GOST 11739.15-99

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  ГОСТ 11739.15-99

GOST 11739.15−99 Alloys aluminum casting and wrought. Method for the determination of sodium

GOST 11739.15−99

Group B59

INTERSTATE STANDARD

ALLOYS ALUMINIUM CAST AND WROUGHT

Method for the determination of sodium

Aluminium casting and wrought alloys. Method for determination of sodium

ISS 77.120.10
AXTU 1709

Date of introduction 2000−09−01

Preface

1 DEVELOPED by JSC «Russian Institute of light alloys» (JSC VILS), the Interstate technical Committee for standardization MTK 297 «Materials and semi-finished products of light alloys"

INTRODUCED by Gosstandart of Russia

2 ADOPTED by the Interstate Council for standardization, Metrology and certification (Protocol No. 16−99 dated 8 October 1999)

The adoption voted:

3 Resolution of the State Committee of the Russian Federation for standardization and Metrology dated February 18, 2000 N 41-St inter-state standard GOST 11739.15−99 introduced directly as state standard of the Russian Federation from September 1, 2000

4 REPLACE GOST 11739.15−82

1 Scope

This standard sets flame photometric method for the determination of sodium in aluminum casting and wrought alloys with the mass fraction of sodium from from 0.0002% to 0.05%.

2 Normative references

The present standard features references to the following standards:

GOST 3118−77 hydrochloric Acid. Specifications

GOST 4038−79 Nickel (II) chloride 6-water. Specifications

GOST 4204−77 sulfuric Acid. Specifications

GOST 4233−77 Sodium chloride. Specifications

GOST 4461−77 nitric Acid. Specifications

GOST 5457−75 Acetylene, dissolved and gaseous. Specifications

GOST 10484−78 hydrofluoric Acid. Specifications

GOST 10929−76 Hydrogen peroxide. Specifications

GOST 11069−74 Aluminium primary. Stamps*
__________________
* On the territory of the Russian GOST 11069−2001, here and hereafter. — Note the manufacturer’s database.

GOST 14261−77 hydrochloric Acid of high purity. Specifications

GOST 25086−87 non-ferrous metals and their alloys. General requirements for methods of analysis

3 General requirements

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

3.1.1 the result of the analysis be the arithmetic mean of results of two parallel measurements.

4 the essence of the method

The method is based on dissolving the sample in hydrochloric acid and subsequent measurement of the intensity of emission of sodium at 589 nm in a flame acetylene-air.

5 Apparatus, reagents and solutions

The fiery photometer or spectrophotometer atomic absorption operating in the mode of emission.

Drying oven with thermostat.

Quartz apparatus for distillation.

Quartz flasks.

Water, double-distilled in quartz apparatus (redistilled for the preparation of solutions and analysis); stored in a plastic container.

Acetylene according to GOST 5457, cleaned with sulfuric acid.

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

Hydrochloric acid according to GOST 14261 or GOST 3118, distilled in a quartz apparatus, a density of 1.19 g/cm, mortar 1:1 and 1:99.

Hydrofluoric acid according to GOST 10484.

Nitric acid according to GOST 4461 density of 1,35−1,40 g/cm.

Hydrogen peroxide according to GOST 10929.

Nickel (II) chloride 6-water according to GOST 4038, a solution of 2 g/DM.

Aluminium GOST 11069 brand А999.

A solution of aluminum 50 g/DM: 25 g of aluminum was placed in a quartz flask with a capacity of 600 cm, add 50 cmof water and then small portions of 400 cmof a hydrochloric acid solution of 1:1, dissolved by heating, adding 1 cmof a solution of Nickel chloride (II). 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. The solution was stored in a plastic container.

Sodium chloride according to GOST 4233.

Standard solutions of sodium.

Solution a: 2,5420 g of sodium chloride, previously dried at a temperature of 105−110 °C, is dissolved in 50 cmof water, transfer the solution into a measuring flask with volume capacity of 1000 cm, made up to the mark with water and mix.

1 cmof the solution contains 0.001 g of sodium.

Solution B: 10 cmstandard solution And 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 0.0001 g of sodium.

Solution: 10 cmstandard solution B is 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 0,00001 g of sodium.

Solutions B and C were prepared immediately before use.

6 analysis

6.1 the sample the sample weighing 1 g is placed in a quartz conical flask with a capacity of 250 cm, equipped with reverse refrigerator, quartz, add portions 20 cmof a hydrochloric acid solution of 1:1 and heated moderately until the end of the dissolution. Add 3−5 drops of hydrogen peroxide and boiled for 3 min. 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.

6.2 When the mass fraction of silicon in excess of 1% after completion of dissolution in 6.1 the solution was 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(core solution).

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 five drops of sulfuric acid, 5 cmhydrofluoric acid and drop by drop nitric acid (approximately 1 cm) to obtain a transparent solution. The solution was then evaporated to dryness, after cooling, the residue moistened with 2−3 cmof water and dissolved in 5 cmof a hydrochloric acid solution 1:1 with moderate heating.

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

.

6.3 Solution of the reference experiment is prepared in accordance with 6.1 and 6.2 in at least two parallel definitions with all the reagents used in the analysis.

6.4 Construction of calibration graphs

6.4.1 When the mass fraction of sodium from from 0.0002% to 0.001%

In seven volumetric flasks with a capacity of 100 cmeach placed at 20 cmof a solution of aluminium, in five of them measure 0,2; 0,4; 0,6; 0,8; 1,0 cmstandard solution, which corresponds to the 0,000002; 0,000004; 0,000006; 0,000008; 0,00001 g of sodium.

6.4.2 When the mass fraction of sodium in excess of 0.001% to 0.005%

In seven volumetric flasks with a capacity of 100 cmeach placed at 20 cmof a solution of aluminium, in five of them measure 1,0; 2,0; 3,0; 4,0; 5,0 cmstandard solution, which corresponds to the 0.00001; 0,00002; 0,00003; 0,00004; of 0.00005 g of sodium.

6.4.3 When the mass fraction of sodium in excess of 0.005% to 0.05%

Eight volumetric flasks with a capacity of 100 cmeach placed at 20 cmof a solution of aluminum in six of them measure 0,5; 1,0; 2,0; 3,0; 4,0; 5,0 cmstandard solution B, which corresponds to 0,00005; 0,0001; 0,0002; 0,0003; 0,0004; 0,0005 g of sodium.

6.4.4 the Solutions in flasks obtained according to 6.4.1−6.4.3, made up to the mark with water and mix.

Solutions that do not contain sodium, are the solutions in the reference experiment when constructing the calibration graphs.

6.5 the sample Solution, the solutions in the reference experiment and the solutions for constructing the calibration graphs is sprayed into the flame of acetylene-air and measure the intensity of emission of sodium at 589 nm.

According to the obtained values of radiation intensity and corresponding mass concentrations of sodium build calibration curve.

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

7 Processing of results

7.1 Mass fraction of sodium , %, is calculated by the formula

, (1)

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

 — mass concentration of sodium 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

.

7.2 discrepancies in the results must not exceed the values given in table 1.


Table 1

Percentage