GOST 11739.4-90

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  ГОСТ 11739.4-90

GOST 11739.4−90 Alloys aluminium cast and wrought. Methods for determination of bismuth

GOST 11739.4−90

Group B59

STATE STANDARD OF THE USSR

ALLOYS ALUMINIUM CAST AND WROUGHT

Methods for determination of bismuth

Aluminium casting and wrought alloys.
Methods for determination of bismuth

AXTU 1709

Valid from 01.07.91
before 01.07.96*
________________________________
* Expiration removed
Protocol 5−94 N Interstate Council
for standardization, Metrology and certification
(IUS N 11/12, 1994). — Note the manufacturer’s database.

INFORMATION DATA

1. DEVELOPED AND INTRODUCED by the Ministry of aviation industry of the USSR

DEVELOPERS:

V. G. Davydov, doctor of engineering. Sciences; V. A. Moshkin, PhD. tech. Sciences; G. I. Friedman, PhD. tech. Sciences; L. A. Tenyakova; M. N. Gorlova, PhD. chem. Sciences; O. L. Sikorska, PhD. chem. Sciences; L. V. Antonenko

2. APPROVED AND put INTO EFFECT by Decision of the USSR State Committee on management of quality and standards from 28.06.90 N 1961

3. REPLACE GOST 11739.4−78

4. The frequency of inspection — 5 years

5. REFERENCE NORMATIVE AND TECHNICAL DOCUMENTS

This standard specifies the photometric (with a mass fraction of bismuth from 0.005 to 0.8%) and atomic absorption (at a mass fraction of bismuth from 0.05 to 1.0%) methods for determining bismuth.

1. GENERAL REQUIREMENTS

1.1. General requirements for methods of analysis GOST 25086 with the Supplement.

1.1.1. For the results analysis be the arithmetic mean of results of two parallel measurements.

2. THE PHOTOMETRIC METHOD FOR THE DETERMINATION OF BISMUTH

2.1. The essence of the method

The method is based on dissolving the sample in a mixture of sulfuric and nitric acids or sodium hydroxide solution, the formation of the orange-yellow complex of bismuth with potassium iodide and subsequent measurement of optical density at a wavelength of 465 nm.

2.2. Apparatus, reagents and solutions

Spectrophotometer or photoelectrocolorimeter.

Sulfuric acid according to GOST 4204, density 1.84 g/cmand a solution of 1:3.

Nitric acid according to GOST 4461, density 1,35−1,40 g/cmand a solution of 1:1.

Sodium hydroxide according to GOST 4328, a solution of 400 g/DM. The solution is prepared and stored in a plastic container.

Sodium atomistically according to GOST 4197, solution 20 g/DM.

A mixture of acids N 1: to 100 cmof water carefully in portions with stirring, poured 200 cmof sulfuric acid, cooled to room temperature, poured to 200 cmof nitric acid and stirred.

A mixture of acids N 2: 400 cmof sulfuric acid solution poured 50 cmof nitric acid and stirred.

Mix N 3: up to 400 cmof sulfuric acid solution poured 50 cmof nitric acid and stirred. Solution before use, is heated to approximately 80 °C and poured 2cmof a solution of sodium attestatio.

Iron chloride according to GOST 4147, a solution of 10 g/DM.

Potassium iodide according to GOST 4232, a freshly prepared solution of 200 g/DM.

Thiourea according to GOST 6344, solution 100 g/DM.

Bismuth GOST 10928* brand ВИ0000 or ВИ000.
_______________
* On the territory of the Russian Federation GOST 10928−90, here and hereafter. — Note the manufacturer’s database.

A standard solution of bismuth: 0.1 g of bismuth were placed in a glass with a capacity of 100 cm, 30 cm, pour thenitric acid, cover with watch glass and dissolve with a moderate heat. After dissolution of the sample solution was cooled to room temperature, transferred to a measuring flask with volume capacity of 1000 cm, made up to the mark with water and mix.

1 cmof the solution contains 0.0001 g of bismuth.

Aluminium GOST 11069* brand А999.
_______________
* On the territory of the Russian GOST 11069−2001, here and hereafter. — Note the manufacturer’s database.

Adsorbent (materiana paper): 100 g of crushed filters (red ribbon) is placed in a beaker with a capacity of 500 cm, 300 cm pouredhot water and stirred with a stirrer to obtain od

neous mass.

2.3. Analysis

2.3.1. A portion of the sample mass according to table.1 dissolve one of the following ways.

Table 1

2.3.1.1. When the mass fraction of silicon is less than 0.5% of the weighed sample is placed in a conical flask with a capacity of 250 cm, 25 cm pour themixture of acids of N 1. After the cessation of violent reaction solution is heated to dissolve the sample, add 30 cmof water and boil the solution for 1−2 min If the solution is not transparent, it is filtered through the filter medium density («white ribbon») with an adsorbent in a volumetric flask with a capacity of 100 cm, rinsing the flask and rinsing the filter 2−3 times with hot water in portions of 10 cmbelow the volume of the filtrate was not more than 80 cm, and cool the solution to room temperature.

