GOST 12552.1-77
GOST 12552.1−77 Alloys, platinum-Nickel. Method for the determination of Nickel (with Change No. 1)
GOST 12552.1−77
Group B59
STATE STANDARD OF THE USSR
ALLOYS, PLATINUM-NICKEL
Method for the determination of Nickel
Platinum-nickel alloys. Method for the determination of nickel
AXTU 1709*
______________
* Code standard. Introduced later, Rev. N 1.
Valid from 01.01.1979
to 01.01.1984*
_______________________________
* Expiration removed
Protocol N 3−93 Interstate Council
for standardization, Metrology and certification
(IUS No. 5/6, 1993). — Note the manufacturer’s database.
DEVELOPED by Sverdlovsk factory on processing of nonferrous metals
Director S. G. Gushchin
Heads: V. G. Levin, V. D. Ponomareva
Performers: M. P. Yufa, N. With. Stepanova, N. And. Chentsova, R. M. Bogdanova
INTRODUCED by the Ministry of nonferrous metallurgy of the USSR
Zam. Minister V. S. Ustinov
The draft all-Union scientific research Institute of standardization (VNIIS)
Director A. V. Gichev
APPROVED AND promulgated by the Decree of the State Committee of standards of Ministerial Council of the USSR of 27 December 1977 N 3069
REPLACE GOST 12552−67 in part of sec. 2
The Change N 1, approved and put into effect by the Decree of the USSR State Committee for standards from
Change No. 1 made by the manufacturer of the database in the text IUS N 9, 1988
This standard specifies the titrimetric method for the determination of Nickel (at a mass fraction of Nickel from 4.0 to 30%).
The method is based on binding of Nickel to the compound dwuzameshchenny the sodium salt of ethylenediaminetetraacetic acid (Trilon B) at pH 5 and titrate the excess Trilon B with a solution of acetate of zinc with indicator kylinalove orange.
1. GENERAL REQUIREMENTS
1.1. General requirements for method of analysis according to GOST 22864−83.
(Changed edition, Rev. N 1).
1.2. The numerical value of the result of the analysis must end with a digit of the same rank as that of the normalized indicator grade composition.
(Added, Rev. N 1).
2. APPARATUS, REAGENTS AND SOLUTIONS
Laboratory scales lever according to GOST 24104−80*.
_______________
* On the territory of the Russian Federation GOST 24104−2001. — Note the manufacturer’s database.
Conical flasks with a capacity of 250 cmaccording to GOST 25336−82.
Volumetric flasks with a capacity of 250 cmaccording to GOST 1770−74.
Burette with automatic zero setting capacity of 50 cm.
Pipettes with a capacity of 10, 20, 25 and 50 cmaccording to GOST 20292−74*.
________________
* On the territory of the Russian Federation there are 29169−91 GOST, GOST 29227−91−29229−91 GOST, GOST 29251−91-GOST 29253−91. — Note the manufacturer’s database.
Hydrochloric acid by the GOST 3118−77.
Nitric acid GOST 4461−77.
A mixture of acids, consisting of one volume of nitric acid and three volumes of hydrochloric acid.
Salt is the disodium Ethylenediamine-N, N, N', N'-tetraoxane acid, 2-water (Trilon B) according to GOST 10652−73, of 0.075 M solution; prepared as follows: 27,9 g of salt is dissolved by heating in 500 cmof water and bring the volume to 1000 cm
water.
Zinc acetate according to GOST 5823−78, 0.1 M solution is prepared as follows: to 9.15 g of salt dissolved in 500 cmof water and bring the volume to 1000 cm
water.
Sodium acetate according to GOST 199−78, a solution with a mass fraction of 50%.
Selenology orange indicator solution with a mass fraction of 0.20.
Nickel GOST 849−70*.
________________
* On the territory of the Russian Federation GOST 849−97**;
**
A standard solution of Nickel; prepared as follows: 0,5000 g of Nickel was dissolved with heating in 30 cmdiluted 1:1 nitric acid, evaporated to a volume of 5−10 cm
and twice by evaporation with 10 cm
of hydrochloric acid diluted 1:1, transferred into hydrochloric acid, the volume was adjusted in a volumetric flask with a capacity of 500 cm
to the mark with water and mix.
