GOST 25278.16-87
GOST 25278.16−87 Alloys and alloys of rare metals. Methods of determination of rhenium (Change No. 1)
GOST 25278.16−87
Group B59
STATE STANDARD OF THE USSR
ALLOYS AND ALLOYS OF RARE METALS
Methods of determination of rhenium
Alloys and foundry alloys of rare metals. Methods for determination of rhenium
AXTU 1709
Valid from 01.07.88
to 01.07.93*
________________________________
* Expiration removed
according to the Protocol of the Intergovernmental Council
for standardization, Metrology and certification
(IUS N 2, 1993). — Note the manufacturer’s database.
INFORMATION DATA
1. DEVELOPED AND INTRODUCED by the Ministry of nonferrous metallurgy of the USSR
PERFORMERS
E. G. Nembrini, G. A. Andrianova, T. M. Malyutina, L. G. Obruchkova, E. I., Samsonova, Z. I. Shishkin, L. V. Ushakova
2. APPROVED AND promulgated by the Decree of the State Committee USSR on standards on 29 October 1987 N 4091
3. The period of examination — 1993
The frequency of inspection is 5 years.
4. INTRODUCED FOR THE FIRST TIME
5. REFERENCE NORMATIVE AND TECHNICAL DOCUMENTS
| The designation of the reference document referenced |
Item number |
| GOST 36−78* |
2.1, 3.1, 4.1 |
| ______________ * On the territory of the Russian Federation the document is not valid. Act THAT 6−09−5393−88** (IUS N 7, 1988); ** The document is the author’s development. For additional information, please refer to the link. — Note the manufacturer’s database. | |
| GOST 2603−79 |
2.1, 3.1 |
| GOST 3118−77 |
2.1, 3.1, 4.1 |
| GOST 3652−69 |
2.1 |
| GOST 3760−79 |
2.1, 4.1 |
| GOST 3769−78 |
2.1, 3.1 |
| GOST 5817−77 |
4.1 |
| GOST 4204−77 |
2.1, 3.1 |
| GOST 5828−77 |
2.1, 3.1 |
| GOST 6344−73 |
4.1 |
| GOST 10929−76 |
2.1, 3.1, 4.1 |
| GOST 18300−72* |
2.1 |
| GOST 26473.0−85 |
1.1 |
________________
* On the territory of the Russian Federation the document is not valid. Valid GOST 18300−87. — Note the manufacturer’s database.
The Change N 1, approved and introduced with effect from
Change No. 1 made by the manufacturer of the database in the text IUS N 6, 1998
This standard sets the photometric method for the determination of rhenium with dimethylglyoxime in binary alloys of hafnium (from 1 to 10%) in binary alloys of niobium (5 to 10%) in binary alloys based on tungsten (1 to 25%) and base alloys of tantalum containing hafnium and tungsten; differential photometric method for the determination of rhenium (from 25 to 50%) in binary alloys niobium-rhenium; photometric method for the determination of rhenium with thiourea in binary alloys based on molybdenum (20 to 50%) in binary alloys based on tungsten (from 0.5 to 30%); differential photometric method for the determination of rhenium (from 20 to 50%) in binary alloys, titanium-rhenium.
(Changed edition, Rev. N 1).
1. GENERAL REQUIREMENTS
1.1. General requirements for methods of analysis and security requirements — according to GOST 26473.0−85.
2. THE PHOTOMETRIC METHOD FOR THE DETERMINATION OF RHENIUM WITH DIMETHYLGLYOXIME
The method is based on formation of colored complex compounds of rhenium (IV) with dimethylglyoxime in sulfuric acid solution. As the reducing agent used tin dichloride. Hafnium, zirconium definition, do not interfere. Niobium mask with hydrogen peroxide, tantalum and tungsten — citric acid.
2.1. Apparatus, reagents and solutions
Photoelectrocolorimeter FEK-56 or similar device.
Analytical scale.
Libra technical.
Tile electric.
Volumetric flasks with a capacity of 50, 100, 250, 500 cmand 1 DM
.
Microburette with a capacity of 5 cm.
Pipette with divisions of 5 cm.
Pipettes without dividing by 5 and 10 cm.
Conical flasks with a capacity of 100 cm.
