GOST 25278.8-82
GOST 25278.8−82 Alloys and alloys of rare metals. Method for the determination of samarium (Change No. 1)
GOST 25278.8−82
Group B59
STATE STANDARD OF THE USSR
ALLOYS AND ALLOYS OF RARE METALS
Method for the determination of samarium
Alloys and foundry alloys of rare metals. Method for determination of samarium
AXTU 1709
Valid from 01.07.83
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
Yu. A. Karpov, E. G. Nembrini, V. G., Miscreants, G. N. Andrianov, E. S. Danilin, M. A. Desyatkova L. I. Kirsanova, T. M. Malyutina, Y. F. Markov, V. M. Mikhailov, L. A. Nikitina, L. G. Obruchkova, N. Rasnitsyn, N. Suvorova, L. N. Filimonov
2. APPROVED AND put INTO EFFECT by Decision of the USSR State Committee for standards from
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 |
Section number, paragraph |
GOST 1381−73 |
Sec. 2 |
GOST 3118−77 |
Sec. 2 |
GOST 3760−79 |
Sec. 2 |
GOST 4461−77 |
Sec. 2 |
GOST 4463−76 |
Sec. 2 |
GOST 10398−76 |
Sec. 2 |
GOST 10652−73 |
Sec. 2 |
GOST 25278.5−82 |
Sec. 3 |
GOST 26473.0−85 |
1.1 |
6. Validity extended until
7. REPRINT (November 1988) with amendment No. 1, approved in October 1987 (ICS 1−88).
This standard specifies the method of chelatometric determination of samarium (35 to 40%) in binary alloys, samarium-cobalt.
The method is based on the formation complexonates samarium and cobalt, a subsequent destruction of complexonate samarium fluoride, and titrate the liberated Trilon B solution of zinc at a pH of 5.0−5.5 with indicator kylinalove orange.
1. GENERAL REQUIREMENTS
1.1. General requirements for methods of analysis and security requirements — according to GOST 26473.0−85.
(Changed edition, Rev. N 1).
2. APPARATUS, REAGENTS AND SOLUTIONS
Tile electric.
Analytical scale.
Libra technical.
Burette with a capacity of 50 and 10 cm.
Pipettes without dividing by 25 cm.
Conical flasks with a capacity of 250 cm.
Glasses glass with a capacity of 200 cm.
Measuring beakers with a capacity of 50 and 100 cm.
Volumetric flasks with a capacity of 100 and 1000 cm.
Nitric acid GOST 4461−77 diluted 1:1.
Hydrochloric acid by the GOST 3118−77, diluted 1:1.
Ammonia water according to GOST 3760−79 diluted 1:5.
Methenamine according to GOST 1381−73, a solution of 150 g/DM.
Sodium fluoride according to GOST 4463−76, a solution of 40 g/DM.
Indicator paper Congo.
Selenology orange, an aqueous solution of 1 mg/cm.
Salt is the disodium Ethylenediamine-N, N, N', N'-tetraoxane acid, 2-water (Trilon B) according to GOST 10652−73, solutions 70 g/land 0.025 mol/DM.
The Trilon B solution 0,025 mol/l; prepared as follows: 9.3 g Trilon B dissolved in water with heating (if the solution is turbid, it is filtered), transferred to a volumetric flask with a capacity of 1 DM, is cooled and adjusted to the mark with water. The ratio of the molarity of the solution Trilon B is determined by solution of salt of zinc (GOST 10398−76).
(Changed edition, Rev. N 1).
3. ANALYSIS
A portion of the sample weighing 0.5 g was placed in a conical flask with a capacity of 250 cm, 10−15 cm pouredhydrochloric acid and 10−15 cmof nitric acid, wash the walls of the bulb 10−15 cmof water and heated until complete dissolution of the sample. The solution was cooled, transferred to a volumetric flask with a capacity of 250 cm, was adjusted to the mark with water and mix (solution can be used for further determination according to GOST 25278.5−82).
In a conical flask with a capacity of 250 cmtaken 10 cmof the resulting solution, diluted to 100 cmwith water, neutralized paper Congo ammonia before the dyeing of paper of the Congo from blue to purple, add 10 cmof a solution of hexamine (pH 5,0−5,5 checked by universal indicator paper), add 3−5 drops of solution kylinalove orange and pour the solution Trilon B 70 g/DMto change the color of the solution from purple to pink. Excess Trilon B titrated with a solution of zinc to the transition of color from pink to purple. Add 30 cmof a solution of sodium fluoride, mix well, allow to stand for 40−50 min and titrated liberated Trilon B, the amount of which is equivalent to the number of samarium, a solution of the zinc until a steady crimson colors.
4. PROCESSING OF THE RESULTS
4.1. Mass fraction of Samaria () in percent is calculated by the formula
,
where is the volume of solution of zinc chloride, used for titration, cm;
0,003759 — the concentration of the solution Trilon B in Samaria, g/cm;
— the ratio of the molarity of the solution Trilon B;
— capacity volumetric flasks, cm;
— aliquotes volume of the solution taken for titration, cm;
— the weight of the portion of the sample, g
.
4.2. Discrepancies between the results of two parallel determinations and the results of the two tests should not exceed 0.5%.
Sec. 4. (Changed edition, Rev. N 1).