GOST 9853.10-96

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  ГОСТ 9853.10-96

GOST 9853.10−96 Titan spongy. Method of determination of niobium and tantalum

GOST 9853.10−96

Group B59

INTERSTATE STANDARD

TITANIUM SPONGE

Method of determination of niobium and tantalum

Sponge titanium. Method for determination of niobium and tantalum

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 9853.10−96 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 niobium (for the mass concentration of niobium from 0.002% to 0.01%) and extraction-photometric method for the determination of tantalum (with a mass fraction of tantalum 0.001% to 0.005%) in the spongy titanium according to GOST 17746.

The method is based on the separation of niobium and tantalum from titanium and related impurities the two-time deposition of niobium and tantalum tannin in hydrochloric acid medium, and then fusing the precipitate with potassium pyrosulphate, education in the presence of tartaric acid is colored red complex compounds of niobium with linformation-2 with subsequent measurement of optical density of the solution.

Tantalum is determined by extraction with benzene complex compound of tantalum with crystal violet 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 2603−79 Acetone. Specifications

GOST 4204−77 sulfuric Acid. Specifications

GOST 4461−77 nitric Acid. Specifications

GOST 4463−76 Sodium fluoride. Specifications

GOST 5712−78 Ammonium oxalate 1-aqueous. Specifications

GOST 5817−77 tartaric Acid. Specifications

GOST 5955−75 Benzene. Specifications

GOST 7172−76 Potassium preservatory

GOST 10484−78 hydrofluoric Acid. Specifications

GOST 10652−73 Salt is the disodium Ethylenediamine-N, N, N', N'-tetraoxane acid 2-water (Trilon B)

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 niobium and tantalum is determined by two batches.

4 measuring instruments and auxiliary devices

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

Hydrochloric acid according to GOST 14261, diluted 1:1, 1:4, 1:9 and 1:49.

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

Sulfuric acid according to GOST 4204, 1.84 g/cm.

Hydrofluoric acid according to GOST 10484.

Ascorbic acid in the State Pharmacopeia X.

Tartaric acid according to GOST 5817, solution mass concentrations of 200 and 40 g/DM.

Tannin in the State Pharmacopeia X, the solution of the mass concentrations of 30 and 10 g/DM, the latter is prepared by dissolving the tannin in 1000 cmof the solution of hydrochloric acid (1:9).

Pyrosulphate potassium (potassium preservatory) according to GOST 7172.

Sodium fluoride (sodium fluoride) according to GOST 4463, solution mass concentration of 50 g/DM.

Benzene according to GOST 5955.

Ammonium gidroksila monohydrate (ammonium oxalate) according to GOST 5712, solution mass concentration of 40 g/DM.

Linformation-2 according to the current normative document, solution mass concentration of 1 g/DM.

Acetone according to GOST 2603.

Crystal violet according to the current normative document, solution mass concentration of 2 g/DM.

Filters obestochennye red ribbon and white ribbon according to the current normative document.

Ethylenediamine-N, N, N', N'-tetraoxane acid disodium salt dihydrate (Trilon B) according to GOST 10652, a solution of molar concentration of 0.025 mol/DM.

State standard samples according to GOST 8.315.

Standard solutions of niobium.

Solution a: 0,3575 g of niobium oxide (V) alloy with 7 g of persulfate potassium in a platinum crucible at a temperature (793±25) K. the smelt is dissolved in 100 cmof solution of tartaric acid mass concentration of 200 g/DM, is transferred into a volumetric flask with a capacity of 500 cm, made up to the mark with water and mix. Unfit for use within one month.

1 cmof the solution contains 0.0005 g of niobium.

Solution B: 2 cmof solution A is placed in a volumetric flask with a capacity of 100 cm, is poured the solution of tartaric acid mass concentration of 40 g/DMup to the mark and mix. Prepare before use.

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

Standard solutions of tantalum.

Solution a: 0,1526 g of the oxide of tantalum (V) fused with a 5−6 g persulfate potassium in a platinum crucible at a temperature (793±25) K. the Melt is dissolved in 150 cmof a solution of monohydrate ammonium gidroksila when heated, the solution is transferred to a volumetric flask with a capacity of 250 cm, and topped to the mark with water. The solution to fit the application within two weeks.

1 cmof the solution contains 0.0005 g of tantalum.

Solution B: 2 cmof solution A is placed in a volumetric flask with a capacity of 250 cm, is poured a solution of monohydrate ammonium gidroksila to the mark and mix. Prepare before use.

1 cmof solution B contains 0,000004 g of tantalum.

5 procedures for measuring

5.1 the sample weighing 1.0 g was placed in a beaker with capacity of 500 cm, 100 cm pouredhydrochloric acid solution (1:1). Beaker cover watch glass or glass funnel and are dissolving at a moderate heat. The volume of the solution to maintain a constant, periodically adding a solution of hydrochloric acid (1:1). After complete dissolution of the sample in a solution poured about 1 cmof nitric acid to the bleaching solution and boil to remove oxides of nitrogen, then add 0.5 g of ascorbic acid and the solution diluted with water to about 200 cm. In a glass of solution is placed a paper weight, pour 100 cmof solution of tannin mass concentration of 30 g/DM, the beaker cover watch glass and boil the solution for 40−50 min, after which the solution was cooled and left for 7−8 h for the formation of a precipitate. Solution and the precipitate was filtered through ash-free filter medium density, «the white ribbon» and 3−4 times washed with hydrochloric acid solution (1:49). The filter with the precipitate is transferred into a platinum Cup, it is placed in a cold muffle furnace. During heating of the furnace sludge is dried, incinerated and then calcined at a temperature of (1303±25) K.