Watch-glasses with a diameter of 40 mm.
Nickel crucibles.
Sulfuric acid GOST 4204−77 and diluted 1:1.
Hydrochloric acid by the GOST 3118−77, diluted 1:1.
Ammonium sulfate according to GOST 3769−78.
Hydrogen peroxide according to GOST 10929−76.
Ammonia water according to GOST 3760−79.
Potassium hydroxide and a solution of 10 g/DM.
Citric acid according to GOST 3652−69, a solution of 100 g/DM.
The technical rectified ethyl alcohol GOST 18300−87.
Acetone according to GOST 2603−79.
Dimethylglyoxime according to GOST 5828−77, alcohol (acetone) a solution of 10 g/DM.
Tin dichloride, solution 100 g/l, prepared on the day of use: 10 g of tin dichloride was dissolved with heating in 15 cm
of hydrochloric acid diluted 1:1 and diluted with water to 100 cm
.
Rhenium metal containing at least 99.9% of rhenium.
A standard solution of rhenium (spare) containing 1 mg/cmof rhenium: 0.1 g of rhenium metal is dissolved by heating in 2−3 cm
of hydrogen peroxide. The resulting solution was cooled, transferred to a volumetric flask with a capacity of 100 cm
, adjusted to the mark with water.
A solution of rhenium (working) containing 100 µg/cmof rhenium is prepared by diluting the standard solution with water
10.
(Changed edition, Rev. N 1).
2.2. Analysis
2.2.1. For alloys based on niobium or hafnium
A portion of the sample mass of 0.2 g (with a mass fraction of rhenium from 1 to 4%) or 0.1 g (for the mass concentration of rhenium from 4 to 10%) is placed in a conical flask with a capacity of 100 cmand dissolved by heating on hot plates in 3 cm
of concentrated sulfuric acid in the presence of 3 g of ammonium sulfate, covering the flask with a watch glass (dissolution occurs within 10−15 min).
A transparent melt is cooled and dissolved by heating in 30 cmof water containing 2 cm
of hydrogen peroxide, transfer the solution into volumetric flask with a capacity of 100 cm
(with a mass fraction of rhenium from 1 to 4%) or 250 cm
(with a mass fraction of rhenium from 4 to 10%) is cooled and adjusted to the mark with water.
2.2.2. For alloys based on tantalum
A portion of the sample weighing 0.2 g was placed in a Nickel crucible, add 4 g of potassium hydroxide and fused in a muffle at a temperature of 600−700 °C to obtain a homogeneous melt. The smelt is leached with a hot solution of potassium hydroxide 10 g/DM; the solution and the precipitate was transferred to a volumetric flask with a capacity of 100 cm
and adjusted to the mark with a solution of potassium hydroxide.
2.2.3. For alloys based on tungsten
A portion of the sample weighing 0.1 g was placed in a conical flask with a capacity of 250 cm, flow 15 cm
of hydrogen peroxide, cover the flask with a watch glass and left at room temperature for 30−40 min. Then weakly heated until complete dissolution of the sample. To a cooled solution carefully, drop by drop, add 1 cm
of ammonia (appears yellow coloration) and again poorly heated until discoloration of the solution. The solution was cooled, transferred to a volumetric flask with a capacity of 100 cm
(with a mass fraction of rhenium from 1 to 5%) or 250 cm
(with a mass fraction of rhenium from 5 to 20%), cooled and adjusted to the mark with water.
2.2.4. For the determination of rhenium in a volumetric flask with a capacity of 50 cmis taken aliquot part of the solution (4.5 or 10 cm
) containing 100−500 µg of rhenium. In the analysis of the alloy based on tantalum, aliquot part taken from the alkaline solution, filtered through a dry filter medium density, or select aliquot part of the transparent part of the solution after settling of the precipitate until the next day.
Add 2cmof a solution of citric acid (for alloys based on tantalum, tungsten), 4.5 cm poured
sulphuric acid, diluted 1:1, up to 15 cm
of water 5 cm
of the solution dimethylglyoxime, 3 cm
of a solution of tin dichloride while stirring the solutions after each addition of reagent, adjusted to the mark with water, mix.
After 1 hour measure optical density of solution on a photoelectrocolorimeter at 
Mass of rhenium found by calibration curve
.