1 cmof the solution contains 0.001 g of Nickel.
(Changed edition, Rev. N 1).
3. PREPARATION FOR ASSAY
Two sample alloy (in the form of strips or chips) weighing 2.5 g placed in a conical flask with a capacity of 250 cmand dissolved by heating at 40 cm
of a mixture of acids. The solution was evaporated to a syrupy condition, transferred into hydrochloric acid by two-fold evaporation with 10 cm
diluted 1:1 hydrochloric acid and poured 25 cm
of water.
(Changed edition, Rev. N 1).
4. ANALYSIS
4.1. Setting the ratio of Trilon B with acetic acid zinc
Pipette or burette take 10 cmof the solution Trilon B, is placed in a conical flask with a capacity of 250 cm
, flow 20 cm
water, 5 cm
of a solution of sodium acetate, 10 drops of the indicator solution kylinalove orange and titrated with a solution of zinc acetate until the color of solution from yellow to crimson.
At the same time three definitions.
Ratio () is calculated by the formula
where — volume of solution Trilon B, cm
;
— the volume of solution of acetate of zinc, cm
.
4.2. Determination of the titer of the solution Trilon B Nickel
20 cmstandard solution of Nickel was placed in a conical flask with a capacity of 250 cm
, poured with a pipette or a burette 20 cm
of the solution Trilon B, 10 cm
of a solution of sodium acetate, six drops of kylinalove orange indicator and titrated with a solution of zinc acetate until the color changes from dirty-green to crimson.
Caption (), expressed in g/l of Nickel, calculated as follows:
where is the mass of Nickel contained in 20 cm
standard solution, g;
— the number of solution Trilon B, cm
;
— number of solution of acetate of zinc, consumed in the titration, cm
;
the ratio of Trilon B with acetic acid zinc
.
4.3. The determination of Nickel
Prepared for analysis hydrochloric acid solution of the analyzed alloy was transferred into a measuring flask with a capacity of 250 cm, was adjusted to the mark with water and mix thoroughly.
Of take volumetric flasks pipette two aliquots of 50 cm, which is placed in a conical flask with a capacity of 250 cm
. Then the solution is poured with a pipette or burette 25 cm
of the solution Trilon B, 20 cm
of water and 20 cm
of a solution of sodium acetate to create a pH of 5.
Excess Trilon B octarepeat solution of acetate of zinc in the presence of an indicator kylinalove orange (5−6 drops) until the color of solution from dirty-green to crimson.
4.1−4.3. (Changed edition, Rev. N 1).
5. PROCESSING OF THE RESULTS
5.1. Mass fraction of Nickel () in percent is calculated by the formula
where — volume of solution Trilon B added for the formation of a complex of Nickel, cm
;
— the volume of solution of acetate of zinc, consumed in the titration of excess Trilon B, cm
;
the ratio of Trilon B with acetic acid and zinc;
the titer of the solution Trilon B Nickel, g/cm
;
— weight of alloy, suitable aliquote part of the solution, g;
— mass fraction of palladium in the alloy is determined by the spectral method,
%.
5.2. Allowable absolute differences between the results of parallel measurements (the rate of convergence) at a confidence probability
of 0.95, should not exceed 0.20%.
Allowable absolute differences of average results of determinations obtained in two different laboratories (a measure of reproducibility) shall not exceed 0.30 percent.
5.1, 5.2. (Changed edition, Rev. N 1).
5.3. The control of correctness of analysis results
Control of the correctness of the results of determining the mass fraction of Nickel is playing its mass fraction in the artificial mixtures the chemical composition close to the composition of the analyzed alloy, drawn through the entire course of the analysis.
The sample analysis results are considered correct if the absolute difference between the maximum and minimum values of the mass fraction of Nickel in synthetic mixture does not exceed about 0.06% when the mass fraction of Nickel from 4.0 to 5.0% and 0.17% when the mass fraction of Nickel from 20 to 30%.
(Added, Rev. N 1).
