GOST 9853.7-96

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  ГОСТ 9853.7-96

GOST 9853.7−96 Titan spongy. Method for the determination of aluminium

GOST 9853.7−96

Group B59

INTERSTATE STANDARD

TITANIUM SPONGE

Method for the determination of aluminium

Sponge titanium. Method for determination of aluminium

ISS 77.120*
AXTU 1709
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* 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 9853.7−96 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 aluminum with a mass fraction of aluminum from 0.005% to 1.0% in the sponge titanium according to GOST 17746.

The method is based on formation of blue coloured complex compound of aluminum with sulfochlorinated With subsequent measurement of optical density of the solution.

Preventing to define the elements previously separated by alkali.

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 61−75 acetic Acid. Specifications

GOST 199−78 Sodium acetate 3-water. Specifications

GOST 4328−77 Sodium hydroxide. Specifications

GOST 11069−74* Aluminium primary. Brand
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* On the territory of the Russian GOST 11069−2001, here and hereafter. — Note the manufacturer’s database.

GOST 14261−77 hydrochloric Acid of high purity. Specifications

GOST 17746−96 spongy Titanium. Specifications

GOST 18300−87 ethyl rectified technical. 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 aluminium is determined by two batches.

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 14261, diluted 1:1, and the solution molar concentration of 4 mol/DM.

Aluminum metal according to the current normative document or GOST 11069.

Acetic acid according to GOST 61, a solution of a molar concentration of 2 mol/DM.

Sodium hydroxide according to GOST 4328, solution mass concentration of 200 g/DM.

Sodium acetate (sodium acetate) 3-water according to GOST 199.

Methenamine according to the current normative document, solution mass concentration of 200 g/DM.

Sulfochlorides With under the current regulatory instrument, the solution of the mass concentration of 1 g/DM.

Ethanol (ethyl alcohol) according to GOST 18300.

Phenolphthalein, according to existing normative document, an alcoholic solution of the mass concentration of 1 g/DM.

Indicator paper Congo according the current normative document.

Filter paper fat-free «yellow ribbon» according to the current normative document.

Buffer solution with a pH of 6.2 and 6.3: 250 grams of sodium acetate dissolved in 500 cmof water, add 30−40 cmof acetic acid, add water to 1000 cmand mixed.

Standard samples according to GOST 8.315.

Standard solutions of aluminium.

Solution a: 0.1 g of aluminum metal are dissolved in 20 cmof a hydrochloric acid solution (1:1). The solution was cooled, transferred to a measuring flask with volume capacity of 1000 cm, made up to the mark with water and mix.

1 cmof the solution contains 0.0001 g of aluminum.

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, cook before use.

1 cmof solution B has the 0.00001 g of aluminum.

5 procedures for measuring

5.1 the sample the sample weight of 0.5−1.0 g was placed in a conical flask with a capacity of 250 cm, 70 cm pour thehydrochloric acid solution (1:1), beaker cover watch glass or funnel glass and lead dissolution under heating, maintaining the volume by about 50 cmby the addition of the same solution of hydrochloric acid.

After complete dissolution of the sample dropwise adding nitric acid to the disappearance of the violet color of the solution and boiled for 3−5 min. the Solution was cooled to room temperature, transferred to a volumetric flask with a capacity of 100 cm, made up to the mark with water and mix.

Aliquot part of the solution is 25 cmis placed in a conical flask with a capacity of 250 cm, neutralized with sodium hydroxide solution on the indicator paper Congo to the red paper and add 10 cmof excess. The solution was boiled for 10−20 minutes, cool to room temperature, transferred to a volumetric flask with a capacity of 100 cm, made up to the mark with water and mix. The solution was filtered through a filter of «yellow ribbon» into the conical flask with a capacity of 100 cm, discarding first portion of filtrate.

Aliquoting a portion of the filtrate 5−50 cmis placed in a volumetric flask with a capacity of 100 cm, add one drop of phenolphthalein, and neutralize with hydrochloric acid (4 mol/DM) until the disappearance of color of the indicator and add 0.5 cmof acid solution in excess.

Rinse the throat of the flask with water and neutralized paper of the Congo with a solution of hexamine. Then the solution is poured 10 cmof buffer solution, add water to a volume of approximately 80 cmand injected 2 cmof a solution of sulfochloride C. the Solution is kept for 15−20 min to develop the colour complex compounds, then pour 3 cmof a solution of hydrochloric acid (4 mol/DM), made up to the mark with water and mix.

Optical density of the solution is measured at a wavelength of 670 nm with thickness of the absorbing layer is 50 mm. Solution comparison is the solution of the control

professional experience.

5.2 For constructing the calibration curve in seven of the eight volumetric flasks with a capacity of 100 cmplaced 0,5; 1,0; 2,0; 3,0; 4,0; 5,0; 6,0 cmstandard solution B, which corresponds to 0,000005; 0,00001; 0,00002; 0,00003; 0,00004; 0,00005; 0,00006 g of aluminum. The eighth solution of the flask is a solution of the reference experiment.

All flasks are poured by 0.5 cmof a solution of hydrochloric acid (4 mol/DM) indicator paper Congo neutralized with a solution of hexamine (red paper Congo). Then do as specified in 5.1.

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

6 Processing of measurement results

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

, (1)

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

 — total volume of sample solution, cm;

 — the volume of the first dilution of the sample, cm;

 — the mass of sample, g;

 — volume aliquots of the General solution of the sample, cm;

 — aliquotes volume of the first dilution of the sample, 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 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 are standard solutions A or B.

8 qualifications

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