GOST 11739.23-99

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  ГОСТ 11739.23-99

GOST 11739.23−99 Alloys aluminum casting and wrought. Methods for determination of zirconium

GOST 11739.23−99

Group B59

INTERSTATE STANDARD

ALLOYS ALUMINIUM CAST AND WROUGHT

Methods for determination of zirconium

Aluminium casting and wrought alloys. Methods for determination of zirconium

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 11739.23−99 introduced directly as state standard of the Russian Federation from September 1, 2000

4 REPLACE GOST 11739.23−82

1 Scope

This standard establishes photometric (at a mass fraction of zirconium from 0.002% to 0.25% and from 0.02% to 0.5%) and titrimetric (with a mass fraction of zirconium from 0.5% to 3.0%) methods for determination of zirconium in aluminum casting and wrought alloys.

2 Normative references

The present standard features references to the following standards:

GOST 83−79 Sodium carbonate. Specifications

GOST 3118−77 hydrochloric Acid. Specifications

GOST 3759−75 Aluminium chloride 6-water. Specifications

GOST 3760−79 Ammonia water. Specifications

GOST 3773−72 Ammonium chloride. Specifications

GOST 4204−77 sulfuric Acid. Specifications

GOST 4461−77 nitric Acid. Specifications

GOST 5456−79 of Hydroxylamine hydrochloride. Specifications

GOST 10484−78 hydrofluoric Acid. Specifications

GOST 10652−73 Reagents. Salt is the disodium Ethylenediamine-N, N, N', N'-tetraoxane acid 2-water (Trilon B). Specifications

GOST 22867−77 Ammonium nitrate. 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 Photometric method for the determination of zirconium, arsenazo III

4.1 the essence of the method

The method is based on dissolving the samples in hydrochloric acid, the formation of the hydrochloric acid is 6 mol/DMcolored blue complex of zirconium with arsenazo III and measurement of optical density at a wavelength 665−670 nm.

4.2 Equipment, reagents and solutions

Muffle furnace with thermostatic control.

Spectrophotometer.

a pH meter.

Hydrochloric acid according to GOST 3118 density of 1.19 g/cm, mortar 1:1 and 1:3.

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

Hydrofluoric acid according to GOST 10484.

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

Ammonium nitrate according to GOST 22867, a solution of 200 g/DM.

Ammonium chloride according to GOST 3773.

Ammonia water according to GOST 3760.

Sodium carbonate according to GOST 83.

Aluminium chloride 6-water according to GOST 3759.

Solution aluminium 25 g/DM: 45 g aluminum chloride are dissolved in 150 cmof hydrochloric acid of 1:1, transfer the solution into a volumetric flask with a capacity of 200 cm, is poured a solution of hydrochloric acid 1:1 to the mark and mix.

Arsenazo, III, a solution of 2.5 g/DM: 0.25 g of reagent was dissolved with mild heating in 90 cmof water containing 0.3 g of sodium carbonate, pH set (4,0±0,1) using a pH meter and a solution of hydrochloric acid 1:3, transfer the solution into a measuring flask with a capacity of 100 cm, cooled, made up to the mark with water and mix. The solution is suitable for use for 6 months.

The quality of each new batch arsenazo III check for this set the optimal wavelength of a complex of zirconium with arsenazo III, removing a part of the spectrum of light absorption from 630 to 700 nm every 5 nm, for the point of calibration curve appropriate to the content of zirconium 0,00002 g (see 4.3.4). If satisfactory as the reagent, the maximum absorption of the complex is at a wavelength 665−670 nm and shall be not less than half unit of optical density.

Zirconium oxychloride 8-water.

Standard solutions of zirconium.

Solution a: 1,767 g of 8-aqueous zirconium oxychloride were placed in a glass with a capacity of 250 cm, 150 cm pour thehydrochloric acid solution of 1:3, boiled for 5 min, cooled, transferred to a volumetric flask with a capacity of 500 cm, is poured a solution of hydrochloric acid 1:3 to the mark and mix.

1 cmof the solution contains 0.001 g of zirconium.

Set the mass concentration of a standard solution of zirconium , g/cm: aliquot part of the solution 23 cmwas placed in a beaker with a capacity of 300 cm, a flow of 70−80 cmof water, add 1 g of ammonium chloride, heated to 60−70 °C and added dropwise, with stirring, ammonia until the appearance of noticeable odor.