The residue carefully with disconnected ventilation is removed from the muffle furnace, add 5−6 drops of sulfuric acid, 5 cmhydrofluoric acid. Platinum content in the Cup is heated to release vapors of sulfuric acid and then evaporated to a state of wet sediment. To the residue poured in a Cup 5 cmof hydrochloric acid (1:1) and heated for several minutes to dissolve the precipitate. The solution was transferred to a beaker, which held the first deposition, rinse Cup with a little water, wipe it with a piece of filter paper, which is placed in the same Cup, and again rinse with a small amount of water. The washings are combined in a glass with a basic solution. The solution is poured 100−150 cmof a solution of tannin of the mass concentration of 10 g/DM, place filtrowanie mass, contribute 0.25 g of ascorbic acid, cover the beaker watch glass and boil the solution for about 1 h. Remove the beaker from the hotplate, poured to a hot solution of 50−70 cmof a hydrochloric acid solution (1:4), the solution was cooled and allowed to stand for 3−4 h.

Solution and the precipitate was filtered through a double filter of «white ribbon» and «red ribbon», washed it 3−4 times with hydrochloric acid (1:49), and then placed in a quartz crucible.

Quartz crucible with the precipitate is placed in a cold muffle furnace. During heating of the furnace sludge is dried, incinerated, and then calcined at a temperature of (1303±25) K.

The residue in the crucible is fused with potassium pyrosulphate a mass of 0.75 g at a temperature of (793±25) K for 3−5 min.

Crucible removed from the furnace, cool, add 10 cmof a solution of tartaric acid mass concentration of 40 g/DM, is heated to dissolve the melt. The solution was transferred to a volumetric flask with a capacity of 25 cm, top up to the mark with the same solution of tartaric acid and AC

eshivot.

5.2 For the determination of niobium aliquot part of the solution 10 cmis placed in a volumetric flask with a capacity of 50 cm, poured to a volume of 40 cm ina solution of hydrochloric acid (1:9), add 0.5 cmof the solution Trilon B, 2 cmof mortar linformazione-2 and heated to a temperature (343±10) K. After 15 min the solution was cooled to room temperature, made up to the mark with hydrochloric acid (1:9) and stirred.

Optical density of the solution measured on photocolorimeter or spectrophotometer at a wavelength of 670 nm (red filter for photocolorimetry) in a cuvette with a thickness of the absorbing layer is 50 mm. as a solution comparison solution is used in the reference experiment.

5.3 For determination of tantalum aliquot part of the solution is 5 cmis placed in a quartz test tube with a glass stopper with a capacity of 100 cm. Add with a pipette 2 cmof a solution of sodium fluoride, 1 cmof a solution of crystal violet, 10 cmof benzene (from burette) and extracted coloured complex within 1 min. After phase separation, the exact volume of a 5 cmlayer of benzene was placed in a dry test tube with a glass stopper, where pre-make 1 cmof acetone, and stirred. The optical density of the extract is measured on photocolorimeter or spectrophotometer at a wavelength of 590 nm (orange filter for photocolorimetry) in a cuvette with a thickness of the absorbing layer 10 mm. In a solution of comparison, using the extract solution of the reference experiment

.

5.4 Construction of calibration curve

5.4.1 To construct the calibration curve for the mass concentration of niobium from 0.002% to 0.01% in six of the seven volumetric flasks with a capacity of 50 cmplaced 0,8; 1,0; 2,0; 3,0; 4,0; 5,0 cmstandard solution B of niobium, which corresponds to 0,000008; 0,000010; 0,000020; 0,000030; 0,000040; 0,000050 g niobium. In all the seven vials poured a solution of hydrochloric acid (1:9) to a volume of about 40 cm, 0.5 cmof the solution Trilon B, add 2cmof a solution linformazione-2 and further receives, as specified in 5.2. As a solution comparison solution is used in the reference experiment.

5.4.2 For the construction of calibration curve for the mass concentration of the tantalum 0.001% to 0.005% in six of the seven quartz tubes for extraction with a capacity of 100 cmplaced 0,5; 1,0; 1,5; 2,0; 2,5; 3,0 cmstandard solution tantalum, which corresponds to 0,000002; 0,000004; 0,000006; 0,000008; 0,000010; 0,000012 g tantalum.

All seven test tubes pour 5 cmof the solution in the reference experiment, 2 cmof a solution of sodium fluoride and then do as specified in 5.3. A solution of comparison, using the extract obtained from the solution for the seventh test tube containing standard solution tantalum.

5.4.3 According to the obtained values of optical density and corresponding mass of niobium (tantalum) build the calibration graph.

6 Processing of measurement results

6.1 Mass fraction of niobium ,%, is calculated by the formula

, (1)

where is the mass of niobium 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.

6.2 the Mass percent of tantalum ,%, is calculated similarly.

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 specified in tables 1 and 2.


Table 1

Percentage

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 are standard solutions B.

8 qualifications

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