GOST 9853.2-96

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  ГОСТ 9853.2-96

GOST 9853.2−96 Titan spongy. Method for determination of iron

GOST 9853.2−96

Group B59

INTERSTATE STANDARD

TITANIUM SPONGE

Method for determination of iron

Sponge titanium. Method for determination of iron content

ISS 77.120*
AXTU 1709
_______________
* In the index «National standards» 2007 ACS 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 9853.2−96 introduced directly as state standard of the Russian Federation from July 1, 2000.

4 REPLACE GOST 9853.2−79

1 Scope

This standard sets the photometric method for the determination of iron (at mass fraction of iron from 0.002% to 2.0%) in the spongy titanium according to GOST 17746.

The method is based on formation of colored orange-red complex compound of bivalent iron with phenanthroline or 2,2'-dipyridil in slightly acidic medium in the presence of titanium, held in solution in the form of complex compounds with tartaric acid, followed by determination 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 199−78 Sodium acetate 3-water. Specifications

GOST 5456−79 of Hydroxylamine hydrochloride. Specifications

GOST 5817−77 tartaric Acid. Specifications

GOST 9656−75 boric Acid. Specifications

GOST 10484−78 hydrofluoric Acid. Specifications

GOST 13610−79 carbonyl Iron radio. Specifications

GOST 14261−77 hydrochloric Acid of high purity. Specifications

GOST 17746−96 spongy Titanium. 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 iron determined in two batches.

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

4 measuring instruments and auxiliary devices

Spectrophotometer type SF-46 or photoelectric colorimeter KFK-type or similar instrument.

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

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

Boric acid according to GOST 9656, crystal.

Hydroxylamine hydrochloride (hydroxylamine hydrochloride) according to GOST 5456, solution mass concentration of 100 g/DM.

-phenanthroline sulfate (-fenantrolin sulfate), the solution of the mass concentration of 2.5 g/DM.

2,2'-dipyridyl, solution mass concentration of 0.5 g/DM: 0.05 g of 2,2'-dipyridyl dissolved in 100 cmof water with the addition of 0.5 cmof a hydrochloric acid molar concentration of 0,1 mol/DM.

Sodium acetate (sodium acetate) 3-water according to GOST 199, solution mass concentration of 250 g/DM.

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

Standard samples according to GOST 8.315.

Iron metal restored by the current normative document or the iron carbonyl and radio according to GOST 13610.

Indicator paper Congo according the current normative document.

Standard solutions of iron.

Solution a: 0,100 g of iron dissolved in 30 cmof a hydrochloric acid solution (1:1) under heating. The solution was cooled to room temperature, transferred into a measuring flask with volume capacity of 1000 cm, made up to the mark with water and mix. The solution is usable for 3 months.

1 cmof the solution contains 0.0001 g of iron.

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 iron.

5 procedures for measuring

5.1 administrai pre-Weighed sample weight of 0.5−1.5 g was placed in a polyethylene beaker with a capacity of 100−150 cm, 30 cm, pour thehydrochloric acid solution (1:1), add 1−2 drops of hydrofluoric acid. Beaker cover watch glass or funnel glass and lead dissolution.

After dissolution, the sample is added 1−2 g of boric acid, the solution transferred to a volumetric flask with a capacity according to table 1, made up to the mark with water and mix.


Table 1

Aliquot part of the solution, according to table 1 is transferred to a volumetric flask with a capacity of 100 cm, was diluted to 20 cmof water, pour 3 cmof a solution of hydroxylamine, 5 cmof a solution of tartaric acid. The solution is neutralized by the paper of the Congo with sodium acetate solution until the color of the paper of the Congo from blue to purple, and then poured the excess 1−2 cmof the solution, add 10 cmof solution -fenantrolina (or 10 cmof a solution of 2,2'-dipyridyl), made up to the mark with water and mix.

After 30 min, measure the optical density of the solution at a wavelength of 440 nm (-fenantrolina) or 540 nm (dipyridylium) in a cuvette with a thickness of the absorbing layer is 50 mm. Solution comparison the solution serves as the reference experiment.

Mass fraction of iron in the sample is calculated according to the calibration.

ku.

5.2 Construction of calibration curve

5.2.1 To build the calibration curve in mass fraction of iron from 0.002% to 0.13% in seven of the eight volumetric flasks with a capacity of 100 cmplaced 0,5; 1,0; 1,5; 2,0; 3,0; 4,0; 5,0 cmstandard solution B, which corresponds to 0,000005; 0,00001; 0,000015; 0,00002; 0,00003; 0,00004; 0,00005 g of iron. The eighth solution of the flask is a solution of the reference experiment.

5.2.2 To construct the calibration curve for the mass concentration of iron from 0.13% to 2.0% in six of the seven volumetric flasks with a capacity of 100 cmplaced 0,5; 1,0; 1,5; 2,0; 2,5; 3,0 cmstandard solution A, which corresponds to 0,00005; 0,0001; 0,00015; 0,0002; 0,00025; 0,0003 g of iron. A seventh solution of the flask is a solution of the reference experiment.

The solutions in all flasks is diluted with water to about 20 cm, add 3 cmof a solution of hydroxylamine hydrochloride, 5 cmof a solution of tartaric acid and then act as described in 5.1.

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

6 Processing of measurement results

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

, (1)

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

 — total volume of sample solution, cm;

 — the mass of sample, g;

 — volume aliquote parts of a solution of the sample, cm.

7 the Permissible error of measurement

7.1 the Difference between the two measurements and the results of the analysis (with confidence ) should 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.