Patent ID: 7615100
Filing Date: 2009-11-10
Classification: C22B,Y02P

Abstract:
1. A method of leaching zinc-bearing siliceous raw materials for the recovery of zinc, comprising: a) feeding a zinc-bearing siliceous raw material having a silica content of at least 15.5 wt %, based upon the weight of the zinc-bearing siliceous raw material, to a neutral leaching stage; b) decomposing easily soluble zinc compounds in said zinc-bearing siliceous raw material by contacting said zinc-bearing siliceous raw material with a neutral leaching solution to form a zinc-depleted precipitate and a zinc sulfate solution; c) separating said zinc sulfate solution from said zinc-depleted precipitate; d) subjecting said zinc sulfate solution to electrolysis to form elemental zinc; e) leaching said zinc-depleted precipitate with a stream of aqueous acid in an acidic leaching stage comprising a series of reactors that include a first reactor and a final reactor to convert silicates in said zinc-depleted precipitate to silica, comprising: