GOST 12564.1-83
GOST 12564.1−83 Alloys gold-palladium-platinum. Method for the determination of gold, palladium (with Change No. 1)
GOST 12564.1−83
Group B59
STATE STANDARD OF THE USSR
ALLOYS GOLD-PALLADIUM-PLATINUM
Method for the determination of gold, palladium*
Aurrum-palladium-platinum alloys.
Methods for the determination of aurrum, palladium, platinum
AXTU 1709**
______________
* The name of the standard. Changed the wording, Rev. N 1.
** Changed revision, Rev. 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. Belyaev, E. E. Safonova
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 1374
REPLACE GOST 12564−67 in part of sec. 2, 3, 4
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 1, 1989
This standard specifies a gravimetric method for the determination of gold, palladium, gold-palladium-platinum alloys (in mass fraction of gold from of 59.0 to 61.0%, palladium from up to 31,0 29,0%).
The method is based on the recovery of gold in the presence of palladium and platinum by sodium nitrite, the precipitation of palladium in the form of dimethylglyoximate from a solution of sodium nitropyridine.
(Changed edition, Rev. N 1).
1. GENERAL REQUIREMENTS
1.1. General requirements for method of analysis according to GOST 22864−83.
(Changed edition, Rev. N 1).
1.2. The result of the analysis should end with the figure of the same category, and permissible differences.
(Added, Rev. N 1).
2. APPARATUS, REAGENTS AND 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 according to GOST 13474−79.
From Kipp apparatus for generating hydrogen.
Crucibles porcelain No. 4, 5 according to GOST 9147−80.
Flasks laboratory glass according to GOST 25336−82, with a capacity of 500, 1000 cm.
Volumetric flasks glass according to GOST 1770−74, with a capacity of 500 cm.
Beakers, glass, laboratory for GOST 25336−82, with a capacity of 150 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, 6 M and diluted 1:99.
Nitric acid GOST 4461−77.
Sulfuric acid GOST 4204−77 and diluted 1:5.
The mixture of acids to dissolve consisting of three volumes of hydrochloric acid and one volume of nitric acid.
Sodium atomistically according to GOST 4197−74, 7 M solution.
Dimethylglyoxime according to GOST 5828−77, saturated solution.
(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 50 cm
of mixture of acids. The solution was evaporated to approximately 3 cm
. Upon evaporation of the solution may a partial restoration of the gold to the metal and loss it in the form of fine sediment on the bottom of the flask. Not filtering out the precipitate, the solution is diluted with hot water up to 300 cm
with the addition of 1−2 cm
of hydrochloric acid for complete dissolution of palladium salt.
In parallel with the analysis of alloy spend control experience. This 50 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 analysis (PP.4.1; 4.2; 4.3).
4. ANALYSIS
4.1. Gravimetric method for determination of gold
To a hot solution of the alloy is carefully poured 100 cm7 M solution of sodium attestatio.
The solution, while 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).
The residue in the crucible is cooled, pour water with a few drops of nitric acid (to dissolve sodium salts), heat for 20−30 min, transferred to a filter, washed with hot water, dried, calcined and weighed. Calcination is repeated until obtaining constant weight.
(Changed edition, Rev. N 1).
4.2. Gravimetric method for determination of content of palladium
The filtrate after separation of the gold is transferred in a volumetric flask with a capacity of 500 cm, adjusted to the mark with distilled water and mix. For the determination of palladium aliquot part of the solution is 250 cm
(which corresponds to a weight of 0.5 g of alloy) is transferred to a conical flask with a capacity of 1000 cm
, add 100 cm
of water a saturated solution of dimethylglyoxime, 200 cm
hot distilled water, incubated at room temperature for 1 hour for complete coagulation of the precipitate and filtered through the filter «red ribbon».
Glyoxylate palladium precipitate is filtered off, washed with 100 cmof hydrochloric acid (1:99), then with hot water until neutral (water temperature should not be above 85 °C). The filter with precipitate was placed in a tared porcelain crucible, dried at room temperature and calcined in a muffle furnace with a gradual temperature increase to 400 °C.
Restore the calcined precipitate for 5−10 min at 900−1000 °C in a current of hydrogen, cooled and weighed.
4.3. (Deleted, Rev. N 1).
5. PROCESSING OF THE RESULTS
5.1. Mass fraction of gold (palladium) () percentage calculated by the formula
where is the mass of the precipitate of gold (palladium), g;
— the mass of sediment in the reference experiment, g;
— the weight of the portion of alloy,
5.2. The difference between the largest and smallest results of parallel measurements at a confidence probability of 0.95 does not exceed the allowable absolute differences of 0.25% in the determination of gold and 0.30 percent in the determination of palladium.
The difference between the results of two analyses of the same sample obtained in different laboratories, should not exceed the allowable absolute differences of 0.40% in the determination of gold and 0.45% in the determination of palladium.
5.1, 5.2. (Changed edition, Rev. N 1).
5.3. The accuracy of the results of determination of mass fractions of gold and palladium control the reproduction of their 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 absolute difference between the highest and lowest value must not exceed for gold to 0.20% of palladium and 0.25%.
(Added, Rev. N 1).
