GOST 12563.1-83
GOST 12563.1−83 Alloys gold-palladium. Method for the determination of gold (Change No. 1)
GOST 12563.1−83
Group B59
STATE STANDARD OF THE USSR
ALLOYS OF GOLD-PALLADIUM
Method for the determination of gold
Gold-palladium alloys.
Method for the determination of gold
GST 17 5350
AXTU 1709*
______________
* Introduced later. Izm. N 1.
Valid from 01.07.84
to 01.07.89*
_________________________________
* Expiration removed by Protocol No. 3−93
The interstate Council for standardization,
Metrology and certification (ICS No. 5/6, 1993). -
Note the manufacturer’s database.
DEVELOPED by the Ministry of nonferrous metallurgy of the USSR
PERFORMERS
A. A. Kuranov, G. S. HAK, N. With. Stepanova, N. D. Sergienko, T. I. Belyaeva
INTRODUCED by the Ministry of nonferrous metallurgy of the USSR
Member Of The Board Of A. P. Snurnikov
APPROVED AND promulgated by the Decree of the State Committee USSR on standards on March 25, 1983 N 1373
REPLACE GOST 12563−67 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 2, 1989
This standard specifies a gravimetric method for the determination of gold in gold-palladium alloys (with a mass fraction of gold from to 50,0 90,0%).
The method is based on the recovery of gold by sodium nitrite in the presence of palladium; however, palladium remains in solution in the form of micropellet sodium.
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 the digit the same category, and permissible differences.
(Added, Rev. N 1).
2. EQUIPMENT, REAGENTS, SOLUTIONS
Laboratory scales General purpose and model according to GOST 24104−80*.
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* On the territory of the Russian Federation GOST 24104−2001. — Note the manufacturer’s database.
Electric resistance furnace laboratory.
Crucibles porcelain No. 4 according to GOST 9147−80.
Flasks laboratory glass according to GOST 25336−82, with a capacity of 500 cm.
Funnel glass according to GOST 25336−82, type B.
Laboratory filter paper according to GOST 12026−76.
Hydrochloric acid by the GOST 3118−77.
Nitric acid GOST 4461−77.
The mixture of acids to dissolve consisting of three volumes of concentrated hydrochloric acid and one volume of concentrated nitric acid.
Sulfuric acid GOST 4204−77, diluted 1:5.
Sodium atomistically according to GOST 4197−74, the solution concentration of 7 mol/DM.
(Changed edition, Rev. N 1).
3. PREPARATION FOR ASSAY
A sample of alloy weighing 1.0 g was placed in a conical flask with a capacity of 500 cmand dissolved by heating in 30 cm
of a mixture of acids. The solution was evaporated to approximately 3 cm
and dilute with hot water, adding 1−2 cm
of hydrochloric acid until complete dissolution of palladium salt.
4. ANALYSIS
Upon evaporation of the solution may a partial restoration of the gold and its deposition in the form of fine sludge at the bottom of the flask. Not filtering out the precipitate, the solution is diluted with hot water up to 300 cmand gently poured 100 cm
of solution concentration of 7 mol/DM
sodium attestatio.
The solution, maintaining the original volume, boiled for 1.5−2 h prior to the removal of nitrogen oxides and total coagulation of the precipitate. The palladium remains in solution in the form of complex compounds of gold and ferric hydroxide are transferred into the sediment.
After cooling the solution the precipitate was filtered off through the filter of «white ribbon» filled with one-fourth of the paper pulp, and washed with hot water until neutral. Funnel and the precipitate was transferred to another flask and pour hot sulfuric acid (1:5) for dissolution of iron hydroxide. Remaining on the filter, the precipitate of gold is washed with hot water until neutral, dried, put into a tared porcelain crucible and calcined in a muffle furnace for 1 h until complete ashing of the filter (temperature not over 800 °C). After cooling, the precipitate in the crucible is filled with water with a few drops of nitric acid to dissolve the sodium salts, warm up 20−30 min, filtered off, washed with hot water, dried, calcined and weighed. Calcination is repeated until obtaining constant weight.
In parallel with the sample hold control experience. This 30 cmof the mixture of acids is placed in a conical flask with a capacity of 500 cm
and is carried out through all stages of the analysis.
(Changed edition, Rev. N 1).
5. PROCESSING OF THE RESULTS
5.1. Mass fraction (gold) in percent is calculated by the formula
where is the mass of the precipitate of gold, g;
— the mass of sediment in the reference experiment, g;
— the weight of the portion of alloy,
5.2. The difference between the highest and lowest results of parallel measurements at a confidence probability of 0.95 does not exceed the absolute value of the admitted differences
of 0.20%.
The difference between two results of analysis of the same sample obtained in different laboratories, should not exceed the absolute value of the admitted differences of 0.35%.
(Changed edition, Rev. N 1).
5.3. Accuracy control in the determination of the mass fraction of gold 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 accurate if the absolute difference between the largest and smallest values of the mass fraction of gold in an artificial mixture does not exceed 0,17%.
(Added, Rev. N 1).