Solution and the precipitate was heated to boiling, incubated 20 minutes in a warm place at a temperature of 40−50 °C, then filtered through the filter medium density («white ribbon»). The filter cake is washed five times with ammonium nitrate solution. The filter with precipitate was placed in a brought to constant weight at a temperature of (1000±10) °C platinum crucible, dried, carefully incinerated and calcined in a muffle furnace at a temperature of (1000±10) °C for 1 h, cooled in a desiccator and weighed.

The mass concentration of a standard solution of zirconium , g/cm, is calculated by the formula

, (1)

where is the mass of the sediment after ignition, g;

0,7403 — the ratio of zirconium dioxide to zirconium;

 — the volume of a standard solution of zirconium taken for the establishment of the mass concentration, cm.

Solution B: 10 cmstandard solution And mass concentration calculated by the formula (1), transferred with a pipette into a measuring flask with a capacity of 100 cm, is poured a solution of hydrochloric acid 1:3 to the mark and mix.

1 cmof the solution contains 0.0001 g of zirconium.

Solution: 4 cmstandard solution B is transferred with a pipette into a measuring flask with a capacity of 100 cm, is poured a solution of hydrochloric acid 1:1 to the mark and mix.

1 cmof the solution contains 0,000004 g of zirconium.

The solution are applied

IEM.

4.3 analysis

4.3.1 the sample the sample weight in accordance with table 1 was placed in a conical flask with a capacity of 250 cm, 30 cm, pour thehydrochloric acid solution of 1:1 and dissolving the sample first at room temperature, then with moderate heat. The solution is carefully evaporated to the appearance of wet salts, cooled, poured 100 cmof hydrochloric acid of 1:1 and dissolved salts at a moderate heat.


Table 1

4.3.1.1 When the mass fraction of silicon is less than 4% solution was transferred to volumetric flask with a capacity of 200 cm, is poured a solution of hydrochloric acid 1:1 to the mark and mix. If the solution is not transparent, it is filtered through the filter medium density (white ribbon) in a dry flask.

4.3.1.2 When the mass fraction of silicon in excess of 4% solution and the precipitate was filtered in a volumetric flask with a capacity of 200 cmthrough the filter medium density («white ribbon»), washed the filter 2−3 times with hydrochloric acid 1:1 in portions of 10 cm, collecting the filtrate in the same flask (stock solution).

The filter with precipitate was placed in a platinum crucible, dried, incinerated, preventing ignition, and calcined at 500−600 °C for 2−3 min. After cooling in the 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 evaporated to dryness, cooled, poured to the dry residue in the crucible 10 cmof hydrochloric acid 1:1 and dissolved under moderate heating. The solution was then cooled, if necessary, filtered through a small, dense filter («blue ribbon») and added to the main solution in a volumetric flask with a capacity of 200 cm, is poured a solution of hydrochloric acid 1:1 to the mark and mix.

4.3.2 Aliquot part of the solution in accordance with table 1 was placed in a volumetric flask with a capacity of 50 cm, poured from a pipette a solution of hydrochloric acid 1:1 to a volume of 20 cm, a solution of aluminum in accordance with table 1, 1 cmof the solution, arsenazo III, add a solution of hydrochloric acid 1:1 to the mark and mix.

4.3.3 Optical density of the solution measured after 5 min at a wavelength of 665 nm in a cuvette with a layer thickness of 10 mm, covered with a lid; it is possible to use cuvettes with a layer thickness of 20 mm. Solution comparison the solution serves as the reference experiment in 4.3.4.

The mass of zirconium is determined by the calibration schedule.

4.3.4 Construction of calibration curve

In ten volumetric flasks with a capacity of 50 cmeach poured in 10 cmof hydrochloric acid 1:1, 2 cmof a solution of aluminium in nine of them measure 0,25; 0,5; 1,0; 1,5; 2,0; 2,5; 3,0; 4,0; 5,0 cmstandard solution, which corresponds to 0,000001; 0,000002; 0,000004; 0,000006; 0,000008; 0,00001; 0,000012; 0,000016; 0,00002 g zirconium, and then continue on 4.3.2 and 4.3.3.

