METHOD OF ACCOMPANYING RECOVERY OF OSMIUM FROM CHROMITES OF CHEMICAL TYPE Russian patent published in 2000 - IPC

FIELD: processing of chromites of chemical type. SUBSTANCE: chromites are subjected to oxidative roasting. The gas phase thus formed containing osmium tetraoxide is entrapped by means of solution containing alkali with concentration of 30-80 g/l and agent which convert anionic osmium complexes such as [OsO₄(OH)₂]^2-,[OsO₂(OH)₂]^2- and [OsO₃N]^- into cationic complexes such as [OsO₂(NH₃)]2+4

with concentration of 20-50 g/l. This agent is NH₄HCO₃. Osmium is recovered from solution by well known procedures. Method makes it possible to increase recovery of osmium from gas phase into absorbing solution reduce alkalinity of solution, to eliminate irreversible technological dispersion of osmium with technological products, to set up accompanying production of osmium in processing chemical type chromites, to increase yield of osmium due to using new type of osmium-containing stock to make chemical production ecologically safer and less harmful. EFFECT: more efficient recovery method. 5 ex, 1 tbl