GOST 9853.15-96

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  ГОСТ 9853.15-96

GOST 9853.15−96 Titan spongy. Method for the determination of molybdenum

GOST 9853.15−96

Group B59

INTERSTATE STANDARD

TITANIUM SPONGE

Method for the determination of molybdenum

Sponge titanium. Method for determination of molybdenum

ISS 77.120
AXTU 1709

Date of introduction 2000−07−01

Preface

1 DEVELOPED by the Interstate technical Committee for standardization MTK 105, Ukrainian research and design Institute of titanium

SUBMITTED to the State Committee of Ukraine for standardization, Metrology and certification

2 ADOPTED by the Interstate Council for standardization, Metrology and certification (Protocol No. 9 dated April 12, 1996)

The adoption voted:

3 Resolution of the State Committee of the Russian Federation for standardization and Metrology dated 19 October 1999 No. 353-St inter-state standard GOST 9853.15−96 introduced directly as state standard of the Russian Federation from July 1, 2000.

4 INTRODUCED FOR THE FIRST TIME

1 Scope

This standard specifies the extraction-photometric method for the determination of molybdenum (with a mass fraction of from 0.0005% to 0.1%) in the spongy titanium according to GOST 17746.

The method is based on the formation of complex compounds of molybdenum (VI) with ammonium thiocyanate in the presence of a reducing agent is tin dichloride, followed by extraction of the complex with the butyl acetate and measuring the optical density of the extract.

2 Normative references

The present standard features references to the following standards:

GOST 8.315−97 State system for ensuring the uniformity of measurements. The standard samples. The main provisions, the order of development, certification, approval, registration and application

GOST 3118−77 hydrochloric Acid. Specifications

GOST 4204−77 sulfuric Acid. Specifications

GOST 4328−77 Sodium hydroxide. Specifications

GOST 4461−77 nitric Acid. Specifications

GOST 10484−78 hydrofluoric Acid. Specifications

GOST 17746−96 spongy Titanium. Specifications

GOST 22300−76 the ethyl and butyl Esters of acetic acid. Specifications

GOST 23780−96 spongy Titanium. Methods of sampling and sample preparation

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

GOST 27067−86 Ammonium radamisty. Specifications

3 General requirements

3.1 General requirements for methods of analysis GOST 25086.

3.2 Selection and preparation of samples is carried out according to GOST 23780.

3.3 Mass fraction of the element determine in two batches.

3.4 the construction of calibration curve, each calibration point is based on the average of the results of the two measurements.

4 measuring instruments and auxiliary devices

Spectrophotometer type SF-46 or photoelectric colorimeter concentration of type KLF-2, or similar device.

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

Sulfuric acid according to GOST 4204, diluted 1:1, 1:9 and 7:93.

Hydrofluoric acid according to GOST 10484.

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

Sodium hydroxide according to GOST 4328, solution mass concentration of 100 g/DM.

Molybdenum (VI) oxide according to the current normative document.

Butyl acetate (butyl ester of acetic acid) according to GOST 22300.

Ammonium tartrate (ammonium vinocity) according to the current normative document, solution mass concentration of 200 g/DM.

Ammonium thiocyanate (ammonium radamisty) according to GOST 27067, solution mass concentration of 200 g/DM.

Tin dichloride (tin dichloride) 2-water according to the current normative document, solution mass concentration of 400 g/DM.

Standard samples according to GOST 8.315.

The washing liquid: prepare a dilute solution of dichloride of tin in the mass concentration of 400 g/DMwater in the ratio of 1:25.

Standard solutions of molybdenum.

Solution a: 1.5 g of molybdenum oxide (VI) was dissolved in 10 cmof sodium hydroxide solution mass concentration of 100 g/DM. The solution was transferred into a measuring flask with volume capacity of 1000 cm, made up to the mark with a solution of diluted sulfuric acid (7:93).

1 cmof the solution contains 0.001 g of molybdenum (VI).

Solution B: aliquote part 1 cmof solution A is placed in a volumetric flask with a capacity of 100 cm, made up to the mark with water and mix.

1 cmof solution B contains 0,00001 g of molybdenum (VI).

5 procedures for measuring

5.1 a sample weight of 0.5−1.5 g was placed in a conical flask with a capacity of 250 cm, 40 cm pouredhydrochloric acid solution (1:1), 15 cmof sulfuric acid solution (1:1) and add 1−2 drops of hydrofluoric acid. The beaker cover watch glass or funnel and lead dissolving when heated. After complete dissolution of the sample add 1 cmof nitric acid, the solution evaporated to fumes of sulphuric anhydride.

5.1.1 in the determination of the mass fraction of molybdenum from 0.0005% to 0.002% of the evaporated solution in the form of syrup diluted with 30 cmof water, poured 25 cmammonium tartrate, stirred and cooled. Then enter the 5 cmof a solution of ammonium thiocyanate, 5 cmof a solution of dichloride of tin and after 5 minutes the solution transferred to a separatory funnel with a capacity of 300 cm, is diluted with water to a volume of 100 cm, add 10 cmof butyl acetate and shake for 2 minutes After separation of phases the aqueous layer is separated, the extract is poured 25 cmof sulfuric acid solution (1:9), 25 cmwashing liquid and shake for 1 min. the Aqueous phase is separated, the extract was filtered through a layer of cotton wool, poured into a dry test-tube or flask with a glass tube

Oh.

5.1.2 When determining the mass fraction of molybdenum from 0.002% to 0.1% of the evaporated solution in the form of syrup is transferred to a volumetric flask with a capacity of 200 cm, made up to the mark with water and mix. Aliquot part of the solution are selected according to table 1 and proceed as 5.1.1.


Table 1

The optical density of the extract is measured at a wavelength of 490 nm in a cuvette with the thickness of the absorbing layer 10 mm.

As a solution comparison solution is used in the reference experiment.

The mass of molybdenum in the sample is calculated according to the calibration schedule.

5.2 In five of the six tumblers with a capacity of 200 cmis placed 0,5; 1,0; 1,5; 2,0; 2,5 cmstandard solution B, which corresponds to 0,000005; 0,000010; 0,000015; 0,000020; 0,000025 g of molybdenum. Solution the sixth glass is a solution in the reference experiment. The solutions in all beakers was diluted 15 cmof sulfuric acid solution (1:1), add 25 cmof a solution of ammonium tartrate, 5 cmof a solution of ammonium thiocyanate, 5 cmof a solution of dichloride of tin. Then act in accordance with 5.1.1.

According to the obtained values of optical density and corresponding masses of molybdenum to build the calibration graph.

6 Processing of measurement results

Fraction of total mass of molybdenum , %, is calculated by the formula

, (1)

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

 — weight of sample in aliquote part of the solution,

7 the Permissible error of measurement

7.1 the discrepancy between the measurement results and analysis results (at a confidence probability of 0.95) shall not exceed the permissible values given in table 2.


Table 2

Percentage

7.2 accuracy Control of the results of the analysis carried out according to standard sample in accordance with GOST 25086.

Allowed to monitor the accuracy of analysis results by the method of additives in accordance with GOST 25086.

Additives is a standard solution A.

8 qualifications

To perform analysis allowed the analyst qualification not less than 4th level.