2.2.5. Construction of calibration curve
In a volumetric flask with a capacity of 50 cmis injected from microburette 1,0; 2,0; 3,0; 4,0 and 5,0 cm
working solution of rhenium, which corresponds to 100, 200, 300, 400 and 500 micrograms of rhenium. Pour 2 cm
of a solution of citric acid (for alloys based on tantalum or tungsten), 4.5 cm
of sulphuric acid diluted 1:1, up to 15 cm
of water 5 cm
of the solution dimethylglyoxime, 3 cm
of a solution of tin dichloride while stirring the solutions after each addition of reagent, adjusted to the mark with water and mix again. After 1 hour measure optical density of solutions on the photoelectrocolorimeter at
According to the obtained results build a calibration curve in the coordinates of the optical density — the mass of rhenium. Separate test points of the graph along with the analysis of Pro
b.
2.3. Processing of the results
2.3.1. Mass fraction of rhenium () in percent is calculated by the formula
where is the mass of the rhenium was found in the calibration graphics mg;
— capacity volumetric flasks, cm
;
— aliquotes volume of the solution taken for the determining, cm
;
— the weight of the portion of the sample,
2.3.2. Discrepancies between the results of two parallel determinations and the results of the two tests should not exceed the values of permissible differences given in table.1.
Table 1
| Mass fraction of rhenium, % |
The allowable divergence, % |
| 1,0 | 0,1 |
| 5,0 |
0,2 |
| 10,0 | 0,4 |
| 20,0 | 0,8 |
| 25,0 |
1,2 |
3. DIFFERENTIAL PHOTOMETRIC METHOD FOR THE DETERMINATION OF RHENIUM
The method is based on formation of colored complex compounds of rhenium (IV) with dimethylglyoxime in the sulfate medium. The optical density of the solutions is measured relative to the comparison solution containing 1.0 mg of rhenium. Niobium mask with hydrogen peroxide.
3.1. Apparatus, reagents and solutions
Brand spectrophotometer SF-26 or similar device.
Analytical scale.
Libra technical.
Tile electric.
Volumetric flasks with a capacity of 50, 100, 200 and 250 cm.
Microburette with a capacity of 5 cm.
Pipettes with graduation marks at 5 and 10 cm.
Conical flasks with a capacity of 50 cm.
Watch-glasses with a diameter of 40 mm.
Sulfuric acid GOST 4204−77, diluted 1:1, and a solution of 2 mol/DM.
Hydrochloric acid by the GOST 3118−77, diluted 1:1.
Ammonium sulfate according to GOST 3769−78.
Hydrogen peroxide according to GOST 10929−76.
The technical rectified ethyl alcohol GOST 18300−87.
Dimethylglyoxime according to GOST 5828−77, alcoholic solution of 10 g/DM.
Tin dichloride, solution 100 g/l, prepared on the day of use: 10 g of tin dichloride was dissolved with heating in 15 cm
of hydrochloric acid diluted 1:1 and diluted with water to 100 cm
.
Solution reagent: to 100 cmof sulphuric acid 2 mol/DM
add 2 cm
of hydrogen peroxide and dilute with water to 250 cm
.
Potassium renewably.
A standard solution of rhenium (spare) containing 1 mg/cmof rhenium: 0,1550 g of potassium perrhenate dissolved by heating in water, transferred to a volumetric flask with a capacity of 100 cm
, cooled and adjusted to the mark with water.
A solution of rhenium (working) containing 100 µg/cmof rhenium is prepared by diluting the standard solution with water
10.
(Changed edition, Rev. N 1).
3.2. Analysis
3.2.1. A portion of the sample mass of 0.2 g (with a mass fraction of rhenium from 25 to 30%) or 0.15 g (at a mass fraction of rhenium 40%) or 0.1 g (for the mass concentration of rhenium 50%) was placed in a conical flask with a capacity of 50 cmand dissolved by heating on hot plates in 3 cm
of concentrated sulfuric acid in the presence of 0.3 g of ammonium sulfate, covering the flask with a watch glass (dissolution occurs within 10−15 min).
