in an acidic medium with potassium periodate and measurement of the resulting purple color of permanganate ion.

3.2. Apparatus, reagents and solutions

Photoelectrocolorimeter or spectrophotometer.

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

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

Hydrofluoric acid according to GOST 10484.

Orthophosphoric acid according to GOST 6552.

Boric acid according to GOST 9656, saturated solution.

60 g boric acid dissolve in 1 DMof hot water and after dissolution was cooled to room temperature.

The mixture of acids to dissolve; prepared as follows: 100 cmhydrofluoric acid are added to 900 cmsaturated solution of boric acid and mix well (solution stored in a plastic container).

Cognately potassium.

Sodium atomistically according to GOST 4197, a solution of 50 g/DM.

Copper marks M1, M0 or M00.

Manganese GOST 6008 brand Мр00.

Solution manganese standard; prepared as follows: 0.1 g of manganese dissolved in 10 cmof nitric acid, diluted 1:1, and boil to remove oxides of nitrogen. The solution was cooled, transferred to a volumetric flask with a capacity of 1 DM, made up to the mark with water and mix well.

1 cmof the solution contains 0.0001 g of manganese.

Water without reducing substances; distilled water acidified with sulfuric acid (10 cmsulfuric acid to 1 liter of water), boil, add a few crystals of potassium jednolitego and boil for 10 minutes, then water cooled.

3.3. Analysis

3.3.1. For alloys containing tin and silicon

A portion of the alloy, the mass of which depends on the mass fraction of manganese (table.2), placed in a beaker with a capacity of 250 cm, add 15 cmof the mixture of acids, 15 cmwater and 15 cmof concentrated nitric acid and 5 cmof orthophosphoric acid, initially dissolved without heating, and then by heating and removing the nitrous oxide by boiling. For the mass concentration of manganese in excess of 0.2% of the cooled solution is transferred to a volumetric flask with a capacity of 100 cm, made up to the mark with water and mix.

Table 2A

To aliquote part of the solution, according to table.2A, was added 0.3 g of potassium jednolitego. The solution was cooled, was added 0.3 g of potassium jednolitego and boil for 5 min.

Then the solution continued to heat for 20 min in a water bath at 80−90 °C., then cooled, transferred to a volumetric flask with a capacity of 100 cm, made up to the mark with water and mix. Measure the optical density of the solution in a cuvette with a layer thickness of 1 cm on a photoelectrocolorimeter with a green optical filter at a wavelength of 540 nm or on a spectrophotometer at a wavelength of 528 nm. As a solution comparison, using part of the solution of the same samples in which pneumococcal manganese reduced to divalent by the addition dropwise of a solution of sodium nitrate before bleaching.

3.3.2. For alloys not containing tin and silicon

A portion of the alloy (see p.3.3.1) is placed in a beaker with a capacity of 250 cm, add 30 cmwater and 15 cmof concentrated nitric acid and 5 cmof phosphoric acid. First, the dissolution of lead without heating, and then to complete dissolution of the sample solution is heated to 80−90 °C. the analysis was carried out as specified in section 3.3.1.

3.3.3. Construction of calibration curve

Seven of cups with a capacity of 250 cmis placed 1 g (or 0.1 g) of copper, add 15 cmof the mixture of acids, at 15 cmof water, 15 cmof concentrated nitric acid and 5 cmof phosphoric acid and dissolved without heating, and then by heating. Then remove the oxides of nitrogen by boiling. Enter 0; 1,0; 2,0; 4,0; 6,0; 8,0 and 10.0 cmof a standard solution of manganese, add 0.3 g of potassium jednolitego and further analysis are as indicated in claim 3.3.1.

3.4. Processing of the results

3.4.1. Mass fraction of manganese () in percent is calculated by the formula

,

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

 — the weight of the portion of alloy,

3.5. The absolute discrepancies in the results of parallel measurements ( — convergence) must not exceed the permissible values given in table.3.

