Cyclic process for reprocessing metal-containing residues

摘要

The disposal of metal-containing residues has hitherto been predominantly by deposition in a landfill, incineration or thermometallurgical processes with considerable pollution of the environment and only low recovery of the metallic materials. The new process should enable, in a cyclic process, metals such as copper, silver, gold and platinum, which are present in combination with other components, including toxic components, to be recovered and at the same time concentrates or residual residues which are non-problematical to process further or to dispose of to be obtained. For this purpose, the residue material is first treated with sulphuric acid to remove base metals. Subsequently, copper, silver and mercury are dissolved using peroxodisulphuric acid/peroxodisulphate solution and deposited electrolytically with simultaneous regeneration of the solution used. In the presence of noble metals, these are subsequently dissolved using chloride-containing peroxodisulphuric acid/peroxodisulphate solution, deposited electrolytically and the remaining solution is again used in the cyclic process. The remaining residue material can, after being treated again with peroxodisulphuric acid/peroxodisulphate solution and washing, be reused or deposited in a landfill.