„Irgiredmet“ JSC (Irkutsk, Russia):

Bogorodskiy E. V., Leading Engineer, e-mail: e.bogor@mail.ru
Balikov S. V., Director of Business Center, Doctor of Engineering Sciences

Scientific-Research Institute „TOMS“ LLC (Irkutsk, Russia):

Rybkin S. G., Senior Researcher, Candidate of Engineering Sciences

There were carried out the researches on improvement of assay of sulphide ores and products of their processing, containing noble metals, for the purpose of decreasing of costs on their definition. Duration of instrumental analysis is decreased. Offered method of definition of noble metals includes mixing of test charge with fluxes, operation of thermal processing of charge with the temperature of 400–600 °С during 10–15 minutes and following smelting with the temperature of 1100–1200 °С with obtaining of slag and lead alloy. Lead bullion is cooled off and cupeled to silver or gold-silver regulus. Contents of noble metals in regulus are defined by chemical and physical-chemical methods. Tests of offered method of assay was carried out on standard samples of sulfide copper-nickel ores (content of sulfides, nickel and copper reached 40%, 10% and 7%, respectively). Together with comparison of results of definition of noble metals in standard samples with centrified contents, there was made a conclusion, that offered improved technology of assay makes it possible to obtain results of definition of noble metals, which are characterized by good convergence with certification values. This technology allows to exclude preliminary processing of samples (roasting and dissolution in acids) from the scheme of analysis, which makes analysis more economical and express. Aggressiveness of melted slag to crucibles is decreased, which increases the lifetime of crucible by 2-4 times. Melt viscosity is decreased, which corresponds to decreasing of mechanical losses of noble metals with slags. Such decreasing gives the possibility to exclude the secondary melting of slag from standard methods for the purpose of re-extraction of noble metals.

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