The clear solution is cooled, add 30−40 cmof water containing 2 cm
of hydrogen peroxide, heated to boiling, cool and transfer the solution into volumetric flask with a capacity of 200 cm
(with a mass fraction of rhenium from 30 to 40%) or 250 cm
(with a mass fraction of rhenium from 40 to 50%), adjusted to the mark with water.
3.2.2. For the determination of rhenium in a volumetric flask with a capacity of 50 cmis taken aliquot part of the solution (5 cm.
) containing 1.1−1.3 mg of rhenium (and not more than 3 mg of niobium), add 3 cm
of sulphuric acid diluted 1:1, 15 cm
of water 5 cm
of the solution dimethylglyoxime, 4 cm
of a solution of tin dichloride, stirring after each addition of reagent (addition of reagents must be done quickly), adjusted to the mark with water.
After 2 h (colored solutions are stable for 6 h), measure the optical density of the solution on the spectrophotometer at 440 nm in a cuvette with the thickness of the light absorbing layer 10 mm relative to the comparison solution containing 1.0 mg of rhenium: in a volumetric flask with a capacity of 50 cm
is taken 10 cm
working solution of rhenium, 5 cm
of a solution of reagents, add 3 cm
of sulphuric acid diluted 1:1, 15 cm
of water 5 cm
of the solution dimethylglyoxime, 4 cm
of a solution of tin dichloride, stirring after each addition of reagent, bring to mark with water. After 3 h the solution is used as solution CP
annenia.
3.2.3. Construction of calibration curve
In a volumetric flask with a capacity of 50 cmimpose 10,0; 11,0; 12,0 and 13.0 cm
working solution of rhenium, which corresponds to 1,0; 1,1; 1,2 and 1,3 mg of rhenium. Pour 5 cm
of a solution of reagents, add 3 cm
of sulphuric acid diluted 1:1, 15 cm
of water 5 cm
of the solution dimethylglyoxime, 4 cm
of a solution of tin dichloride while stirring after adding each reagent, adjusted to the mark with water.
After 2 h, measure the optical density of solutions containing 1.1 to 1.3 mg of rhenium, relative to a solution containing 1.0 mg of rhenium on the spectrophotometer at 440 nm in a cuvette with the thickness of the light absorbing layer 10 mm.
According to the obtained results build a calibration curve in the coordinates of the optical density — the mass of rhenium. Separate test points of the graph along with the analysis of Pro
b.
3.3. Processing of the results
3.3.1. Mass fraction of rhenium () in percent is calculated by the formula
where is the mass of the rhenium was found in the calibration graphics mg;
— capacity volumetric flasks, cm
;
— aliquotes volume of the solution taken for the determining, cm
;
— the weight of the portion of the sample,
3.3.2. Discrepancies between the results of two parallel determinations and the results of the two tests should not exceed the values of permissible differences given in table.2.
Table 2
| Mass fraction of rhenium, % |
The allowable divergence, % |
| 25,0 | 0,7 |
| 30,0 |
0,8 |
| 40,0 |
1,1 |
| 50,0 |
1,4 |
4. THE PHOTOMETRIC METHOD FOR THE DETERMINATION OF RHENIUM WITH THIOUREA
The method is based on formation of colored complex compounds of rhenium (IV) with thiourea in hydrochloric acid medium. As the reducing agent used tin dichloride. Tungsten and molybdenum mask tartaric acid.
4.1. Apparatus, reagents and solutions
Photoelectrocolorimeter FEK-56 or similar device.
Analytical scale.
Libra technical.
Tile electric.
Volumetric flasks with a capacity of 25, 100 and 1000 cm.
Microburette with a capacity of 5 cm.
Pipette with divisions of 5 cm.
Pipettes without dividing by 5 and 10 cm.
Conical flasks with a capacity of 250 cm.
Watch-glasses with a diameter of 40 mm.
Bath water.
Hydrogen peroxide according to GOST 10929−76.
Tartaric acid according to GOST 5817−77, the solutions are 30 and 150 g/DM.
Hydrochloric acid by the GOST 3118−77.
Ammonia water according to GOST 3760−79.
Thiourea according to GOST 6344−73, a solution of 100 g/DM.
