Rotary Kiln-Hydrometallurgical Process

10.1 Anode slime is first roasted with sulfuric acid or for oxidation. The calcine is then leached to extract copper and silver is precipitated.  The  leach  residue  is  chlorinated  to  extract  gold  and separate silver. The products are qualified precious metals.The process is mature, involving a relatively small amount of revert and low investment. It is suitable for a treating capacity of no more than 2kt anode slime/a.

10.2Leaching with Downstream Processing by Top-blowing Rotary Converter (TBRC)

The process begins by pressurized leaching for Cu and Te removal, followed by TBRC as a substitute for the conventional lead bullion furnace and the cupel furnace, to directly produce Au-and-Ag-bearing anode sheets. The process has  multiple  advantages,  including  its  large  capacity, short process length, high valuable metal recoveries, and  low  environmental  impact.  It  is  suitable  for  a treating capacity of above 2kt anode slime/a.

10.3.Purely Hydrometallurgical Process

The process consists of autoclave Cu separation, chlorination leaching, Au reduction, Pb removal from chlorination residue, Ag leaching, Ag reduc- tion and casting, and Ag electrolysis. The process has low pollution level and high recovery, and generally requires low investment. It is suitable for a treating capacity of no more than 2kt anode slime/a.