Solution not containing zirconium, serves as a solution control experience in construction of calibration curve.

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

4.4 Processing of results

4.4.1 Mass fraction of Zirconia , %, is calculated by the formula

, (2)

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

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

4.4.2 discrepancies in the results must not exceed the values given in table 2.


Table 2

Percentage

5 Photometric method for the determination of zirconium kylinalove orange

5.1 the essence of the method

The method is based on dissolving the samples in hydrochloric acid, the formation in solution hydrochloric acid 1 mol/DMpainted in orange-red color complex of zirconium with selenology orange and measuring the optical density of the solution at a wavelength of 536 nm.

5.2 the Instrument, reagents and solutions

Oven muffle.

Spectrophotometer or photoelectrocolorimeter.

Hydrochloric acid according to GOST 3118 density of 1.19 g/cm, solutions 1:1, 1:3, 1:99 and 2.5 mol/DM.

Hydrofluoric acid according to GOST 10484.

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

Ammonium nitrate according to GOST 22867, a solution of 200 g/DM.

Ammonium chloride according to GOST 3773.

Ammonia water according to GOST 3760.

Hydroxylamine hydrochloride according to GOST 5456, solution 100 g/DM.

Aluminium chloride 6-water according to GOST 3759.

Solution aluminium 25 g/DM: 45 g aluminum chloride are dissolved in 150 cmof water, pour 15 cmof a hydrochloric acid solution 1:1, transfer the solution into a volumetric flask with a capacity of 200 cm, made up to the mark with water and mix.

Selenology orange, solution 2 g/lfreshly prepared.

Salt is the disodium Ethylenediamine-N, N, N', N'-tetraoxane acid 20-water (Trilon B) according to GOST 10652, solution 0,025 mol/DM.

Zirconium oxychloride 8-water.

Standard solutions A and B 4.2.

Standard solution: 5 cmstandard solution B is transferred with a pipette into a measuring flask with a capacity of 100 cm, made up with hydrochloric acid of 2.5 mol/DMup to the mark and mix.

1 cmof the solution contains 0,000005 g of zirconium.

The solution In preparing to PR

the changes.

5.3 analysis

5.3.1 Sample the sample in accordance with table 3 was placed in a conical flask with a capacity of 250 cm, poured in small portions 30 cmof a hydrochloric acid solution of 1:1 and dissolving the sample first at room temperature, then with moderate heat. The solution is carefully evaporated to the appearance of damp salt, and poured 70 cmof a hydrochloric acid solution of 1:1 and dissolved salts when heated.


Table 3

5.3.1.1 If the mass fraction of silicon is less than 4% solution was transferred to volumetric flask with a capacity of 200 cm, flow 10 cmof hydrochloric acid 1:1, made up to the mark with water and mix. If the solution is not transparent, it is filtered through the filter medium density (white ribbon) in a dry flask.

5.3.1.2 When the mass fraction of silicon in excess of 4% solution and the precipitate was filtered in a volumetric flask with a capacity of 200 cmthrough the filter medium density («white ribbon»), washed the filter 2−3 times with hot hydrochloric acid 1:99 in portions of 10 cm, collecting the filtrate in the same flask (stock solution).

The filter with precipitate was placed in a platinum crucible, dried, incinerated, preventing ignition, and calcined at 500−600 °C for 2−3 min. After cooling in the 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 evaporated to dryness, cooled, poured to the dry residue in the crucible 10 cmof hydrochloric acid 1:1 and dissolved under moderate heating. The solution was then cooled, if necessary, filtered through a small, dense filter («blue ribbon») and added to the main solution in a volumetric flask with a capacity of 200 cm, made up to the mark with water and mix.

5.3.2 Aliquot part of the solution in accordance with table 3 is placed in a volumetric flask with a capacity of 50 cm, pour 2 cmof a solution of hydroxylamine hydrochloride, incubated 5 min, in accordance with table 3 pour a solution of hydrochloric acid of 2.5 mol/DMsolution of aluminum, 2 cmof mortar kylinalove orange, made up to the mark with water and mix.

5.3.3 Optical density of the solution is measured after 15 min at a wavelength of 536 nm in a cuvette with a layer thickness of 30 mm.