Tin dichloride, a solution of 200 g/DM, prepared on the day of use: 20 g of tin dichloride was dissolved with heating in 50 cm
of hydrochloric acid, cool, transfer the solution into a volumetric flask with a capacity of 100 cm
, adjusted to the mark with water.
Ammonium renewably.
A standard solution of rhenium (spare) containing 0.2 mg/cm, is prepared in one of two ways:
Method 1: 0,2882 g of ammonium perrhenate dissolved in water, transferred to a volumetric flask with a capacity of 1 DM, adjusted to the mark with water.
Method 2: 0,3100 g of potassium perrhenate dissolved by heating in water, transferred to a volumetric flask with a capacity of 1 DM, cooled, adjusted to the mark with water.
A solution of rhenium (working) containing 50 µg/cmof rhenium is prepared by diluting a standard solution with water
4 times.
(Changed edition, Rev. N 1).
4.2. Analysis
4.2.1. A portion of the sample weighing 0.1 g was placed in a conical flask with a capacity of 250 cmand dissolved by heating in a water bath 10 cm
of hydrogen peroxide, cover the flask with a watch glass and adding additional as necessary hydrogen peroxide until complete dissolution of the alloy. Upon dissolution of the hanging wall of the flask and the watch glass washed with 5−10 cm
of water, the solution was cooled. Add carefully, drop by drop ammonia (3−4 cm
) to the bleaching solution and the end of bubbles. The solution was boiled for few minutes for complete destruction of hydrogen peroxide, transferred to a volumetric flask with a capacity of 100 cm
, add 20 cm
of a solution of tartaric acid is 150 g/DM
, cooled, adjusted to the mark with water. The solution was diluted again (at the expected mass fraction of rhenium more than 5%): in a volumetric flask with a capacity of 100 cm
pipetted 10 cm
of the solution and bring to mark with a solution of tartaric acid 30 g/
DM.
4.2.2. For the determination of rhenium in a volumetric flask with a capacity of 25 cmis taken aliquot part of the solution (5 or 10 cm
) containing 50 to 250 micrograms of rhenium, diluted (if necessary) up to 10 cm
with a solution of tartaric acid 30 g/DM
, poured 5cm
of hydrochloric acid and dilute with water to 20 cm
. Then add 2.5 cm
of a solution of thiourea and 1 cm
of a solution of tin dichloride while stirring after adding each reagent, adjusted to the mark with water.
After 40 min, measure the optical density of the solution on photoelectrocolorimeter at 
Mass of rhenium find for the calibration.
ku.
4.2.3. Construction of calibration curve
In a volumetric flask with a capacity of 25 cmis introduced from microburette 1,0; 2,0; 3,0; 4,0 and 5,0 cm
working solution of rhenium, which corresponds to 50, 100, 150, 200 and 250 micrograms of rhenium, is added to 10 cm
of a solution of tartaric acid 30 g/DM
, poured 5cm
of hydrochloric acid, dilute with water to 20 cm
. Then add 2.5 cm
of a solution of tin dichloride while stirring after adding each reagent, adjusted to the mark with water. In one of the flasks poured all the reagents, except for the rhenium (zero solution). After 40 min, measure the optical density of solutions on the photoelectrocolorimeter at
According to the obtained results build a calibration curve in the coordinates of the optical density — the mass of rhenium. Separate test points of the graph along with the analysis of Pro
b.
4.3. Processing of the results
4.3.1. Mass fraction of rhenium () in percent (mass fraction of rhenium in the 0.5−5%) is calculated according to the formula
where is the mass of the rhenium was found in the calibration schedule, mcg;
— capacity volumetric flasks, cm
;
— aliquotes volume of the solution taken for the determining, cm
;
— the weight of the portion of the sample,
4.3.2. Mass fraction of rhenium () in percent (mass fraction of rhenium more than 5%) is calculated according to the formula
where is the mass of the rhenium was found in the calibration graphics mg;
the capacity of volumetric flasks at the first dilution, cm
;
the capacity of the volumetric flask for the second dilution solution, cm
;
— aliquotes volume of the solution taken for dilution, cm
;
— aliquotes volume of the solution taken for the determining, cm
;
— the weight of the portion of the sample,
G.
4.3.3. Discrepancies between the results of two parallel determinations and the results of the two tests should not exceed the values of permissible differences given in table.3.
