PYRITE CINDER PROCESSING METHOD Russian patent published in 2020 - IPC C22B3/10 C22B7/00 

FIELD: metallurgy.

SUBSTANCE: invention relates to hydrometallurgy and can be used to produce pure iron compounds, concentrates of nonferrous and noble metals from pyrite cinder, which are wastes of sulfuric acid production. Pyrite refuses are processed by means of hydrochloric-acid leaching of iron and non-ferrous metals. Pyrite cinder are preliminarily milled till fineness no more than 55 mcm. Hydrochloric acid leaching is carried out for 75–110 min at temperature 60–95 °C, at that quantity of hydrochloric acid to pyrite sting is maintained as ratio (2.8–3.2):(0.85–1.15). Produced cake is subjected to cyanidation by separator water in presence of coal and calcium oxide for 14–25 hours at temperature of 19–35 °C, after which pulp is separated from coal. Obtained pulp is separated into spent separator water and an iron-containing product. After cyanidation, coal undergoes desorption, and solution obtained as a result of desorption is supplied for electrolysis with subsequent re-melting of cathode residue.

EFFECT: technical result consists in increase of gold extraction degree from pyrite cinder (more than 70 %) and possibility of using obtained iron-containing product as charge in metallurgical production.

5 cl, 1 dwg