When the mass fraction of bismuth less than 0.08% spend fotometricheskie solution from the entire sample in a volumetric flask with a capacity of 100 cm.

When the mass fraction of bismuth of more than 0.08% solution topped to the mark with water, mix and continue according to claim 2.3.2

.

2.3.1.2. When the mass fraction of silicon of more than 0.5% of the weighed samples were placed in a glass made of PTFE or glassy carbon with a capacity of 200 cm, pour 1 cmof solution of ferric chloride if its mass fraction in the sample is less than 0.2%, then pour 5−7 cmof water and with constant cooling in small portions — 50 cmof sodium hydroxide solution. After termination of the reaction the beaker was heated until complete dissolution of the sample and with moderate heating, avoiding splashing, evaporated to 15−20 cm. The presence in the solution of the characteristic Muti-gray color indicates the presence of undissolved silica. In this case, the heating should be continued until a clear solution. After cooling in a glass, carefully poured 180−200 cmof water and heated to dissolve the salts.

The solution was filtered through a filter medium density («white ribbon») with the adsorbent. The filter cake was washed 8−10 times with hot water and dissolved in 45 cma hot mixture of acids of N 2 over a Cup or flask with a capacity of 250−300 cm. If the sample contains more than 0.5% of manganese, the residue is dissolved in 45 cmhot mix N 3. The filter was washed 6 times with hot water in portions of 20 cm, collecting the washings in the same beaker.

The filtrate and washings evaporated to a volume of 70−80 cm, cooled to room temperature, transferred to a volumetric flask with a capacity of 100 cm.

When the mass fraction of bismuth less than 0.08% spend fotomaterialy solution for the whole sample in a volumetric flask with a capacity of 100 cm.

When the mass fraction of bismuth of more than 0.08% solution topped to the mark with water and traveling.

sivut.

2.3.2 the sample solution or aliquote part of the solution (see table.1) in a volumetric flask with a capacity of 100 cmpour a solution of sulfuric acid (see table.1) 5 cmof a solution of thiourea, 10 cmof a solution of potassium iodide, made up to the mark with water and mix.

2.3.3. Optical density of the solution is measured after 20 min at a wavelength of 465 nm in a cuvette with a layer thickness according to table.1.

Solution comparison is the solution of the reference experiment, which is prepared according to claim.2.3.1.1 or 2.3.1.2 and 2.3.2 all used in the analysis reagents.

Mass fraction of bismuth is calculated according to the calibration schedule.

2.3.4. Construction of calibration graphs

2.3.4.1. When the mass fraction of silicon is less than 0.5% in six of the seven volumetric flasks with a capacity of 100 cmmeasured 0,5; 1,0; 2,0; 3,0; 4,0; 5,0 cmstandard solution of bismuth, which corresponds to 0,00005; 0,0001; 0,0002; 0,0003; 0,0004; 0,0005 g of bismuth flow at 30 cmof sulfuric acid solution and then continue on PP.2.3.2, 2.3.3.

2.3.4.2. When the mass fraction of silicon of more than 0.5% in seven glasses of PTFE or glassy carbon with a capacity of 200 cmis placed hitch aluminum weighing 0.5 g, in six of them measure 0,5; 1,0; 2,0; 3,0; 4,0; 5,0 cmstandard solution of bismuth, which corresponds to 0,00005; 0,0001; 0,0002; 0,0003; 0,0004; 0,0005 g of bismuth, and then continue according to claim 2.3.1.2, fotometriya solution of PP.2.3.2 and 2.3.3 in a volumetric flask with a capacity of 100 cmfrom the entire sample.

Comparison solutions are solutions that do not contain bismuth.

According to the obtained values of optical density of the solutions and their corresponding masses of bismuth build the calibration graph.

2.4. Processing of the results

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

, (1)

where is the mass of bismuth in the sample solution found by the calibration schedule g;

 — the weight of the portion of the sample or the weight of the portion of the sample in aliquote part of the solution,

2.4.2. Discrepancies in the results must not exceed the values given in table.2.

Table 2

3. ATOMIC ABSORPTION METHOD FOR THE DETERMINATION OF BISMUTH

3.1. The essence of the method

The method is based on dissolving the samples in hydrochloric acid in the presence of hydrogen peroxide and subsequent measurement of the atomic absorption of bismuth at a wavelength of 223,1 nm in the flame acetylene-air.

3.2. Apparatus, reagents and solutions

Spectrophotometer of atomic absorption with a radiation source for bismuth.

Acetylene according to GOST 5457.

Hydrochloric acid according to GOST 3118, density of 1.19 g/cm, mortar 1:1 and 1:99.

Nitric acid according to GOST 4461, density 1,35−1,40 g/cmand a solution of 1:3.

Sulfuric acid according to GOST 4204, density 1.84 g/cm.

Hydrofluoric acid according to GOST 10484.

Hydrogen peroxide according to GOST 10929.

Nickel chloride according to GOST 4038, a solution of 1 g/DM.

Aluminium GOST 11069 brand А999 (with a mass fraction of bismuth is less than 0.001%).

