| 摘要 |
<p>FIELD: nonferrous metallurgy, more particularly hydrometallurgical treatment of feedstock containing non-ferrous and noble metals. SUBSTANCE: silver-containing waste is created with neutral (pH 6-8) solution of sodium thiosulfate at concentration of 0.1-2.5 mole/l, preferably 0.25-1.0 mole/l, at 40-80 C and solid-liquid phase ratio is maintained for 10-120 minutes. On completion of the leaching process, the solution is collected by filtration, solver sulfide concentrate is precipitated from the filtrate at 20-40 C by addition sodium sulfide solution to attain redox potential of 450-550 mV and Me: S ratio of (1.2-1.8):1 wherein Me is Ag, Cu, Pb, Au. The resulting concentrate is separated which is then used as circulating solution and directed to leaching stage. The process makes it possible to attain 66-99% degree of recovery of silver into solution, selectively separate silver from the bulk of heavy non-ferrous and noble metals and recover it as 5-42% silver-containing concentrates without using toxic and aggressive reactants and employing special corrosion-resistant equipment. EFFECT: more efficient recovery process. 3 cl, 5 tbl</p> |
