GOST 26473.11-85

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  ГОСТ 26473.11-85

GOST 26473.11−85 Alloys and alloys based on vanadium. Method for the determination of zirconium and aluminium (corrected, with Change No. 1)

GOST 26473.11−85

Group B59

STATE STANDARD OF THE USSR

ALLOYS AND MASTER ALLOYS BASED ON VANADIUM

Method for the determination of zirconium and aluminium

Vanadium base alloys and alloying elements. Method for determination of zirconium and aluminium

AXTU 1709

Valid from 01.07.86
to 01.07.91*
_______________________________
* Expiration removed
by the decree of Gosstandart of the USSR from 14.05.91 N 680
(IUS N 8, 1991). — Note the manufacturer’s database.

DEVELOPED by the Ministry of nonferrous metallurgy of the USSR

PERFORMERS

Yu. A. Karpov, E. G. Nembrini, V. G., Miscreants, V. V. Nedler, V. M. Mikhailov, L. G. Agapova, G. N. Andrianov, A. V. Antonov, V. D. Dozen, M. A. Desyatkova, T. I. Kirillova, L. I. Kirsanov, I. E. Korepin, V. A. Orlova, N. Rasnitsyn, N. Suvorova, N. L. Tomasev, M. W. Schmidt, L. N. Filimonov

INTRODUCED by the Ministry of nonferrous metallurgy of the USSR

Member Of The Board Of A. P. Snurnikov

APPROVED AND put INTO EFFECT by Decision of the USSR State Committee on standards of 25 March 1985 N 752


AMENDED, published in IMS No. 1, 1986

An amendment made by the manufacturer of the database

The Change N 1, approved and put into effect by the Decree of the USSR State Committee on management of quality and standards from 14.05.91 N 677 from 01.01.92

Change No. 1 made by the manufacturer of the database in the text IUS N 8, 1991


This standard specifies the method of chelatometric determination of Zirconia (5 to 25%) and aluminum (from 5 to 30%) in alloys and master alloys based on vanadium, the contents of related components which are shown in table.1.

Table 1

The method is based on the separation of zirconium and aluminium from vanadium and niobium by precipitation with ammonia in presence of hydrogen peroxide, sequential determination of zirconium and aluminium in the same solution by direct chelatometric titration of zirconium in hydrochloric acid solution with indicator kylinalove orange and back titration of excess Trilon B added to bind aluminum, with a solution of zinc salt at a pH of 5.5 with indicator kylinalove orange.

1. GENERAL REQUIREMENTS

1.1. General requirements for methods of analysis GOST 26473.0−85.

2. APPARATUS, REAGENTS AND SOLUTIONS

Muffle furnace with thermostat providing temperatures up to 1100 °C.

Analytical scale.

Libra technical.

Tile electric.

The quartz Cup.

Glasses chemical glass with a capacity of 200, 250 and 500 cm.

Conical flasks with a capacity of 250 cm.

Volumetric flasks with a capacity of 1 DM.

Pipettes with a capacity of 10 and 20 cm,with no divisions.

The obezvolennyh paper filter «white ribbon» or «yellow ribbon».

Funnels, glass, conical.

Crucibles porcelain.

Desiccator with calcium chloride.

Burettes with a capacity of 25 cmwith a scale division of 0.1 cm.

Measuring beakers with a capacity of 25, 100 and 1000 cm.

Paper display «of the Congo».

Universal indicator paper.

Potassium preservatory according to GOST 7172−76.

Sulfuric acid according to GOST 4204−77.

Hydrochloric acid by the GOST 3118−77, diluted 1:5 and 1:1.

Ammonia water according to GOST 3760−79 and diluted 1:1.

Ammonium chloride according to GOST 3773−72, solutions of concentration of 100 and 20 g/DM.

Wash solution: to 1000 cmof solution of ammonium chloride concentration of 20 g/DM, add 2−3 cmof hydrogen peroxide and 2 cmof ammonia.

Hydrogen peroxide according to GOST 10929−76.

Selenology orange solution with a concentration of 1 g/DM.

Zirconium oxychloride.

Standard solution of zirconium containing about 5 mg/cmZirconia: 17,65 g of zirconium oxychloride were placed in a glass with a capacity of 500 cm, 100 cm pouredwater 300 cmof hydrochloric acid diluted 1:1, heated to complete dissolution of the sample. The solution was transferred to volumetric flask with a capacity of 1 DM, adjusted to the mark with water.

The exact mass concentration of the zirconium establish a gravimetric method. To do this in a glass with a capacity of 250 cmpipetted 20 cmstandard solution zirconium, adding 100 cmof water, heated to 50−80 °C and the precipitated zirconium hydroxide with a solution of ammonia. The precipitate was filtered off through the filter of «white ribbon», washed with hot water containing 10 cmof ammonia at 500 cmof water. The filter with precipitate was placed in a porcelain crucible, previously ignited to constant weight, dried, incinerated, and calcined in a muffle furnace for 30 minutes at 1000−1100 °C, then cooled in a desiccator and weighed. The ignition is repeated until constant weight.

Mass concentration () of a standard solution of zirconium, expressed in mg/cm, calculated by the formula

,

where is the mass of the precipitate of Zirconia, mg;

0,7403 — the ratio of Zirconia to zirconium.