As a solution comparison of using a compensating solution — relevant aliquot part of the test solution with all reagents, in which before adding the orange kylinalove administered 0.5 cmof the solution Trilon B.

The mass of zirconium is determined by the calibration schedule.

5.3.4 Construction of calibration curve

Nine volumetric flasks with a capacity of 50 cmeach poured from the burette 20; 19; 18; 17; 16; 15; 14; 13; 12 cmof a hydrochloric acid solution 2.5 mol/DM, 2 cmof a solution of aluminum and, since the second flask, measure out 1,0; 2,0; 3,0; 4,0; 5,0; 6,0; 7,0; 8,0 cmstandard solution, which corresponds to 0,000005; 0,00001; 0,000015; 0,00002; 0,000025; 0,00003; 0,000035; 0,00004 g of zirconium pour 2 cmkylinalove orange, made up to the mark with water, mix and then continue on 5.3.3.

Solution not containing zirconium, serves as a solution control experience in construction of calibration curve.

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

5.4 processing of the results

5.4.1 Mass fraction of Zirconia , %, is calculated by the formula

, (3)

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

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

5.4.2 the Divergence of results should not exceed the values given in table 4.


Table 4

Percentage

6 Titrimetric method for the determination of zirconium

6.1 the essence of the method

The method is based on dissolving the sample in hydrochloric acid and titration of zirconium in hydrochloric acid solution 1 mol/DMwith Trilon B with indicator kylinalove orange.

The interfering influence of iron III can be eliminated by introduction of hydroxylamine hydrochloride.

6.2 Apparatus, reagents and solutions

Oven muffle.

Hydrochloric acid according to GOST 3118 density of 1.19 g/cm, mortar 1:1 and 1:3.

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

Ammonium nitrate according to GOST 22867, a solution of 200 g/DM.

Ammonium chloride according to GOST 3773.

Ammonia water according to GOST 3760.

Hydroxylamine hydrochloride according to GOST 5456, solution 100 g/DM.

Selenology orange, solution 2 g/lfreshly prepared.

Zirconium oxychloride 8-water.

Standard solution of zirconium 4.2.

Salt is the disodium Ethylenediamine-N, N, N', N'-tetraoxane acid 2-water (Trilon B) according to GOST 10652, a solution of 0.0125 mol/DM: 4,653 g Trilon B dissolved in 200 cmof water, filtered through a medium density filter (white ribbon) in a measuring flask with volume capacity of 1000 cm, made up to the mark with water and mix.

To establish the mass concentration of Trilon B in the zirconium into the conical flask with a capacity of 250 cmis placed 10 cmstandard solution zirconium And poured 20 cmof a hydrochloric acid solution of 1:1, 100 cmof hot water and heated to boiling, poured 25 cmof a solution of hydrochloride of hydroxylamine, four drops kylinalove orange and titrated the Zirconia with a solution of Trilon B to change the Magenta color of the solution yellow.

Mass concentration of Trilon B in the zirconium , g/cm, is calculated by the formula

, (4)

where mass concentration of a standard solution of zirconium, g/cm;

 — the volume of a standard solution zirconium, cm;

 — volume of solution Trilon B, cm.

6.3 analysis

A portion of sample weighing 0.5 g is placed in a conical flask with a capacity of 250 cm, poured in small portions 40 cmof a hydrochloric acid solution of 1:1 and dissolving the sample first at room temperature, then with moderate heat. To the solution add 8−10 drops of nitric acid and gently evaporated to the appearance of wet salts, cooled, poured 25 cmof a solution of hydrochloric acid 1:1, dissolved salts when heated, pour 100 cmof hot water and heated to boiling. To the hot solution poured 25 cmof a solution of hydrochloride of hydroxylamine, four drops kylinalove orange and titrated the Zirconia with a solution of Trilon B to change the Magenta color of the solution yellow.

In the case of pale crimson color after reaching the equivalence point the solution is heated to boiling and titrated until a stable yellow color.

6.4 Processing of results

6.4.1 Mass fraction of Zirconia , %, is calculated by the formula

, (5)

where  — volume of solution Trilon B, used for titration, cm;

 — established mass concentration of the solution Trilon B in the zirconium g/cm;

 — weight of sample, g.

6.4.2 Divergence of results should not exceed the values given in table 5.


Table 5

Percentage