A solution of aluminum 20 g/DM: 10 g of aluminum is placed in a beaker with capacity of 500 cm, add 50 cmof water, then small portions of 300 cmof a hydrochloric acid solution (1:1) and dissolve with a moderate heat, adding 1 cmof solution of chloride Nickel. The solution was cooled to room temperature, transferred to a volumetric flask with a capacity of 500 cm, made up to the mark with water and mix.

Bismuth GOST 10928 brand ВИ0000 or ВИ000.

Standard solutions of bismuth.

Solution a: 0.5 g of bismuth were placed in a glass with a capacity of 300 cm, 100 cm pour thenitric acid solution and dissolved under moderate heating. The solution was boiled to remove oxides of nitrogen, cooled to room temperature, transferred to a volumetric flask with a capacity of 500 cm, made up to the mark with water and mix.

1 cmof the solution contains 0.001 g of bismuth.

Solution B: 50 cmsolution And transferred to a volumetric flask with a capacity of 100 cm, pour 5 cmof a solution of nitric acid, made up to the mark with water and mix.

1 cmof a solution contains 0.0005 g of bismuth.

Solution: 10 cmsolution And transferred to a volumetric flask with a capacity of 100 cm, pour 5 cmof a solution of nitric acid, made up to the mark with water and mix; prepare before use.

1 cmof the solution contains 0

, 0001 g of bismuth.

3.3. Analysis

3.3.1. A portion of sample weighing 0.5 g is placed in a conical flask with a capacity of 250 cm, pour approximately 10 cmof water and then small portions of 25 cmof a solution of hydrochloric acid (1:1). The beaker cover watch glass, heat to completely dissolve the sample, add 3−5 drops of hydrogen peroxide and boil the solution for 3 min.

Watch glass and walls of the flask rinsed with water. The solution was cooled to room temperature, transferred to a volumetric flask with a capacity of 100 cm, made up to the mark with water and mix.

3.3.2. When the mass fraction of silicon is less than 1% solution, if it is not transparent, was filtered through a dry filter medium density (white ribbon) in a beaker, discarding the first portions of the filtrate.

3.3.3. When the mass fraction of silicon in excess of 1% after completion of dissolution according to claim 3.3.1 solution is filtered through a filter medium density (white ribbon) in a volumetric flask with a capacity of 100 cm. The filter cake was washed 3−4 times with hot hydrochloric acid 1:99 in portions of 10 cm(primary filtrate).

The filter with precipitate was placed in a platinum crucible, dried, incinerated, preventing ignition, and calcined at 500−600 °C for 3 min. After cooling the content of crucible add four drops of sulphuric acid, 5 cmhydrofluoric acid and nitric acid drop by drop until a clear solution. Next, the solution was evaporated to dryness, after cooling, the residue moistened with 2−3 cmof water and dissolve in 2−3 cmof hydrochloric acid (1:1) under heating.

The solution is attached to the main filtrate in a volumetric flask with a capacity of 100 cm, made up to the mark with water and mix.

3.3.4. The solution in the reference experiment is prepared according to PP.3.3.1, 3.3.2 or 3.3.3, using is sample the sample the sample of aluminium.

3.3.5. Construction of calibration graphs

3.3.5.1. When the mass fraction of bismuth from 0.05 to 0.10% in seven volumetric flasks with a capacity of 100 cmpoured in 25 cmof a solution of aluminum in six of them measure 2,5; 3,0; 3,5; 4,0; 4,5; 5,0 cmstandard solution, which corresponds to 0,00025; 0,0003; 0,00035; 0,0004; 0,00045; 0,0005 g of bismuth.

3.3.5.2. When the mass fraction of bismuth from 0.1 to 0.5% in six volumetric flasks with a capacity of 100 cmpoured in 25 cmof a solution of aluminium, in five of them measure 1,0; 2,0; 3,0; 4,0; 5,0 cmstandard solution B, which corresponds to 0,0005; 0,001; 0,0015; 0,002; 0.0025 g of bismuth.

3.3.5.3. When the mass fraction of bismuth, 0.5 to 1% in seven volumetric flasks with a capacity of 100 cmpoured in 25 cmof a solution of aluminum in six of them measure 2,5; 3,0; 3,5; 4,0; 4,5; 5,0 cmstandard solution A, which corresponds to 0,0025; 0,003; 0,0035; 0,004; 0,0045; 0,005 g of bismuth.

3.3.6. The solutions in flasks in PP.3.3.5.1, 3.3.5.2 3.3.5.3 and topped to the mark with water and mix.

3.3.7. The sample solution, solution control experience and solutions to build the calibration curve is sprayed into the flame of acetylene-air and measure the atomic absorption of bismuth at a wavelength of 223,1 nm.

According to the obtained values of atomic absorption and corresponding mass concentrations of bismuth build the calibration graph.

The mass concentration of bismuth in the sample solution and in the solution of control and experience determined by the calibration schedule.

3.4. Processing of the results

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

, (2)

where is the mass concentration of bismuth in the sample solution found by the calibration schedule, g/cm;

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

 — the volume of the sample solution, cm;

 — weight of sample, g

.

3.4.2. Discrepancies in the results must not exceed the values given in table.3.

Table 3