Table 3

3.6. 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.3.

3.5, 3.6. (Changed edition, Rev. N 2, 4).

3.7. 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.

3.7. (Changed edition, Rev. N 4).

3.7.1−3.7.3. (Deleted, Rev. N 4).

4. ATOMIC ABSORPTION METHOD FOR THE DETERMINATION OF MANGANESE

4.1.The essence of the method

The method is based on dissolving the sample in a mixture of hydrochloric and nitric acids or in the presence of silicon in hydrofluoric and nitric acids and measuring the nuclear absorption of manganese in the flame acetylene-air, using light with a wavelength of 279.5 nm or 403,1.

4.2. Apparatus, reagents and solutions

The atomic absorption spectrometer.

Lamp with hollow cathode for manganese.

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

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

A mixture of hydrochloric and nitric acids in the ratio 1:1.

Hydrofluoric acid according to GOST 10484.

Chloric acid, diluted 1:1.

Manganese GOST 6008.

Standard manganese solution: 0.1 g of manganese dissolved in 15 cmof nitric acid, boiling removes oxides of nitrogen, the solution was cooled and transferred into a measuring flask with volume capacity of 1000 cm, made up to the mark with water and mix.

1 cmof the solution contains 0.1 mg of manganese.

4.3. Analysis

4.3.1. For alloys containing silicon up to 0.05%, a sample of alloy weighing 0.5 g were placed in a glass with a capacity of 250 cm, add 20 cmof a mixture of acids and dissolved by heating. After dissolution, the solution was cooled, transferred to a volumetric flask with a capacity of 100 or 250 cm, made up to the mark with water and mix. For the mass concentration of manganese in excess of 0.1% of selected aliquot part according to the table.4, in a volumetric flask with a capacity of 100 cm, add 20 cmof a mixture of acids, made up to the mark with water, mix and measure the atomic absorption of manganese 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 light with a wavelength 297,5 or 403,1 nm when the mass fraction of manganese over 1%.

Table 4

(Changed edition, Rev. N 3).

4.3.2. For alloys containing silicon in excess of 0.05%, a sample of alloy weighing 0.5 g is placed in a platinum Cup and dissolved in 3 cmhydrofluoric acid and 10 cmof nitric acid, diluted 1:1 added in parts. After dissolution, add 10 cmof perchloric acid and evaporated to release the white smoke of perchloric acid. After cooling, add 30 cmof water, the residue is dissolved and the solution transferred to a volumetric flask with a capacity of 100 or 250 cm, add 20 cmof a mixture of acids, made up to the mark with water and mix. Then do depending on the manganese content, as specified in clause 4.3.1.

4.3.3. Construction of calibration curve

In seven of the eight volumetric flasks with a capacity of 100 cmplaced 0,5; 1,0; 2,0; 4,0; 6,0; 8,0 and 10.0 cmof a standard solution of manganese, which corresponds to 0,05; 0,1; 0,2; 0,4; 0,6; 0,8 and 1.0 mg of manganese. All flasks is poured 20 cmof a mixture of acids, fluids topped up to the mark with water, mix and measure the atomic absorption of manganese immediately before and after the measurement of absorption in the analyzed sample solution.

According to the obtained values build the calibration graph.

4.4. Processing of the results

4.4.1. Mass fraction of manganese () in percent is calculated by the formula

,

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

the concentration of manganese 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;

 — the weight of the portion of the sample corresponding to part of the solution, g

.

4.4.2. The absolute discrepancies in the results of parallel measurements ( — convergence) must not exceed the permissible values given in table.3.

(Changed edition, Rev. N 2, 4).

4.4.3. 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.3.

(Changed edition, Rev. N 2, 4).

4.4.4. 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.

4.4.4. (Changed edition, Rev. N 4).

4.4.4.1−4.4.4.3. (Deleted, Rev. N 4).