METHOD OF GOLD RECOVERY FROM ORES, CONCENTRATES AND SLIMES Russian patent published in 2001 - IPC

FIELD: hydrometallurgy. SUBSTANCE: method includes cyanidation of initial raw materials by fractional supply of cyanide solution to finely divided pulp, gold sorption with use of synthetic sorbent containing strong and weak base functional groups in cascade of apparatuses with screen drainage and fixed volume of sorbent loading into apparatus, and supply in counterflow of pulp and sorbent with definite hourly flow of the latter, and subsequent desorption of gold from saturated sorbent. Cyanide concentration in pulp is maintained up to 1.5 g/l. Synthetic sorbent used in process contains functional groups in the form of quaternary, ternary, secondary and primary amine groups in the following ratio, wt.%: quaternary group, up to 2.5; ternary group, 10-25; secondary group, 45-60; primary group, 20-35. Gold sorption is effected from pulp with pH 8.0-10.8. Gold desorption is accomplished from saturated sorbent at temperature of 50-70 C with alkali-cyanide solutions, particularly, with solution containing 2-10 g/l of NaOH and 5-20 g/l of NaCN. Sorbents after recovery of gold from them are returned to cyaniding process. used for gold sorption is also sorbent whose grain size is determined from relation ρ_см> 2,5ρ_тв, where ρ_см is size of sorbent minimal grain, and ρ_тв is size of maximum grain of solid particle in ore pump, mm. For the fullest recovery of gold from ores with various gold content, sorption is carried out with sorbent load equalling 0.5-10% of apparatus volume and sorbent hourly flow of 0.03-2.00% of pulp flow. EFFECT: reduced time for sorbent regeneration by factor of 5-10, reduced consumption of chemical reagents, exclusion of high-temperature treatment of sorbent in its regeneration, refusal from use of acidproof equipment, higher safety of work for attending personnel due to absence of liberation of poisonous hydrocyanic acid. 7 cl, 5 tbl, 1 ex