GOST 9853.20-96

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  ГОСТ 9853.20-96

GOST 9853.20−96 Titan spongy. Method for the determination of vanadium

GOST 9853.20−96

Group B59

INTERSTATE STANDARD

TITANIUM SPONGE

Method for the determination of vanadium

Sponge titanium. Method for determination of vanadium

ISS 77.120*
AXTU 1709

_________________________________
* In the index «National standards», 2008
OKS 77.120, 77.120.50 — note the manufacturer’s database.

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 interstate standard GOST 9853.20−96 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 vanadium (at the mass fraction of vanadium from 0.002% to 0.5%) in the spongy titanium according to GOST 17746.

The method is based on formation of vanadium (V) is colored greenish-yellow phosphorus-wolframmathematica of heteroalicyclic and subsequent measurement of optical density of the solution.

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 84−76 Sodium carbonate 10-water. Specifications

GOST 4197−74 Sodium atomistically. Specifications

GOST 4199−76 Sodium tetraborate 10-aqueous. Specifications

GOST 4204−77 sulfuric Acid. Specifications

GOST 4217−77 Potassium nitrate. Specifications

GOST 4328−77 Sodium hydroxide. Specifications

GOST 6552−80 orthophosphoric Acid. Specifications

GOST 10484−78 hydrofluoric Acid. Specifications

GOST 10929−76 Hydrogen peroxide. Specifications

GOST 14261−77 hydrochloric Acid of high purity. Specifications

GOST 17746−96 spongy Titanium. Specifications

GOST 18289−78 Sodium volframovich 2 water. Specifications

GOST 18300−87 ethyl rectified technical. Specifications

GOST 20490−75 Potassium permanganate. 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

3 General requirements

3.1 General requirements for the method of analysis according to GOST 25086.

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

3.3 Mass fraction of vanadium is determined in two batches.

4 measuring instruments and auxiliary devices

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

Sulfuric acid according to GOST 4204, 1.84 g/cm, and the solution of the mass concentration of 100 g/DM.

Hydrofluoric acid according to GOST 10484.

Hydrochloric acid according to GOST 14261, diluted 1:1.

Sodium carbonate (sodium carbonate) GOST-84.

Sodium tetraborate (sodium tetraborate) according to GOST 4199.

A mixture of sodium carbonate and sodium tetraborate in the ratio 1:2.

Phosphoric acid according to GOST 6552, diluted 1:2.

Vanadium (V) oxide according to the current normative document.

Hydrogen peroxide according to GOST 10929, solution mass concentration 10 g/DM.

Potassium nitrate (potassium nitrate) GOST 4217.

Potassium permanganate (potassium permanganate) according to GOST 20490, solution mass concentration of 50 g/DM.

Sodium hydroxide according to GOST 4328, solution mass concentration 10 g/DM.

Sodium nitrite (sodium atomistically) according to GOST 4197, solution mass concentration 10 g/DM.

Methyl orange according to the current normative document.

Ethanol (ethyl alcohol) rectified technical GOST 18300.

Sodium tungstate (sodium wolframates) according to GOST 18289, solution mass concentration of 50 g/DM.

Standard samples according to GOST 8.315.

A standard solution of vanadium: 0,1785 g of vanadium oxide (V) was dissolved with heating in 10 cmof sodium hydroxide solution. The solution is neutralized with sulfuric acid mass concentration of 100 g/DMand poured it in excess until yellow color of the solution. The solution is transferred into a measuring flask with volume capacity of 1000 cmand top up with water to the mark.

1 cmstandard solution contains 0.0001 g of vanadium.

5 procedures for measuring

5.1 the sample the sample weight according to table 1 was placed in a platinum Cup No. 6, moisten with water, poured 10 cmof sulphuric acid, 10 cm ofhydrofluoric acid and lead dissolving when heated.


Table 1

After complete dissolution of the sample solution is evaporated to dryness, then re-moisten with a little water and evaporated to dryness. The operation is repeated twice.

The dry residue is fused at a temperature of 1223 K with a mixture of sodium carbonate and sodium tetraborate with addition (at the end of a spatula) of potassium nitrate. The smelt is leached with water under heating. After complete leaching solution add a few drops of ethanol until complete discoloration of the solution and reduction of the manganese present in the sample, and heating was continued for 10 min.

Solution and the precipitate was transferred to a volumetric flask with a capacity of 100 cm, cooled to room temperature, made up to the mark with water, mix and filter through dry filter «white ribbon» in a dry flask.

Aliquoting a portion of the filtrate is placed in a volumetric flask with a capacity of 100 cm, add a few drops of methyl orange and neutralize with hydrochloric acid (1:1) until the pink color of the solution, then add another 4 cmit in excess. Then the solution was added 5 drops of hydrogen peroxide solution and dropwise a solution of potassium permanganate until a stable pink color. The excess of potassium permanganate to destroy the addition of a few drops of a solution of sodium nitrite until complete discoloration of the solution and add 1−2 drops of excess, stirring thoroughly.

The solution is poured into 2cmof solution of phosphoric acid, dilute with water to volume of about 80 cm, add 4 cmof a solution of tungstate of sodium, made up to the mark with water and mix.

After 20 minutes, measure the optical density of the solution at a wavelength of 440 nm in a cuvette with the thickness of the absorbing layer is 50 mm. as a solution comparison solution is used in the reference experiment.

Weight of vanadium calculated according to the calibration schedule.

5.2 For constructing the calibration curve in seven of the eight volumetric flasks with a capacity of 100 cmplaced 0,2; 0,5; 1,0; 2,0; 3,0; 4,0; 5,0 cmstandard solution, which corresponds to 0,00002; 0,00005; 0,0001; 0,0002; 0,0003; 0,0004; 0,0005 g of vanadium. The eighth solution of the flask is a solution of the reference experiment.

The solutions in all flasks is diluted with water to a volume of about 50 cm, neutralized by methyl orange with hydrochloric acid (1:1), give the excess of 4 cmand then do as described in 5.1.

According to the obtained values of optical density and corresponding mass of vanadium build the calibration graph.

6 Processing of measurement results

Mass share of vanadium , %, is calculated by the formula

, (1)

where is the mass of vanadium in the sample solution, g;

 — total volume of sample solution, cm;

 — the mass of sample, g;

 — volume aliquote part of the solution, cm.

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.

8 qualifications

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