Table 3
| Mass fraction of rhenium, % |
The allowable divergence, % |
| 0,5 | 0,04 |
| 1,0 |
0,08 |
| 5,0 |
0,3 |
| 10,0 |
0,6 |
| 15,0 |
0,8 |
| 20,0 |
1,1 |
| 25,0 |
1,4 |
| 30,0 |
1,7 |
| 40,0 |
1,9 |
| 50,0 |
2,2 |
5. Differential photometric method for the determination of rhenium with thiourea
The method is based on formation of colored complex compounds of rhenium (IV) with thiourea in hydrochloric acid medium in the presence of tin dichloride (reducing agent). The optical density of the solutions is measured relative to the comparison solution containing 2.0 mg of rhenium. Titan definition does not interfere.
5.1. Apparatus, reagents and solutions
The spectrophotometer SF-26 or similar device.
Analytical scale.
Libra technical.
Tile electric.
Muffle furnace with thermostat, providing a temperature of 500−600 °C.
Volumetric flasks with a capacity of 50, 100 cm.
Pipettes with graduations at 2, 5 and 10 cm.
Glasses chemical glass with a capacity of 100−150 cm.
The Nickel crucible with a capacity of 30 cm.
Sodium hydroxide according to GOST 4328−77.
Sodium nitrate according to GOST 4168−79.
Hydrochloric acid by the GOST 3118−77.
Thiourea according to GOST 6344−73, a solution of 100 g/DM.
Tin dichloride, a solution of 200 g/DM, prepared on the day of use: 2.0 g of tin dichloride was dissolved with heating in 50 cm
of hydrochloric acid, cooled, transferred to a volumetric flask with a capacity of 100 cm
, adjusted to the mark with water and mix.
Potassium renewably (perrenate potassium).
A standard solution of rhenium (spare) containing 1 mg/cmof rhenium: 0,1550 g of potassium perrhenate dissolved by heating in water. Cooled, transferred to a volumetric flask with a capacity of 100 cm
and adjusted to the mark with water.
A solution of rhenium (working) containing 100 µg/cm, is prepared by dilution of a standard solution with water in 10 times.
5.2. Analysisof hot water in a glass with a capacity of 150 cm
when heated, add 20−30 cm
of hydrochloric acid to obtain a clear solution. The solution was cooled, transferred to a volumetric flask with a capacity of 100 cm
, adjusted to the mark with water.
For the determination of rhenium in a volumetric flask with a capacity of 50 cmis taken aliquot part of the solution (5−10 cm
) containing 2.1 and 2.7 mg of rhenium, poured 10 cm
of hydrochloric acid of 5 cm
of a solution of tin dichloride while stirring after adding each reagent, and adjusted to the mark with water.
After 40 min, measure the optical density of the solution in the spectrophotometer SF-26 at 390 nm in a cuvette with the thickness of the light absorbing layer 10 mm relative to the comparison solution containing 2.0 mg of rhenium.
Mass of rhenium find the schedule for the calibration or using a calibration factor.
Eight volumetric flasks with a capacity of 50 cmeach injected with 2 cm
of a standard solution of rhenium, and then sequentially, starting from the second flask, add 1, 2, 3, 4, 5, 6 and 7 cm
of the working solution of rhenium, which corresponds to 2,0; 2,1; 2,2; 2,3; 2,4; 2,5; 2,6 and 2.7 mg of rhenium. Pour 10 cm
of hydrochloric acid and then act as described in paragraph
According to the obtained values of optical density and corresponding mass of rhenium build a calibration curve or calculate the calibration factor according to GOST 26473.0−85, p. 16.
5.3. Processing of the results) in percent is calculated by the formula
where is the mass of titanium in solution comparisons, mg;
— the optical density of the analyzed solution in relation to solution comparison;
— calibration factor;
— capacity volumetric flasks, cm
;
— the weight of the portion of the sample, g;
— volume aliquote part of the solution, cm
.
Table 4
| Mass fraction of rhenium, % | The allowable divergence, % |
| 20,0 | 0,5 |
| 30,0 | 0,7 |
| 40,0 | 0,9 |
| 50,0 | 1,1 |
Section 5. (Added, Rev. N 1).