Trilon B (disodium salt of Ethylenediamine-N, N, N', N'-tetraoxane acid, 2-water) according to GOST 10652−73, solution concentration of 0.05 mol/DM: 18,61 g Trilon B dissolved in water with heating to 70−80 °C, solution then cooled, filtered in a volumetric flask with a capacity of 1 DMand bring to mark with water.

Trilon B (disodium salt of Ethylenediamine — N, N, N', N'-tetraoxane acid, 2-water) according to GOST 10652−73, solution concentration of 0.025 mol/DM: 9.3 g Trilon B dissolved in water with heating to 70−80 °C, the solution was cooled to room temperature, filtered in a volumetric flask with a capacity of 1 DM, adjusted to the mark with water.

Technical methenamine according to GOST 1381−73.

Zinc, granulated.

Zinc chloride, solution concentration of 0.05 mol/DM: 3,2690 g of zinc metal is placed in a beaker with a capacity of 200 cm, 20−30 cm, moistened withwater and poured in small portions 25 cmhydrochloric acid solution, diluted 1:1, heated to complete dissolution of zinc and is evaporated to wet salts. Salt is dissolved by heating in water, transfer the solution into a volumetric flask with a capacity of 1 DM, adjusted to the mark with water.

(Changed edition, Rev. N

1).

2.1. The installation mass concentration (0.025 mol/l) of Trilon B solution in the zirconium

In a conical flask with a capacity of 250 cmpipetted 10 cmstandard solution zirconium, adding 30 cmof a hydrochloric acid solution, diluted 1:1, 60 cmof water, heated to 60−70 °C, add 2−3 drops of the solution kylinalove orange and titrated with a solution of Trilon B to switch the color of the solution from yellow to crimson. The solution is heated to boiling, add 1 drop of solution kylinalove orange and the appearance of crimson color of the solution is added dropwise another solution of Trilon B to switch the color to yellow.

The mass concentration of the solution Trilon B (), expressed in g/cmof zirconium, calculated by the formula

,

where mass concentration of a standard solution of zirconium, expressed in g/cmzirconium;

10 — the volume of a standard solution of zirconium taken for the titration, cm;

 — volume of solution Trilon B, spent on titration, sm.

2.2. Setting the mixing ratio between the solutions of Trilon B (0.05 mol/DM) and zinc chloride in conical flask with a capacity of 250 cmpipetted 20 cmof a solution of zinc chloride, poured 80 cmof water, neutralized with ammonia to a pH of 3.5−4.0 on the universal indicator paper, add 1.5−2 g of hexamine, 2−3 drops of solution kylinalove orange and titrated with a solution of Trilon B till the transition of color from crimson to yellow.

The ratio () of the volume of the solution Trilon B and zinc chloride is calculated by the formula

,

where 20 is the volume of solution of zinc chloride taken for titration, cm;

 — volume of solution Trilon B, spent on titration, sm.

3. ANALYSIS

A portion of the sample weighing 0.1 g was placed in a quartz Cup, add 3−4 g of persulfate potassium, a few drops of concentrated sulphuric acid and fused in a muffle at 800−900 °C to produce a clear float. The melt was dissolved with heating in a mixture of 20−25 cmof hydrochloric acid diluted 1:5 with 10−15 cmof hydrogen peroxide. The resulting solution was transferred to a conical flask with a capacity of 250 cm, add 20−25 cmof a solution of ammonium chloride concentration of 100 g/l, heated to boiling and carefully add ammonia diluted 1:1, weak to the point of view of smell (pH near 7 on the universal indicator paper) and continue boiling for a few minutes.

Provide sediment to koagulirovat, quickly filter the solution and precipitate through a paper filter of medium density white ribbon and the filter cake washed 6−7 times with hot flushing solution.

The filter with precipitate was placed in a flask in which was conducted the deposition, poured 20 cmof hydrochloric acid diluted 1:1, heated to complete dissolution of the precipitate add 3−5 drops of solution kylinalove orange and titrated the Zirconia with a solution of Trilon B (0,025 mol/DM) until the solution colour from crimson to yellow. The solution is heated to boiling, add 1 drop of solution kylinalove orange and the appearance of crimson color of the solution is added dropwise another solution of Trilon B till the transition of color in yellow ().

To the solution after the definition therein of zirconium is added from burette 25−30 cmof the solution Trilon B (0.05 mol/DM), neutralized with ammonia (about 20 cmammonia) on indicator paper «the Congo» until the transition of color from blue to lilac-pink. The solution is heated and boiled for 10−15 min. after cooling to room temperature, add 1−1. 5 g of hexamine, 3−4 drops of solution kylinalove orange and titrate the excess Trilon B solution zinc until the solution colour from pink to crimson ().

4. PROCESSING OF THE RESULTS

4.1. Mass fraction of zirconium () in percent is calculated by the formula

,

where  — volume of solution Trilon B (0,025 mol/DM) consumed for titration, cm;

 — mass concentration of the solution Trilon B, expressed in g/cmzirconium;

 — the weight of the portion of the sample,

4.2. Mass fraction of aluminium () in percent is calculated according to the formula

,

where  — volume of solution Trilon B (0.05 mol/DM) added to the analyzed solution, cm;

 — the volume of solution of zinc, consumed in the titration of excess Trilon B, cm;

0,001349 — mass concentration of the solution Trilon B, expressed in g/cmof aluminum;

 — the ratio of the volume of the solution Trilon B and zinc chloride;

 — the weight of the portion of the sample, g

.

4.3. The values of permissible differences are listed in table.2.

Table 2

(Changed edition, Rev. N 1).