GOST 9853.9-96

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  ГОСТ 9853.9-96

GOST 9853.9−96 Titan spongy. Method for determination of silicon

GOST 9853.9−96

Group B59

INTERSTATE STANDARD

TITANIUM SPONGE

Method for determination of silicon

Sponge titanium. Method for determination of silicon

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 inter-state standard GOST 9853.9−96 introduced directly as state standard of the Russian Federation from July 1, 2000.

4 INTRODUCED FOR THE FIRST TIME

1 Scope

This standard sets the photometric method for the determination of silicon (with a mass fraction of silicon of from 0.005% to 0.12%) in the spongy titanium according to GOST 17746.

The method is based on formation of blue coloured restored criminalizing complex compounds with 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 83−79 Sodium carbonate. Specifications

GOST 195−77 Sodium sanitarily. Specifications

GOST 3765−78 Ammonium molybdate. Specifications

GOST 5817−77 tartaric Acid. Specifications

GOST 9428−73 Silicon (IV) oxide. Specifications

GOST 9656−75 boric Acid. Specifications

GOST 10484−78 hydrofluoric Acid. Specifications

GOST 17746−96 spongy Titanium. 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 silicon determined by two batches.

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

4 measuring instruments and auxiliary devices

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

Tartaric acid according to GOST 5817, solution mass concentration of 200 g/DM.

Boric acid according to GOST 9656, solution mass concentration of 40 g/DM.

Hydrofluoric acid according to GOST 10484, diluted 3:1.

Ammonium molybdate (ammonium molybdate) according to GOST 3765, recrystallized, solution mass concentration of 50 g/DM, stored in a plastic container.

Ascorbic acid according to the State Pharmacopoeia.

Sodium carbonate (sodium carbonate) GOST-83.

Potassium permanganate (potassium permanganate) according to GOST 20490, solution mass concentration of 30 g/DM.

Sodium sulfite (sodium sanitarily) anhydrous GOST 195.

Titanium sponge grade TG-100 GOST 17746.

1-amino-2-naphthol-4-sulfonic acid according to the current normative document.

Silicon dioxide according to GOST 9428, pre-calcined to constant weight at a temperature of 1273 K.

Standard samples according to GOST 8.315.

Recovery solution: 30 g of ascorbic acid or sodium bisulfite, 1 g of sodium sulfite and 0.5 g of 1-amino-2-naphthol-4-sulfonic acid are dissolved in 175 cmof water and slowly heated to a temperature of (323±5) K. the Solution was then cooled, top up with water to 200 cmand filtered; prepared prior to use.

Standard solutions of silicon.

Solution a: 0.21 g of silica fused in a platinum crucible with 5 g of sodium carbide at temperatures (1223±20) K for 30 min and the Melt is dissolved in water by heating in a platinum Cup. The solution was cooled to room temperature, filtered into a measuring flask with volume capacity of 1000 cm, made up to the mark with water and mix; best to use within 3 months.

1 cmof the solution contains 0.0001 gram of silicon.

The solution was stored in a plastic container with a tight-fitting plastic lid.

Solution B: 10 cmsolution And placed in a volumetric flask with a capacity of 100 cm, made up to the mark with water and mix; prepare before use.

1 cmof solution B contains 0,00001 g of silicon.

Solution: 50 cmsolution And placed in a volumetric flask with a capacity of 100 cm, made up to the mark with water and mix; prepare before use.

1 cmof the solution contains of 0.00005 g of silicon.

5 procedures for measuring

5.1 the sample the sample weight of 0,5 g (with a mass fraction of silicon of from 0.005% to 0.02%) and a weight of 0.2 g (with a mass fraction of silicon in excess of 0.02% to 0.12%) was placed in a polyethylene vessel with a capacity of 250 cm, pour the 40 cmwater, 5 cmhydrofluoric acid, cover with plastic cap and tighten. The vessel was placed in a crystallizer with water having a temperature of (355±5) K, and allowed to stand for about 30−40 min until complete dissolution of the sample.

After complete dissolution of the sample solution is poured into 100 cmof boric acid, 50 cmof water and dropwise added a solution of potassium permanganate until a stable pink color and 5 drops in excess. The vessel put in a water bath for 90 min for determination of the deposition of the titanium solution and the precipitate was periodically stirred.

The solution with precipitate was cooled in cold running water to a temperature of (298±2) K, then poured 10 cmof ammonium molybdate solution, mix and leave to stand for 10 minutes Then add 5 cmof a solution of tartaric acid and immediately from burette 3 cmrecovery solution, stirred and allowed to stand for 25 min.

The solution was transferred to a volumetric flask with a capacity of 250 cm, made up to the mark with water, mixed, filtered through dense dry filter «blue ribbon» in a dry conical flask with a capacity of 100 cm. Optical density of the solution is measured at a wavelength of 670 nm in a cuvette with the thickness of the absorbing layer is 50 mm with a mass fraction of silicon of from 0.005% to 0.02% and 10 mm at a mass fraction of silicon in excess of 0.02% to 0.12%.

Solution comparison is water.

In parallel with the sample analysis spend control experience. Optical density of the solution in the reference experiment is measured relative to the water and subtracted from the optical density of the sample solution.

Mass fraction of silicon is calculated according to the calibration graph

the IR.

5.2 When the mass fraction of silicon of from 0.005% to 0.02% in six polyethylene containers with polyethylene screw-top tubes with a capacity of 250 cmis placed 0.5 g of sponge titanium with a mass fraction of silicon is less than 0.005%.

In five of the six plastic vessels add 2,0; 4,0; 6,0; 8,0; 10,0 cmstandard solution B, which corresponds to 0,00002; 0,00004; of 0.00006; 0,00008; 0,00010 g of silicon. All the vessels poured in 40 cmof water 5 cmhydrofluoric acid, tightly closed and screwed down the plastic tubes and then do as described in 5.1.

The solution of the sixth vessel is a solution of titanium.

When the mass fraction of silicon in excess of 0.02% to 0.12% in seven plastic vessels with a capacity of 250 cmis placed 0.2 g of sponge titanium with silicon content less than 0.005%.

In six of the seven plastic vessels added 0,8; 1,0; 2,0; 3,0; 4,0; 5,0 cmstandard solution, which corresponds to 0,00004; 0,00005; 0,00010; 0,00015; 0,00020; 0,00025 g silicon. All the vessels poured in 40 cmof water 5 cm inhydrofluoric acid and then act as described in 5.1.

The solution of the seventh vessel is a solution of titanium.

Optical density of the solution measured against water.

According to the obtained values of optical density of solutions of titanium with additives of a standard solution silicon, minus the optical density of the solution of titanium, and the respective masses of the silicon to build the calibration graph.

6 Processing of measurement results

Mass fraction of silicon, %, is calculated by the formula

, (1)

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

 — the weight of the portion,

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 values given in table 1.


Table 1

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 B.

8 qualifications

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