METHOD OF PROCESSING OF PERSISTENT GOLD-ARSENIC ORES AND CONCENTRATES Russian patent published in 2005 - IPC

FIELD: hydrometallurgy; methods of extraction of gold from persistent gold-arsenic ores and concentrates.

SUBSTANCE: the invention is pertaining to the field of hydrometallurgy and is used for extraction of gold from persistent gold-arsenic ores and concentrates of different compositions, in which the fine-dispersed gold is contained in the sulfide minerals and is unavailable in case of application of traditional industrial cyanide process. The method of processing of persistent gold-arsenic ores and concentrates of a BIOS-M includes a flotation concentration of the source raw, washout of the pulp of the produced concentrate from cyanides up to concentration of NaCN - 0.05-0.1 mg/l, the concentrate bio-oxidation, a two-stage neutralization of the products of bio-oxidation, a sorption cyanidation and a desorption of gold and silver. The bio-oxidation process is conducted in four stages at the temperature of 37-42°C. At the bio-oxidation process the pulp pH on the second stage is kept on the level of 1.90-1.85, on the third stage - on the level of 1.8-1.82 with the help of feeding of the source concentrate or a crushed limestone, or lime. Before the flotation concentration of the source raw there may be conducted its gravity concentration. For optimization of the process a part of the pulp with an active biomass of bacteria from the second and third stages of bio-oxidation of the concentrate is fed back in the first stage of bio-oxidation. The technical result is a significantly increased speed of the process.

EFFECT: the invention ensures a significant increase of speed of the process.

4 cl, 1 dwg, 3 tbl