Recovery of zinc values from zinc and iron-bearing sulfide materials
AssigneeUniversity of Waterloo
InventorsDonald R. Spink, Jerry Y. Stein
Life of this patent
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Abstract
Iron-containing zinc sulfide concentrate is processed to recover zinc values therefrom. The concentrate is roasted to convert zinc sulfide and iron sulfide to their oxides while adequate sulfide-sulfur is retained to maintain the iron values in the ferrous state and thereby avoid ferrite formation. Zinc oxide and iron oxide values are recovered from the roast, simultaneously or sequentially, and residual zinc sulfide may be recycled to the roasting step.
Claims46
A process of treating iron-bearing zinc sulfide material, which comprises:
- contacting said zinc sulfide material with an oxidizing gas containing molecular oxygen at a temperature of at least about 900.degree. C. and below the sintering temperature of said material to effect desulfurization and to convert zinc and iron values contained in said material to oxide form while retaining residual sulfide-sulfur throughout said contacting step and in a partially-desulfurized product resulting therefrom in an amount such that at least about 90% of the iron values are present in the product in the form of ferrous oxide,
- subsequently recovering the zinc and iron values in oxide form from said partially-desulfurized product while retaining zinc values in sulfide form in said product, and
- returning, following said removal of said zinc and iron values in oxide form, the retaining zinc sulfide values to said contacting step.
The process of claim 13 wherein up to about 40% of said off-gas stream is recycled to the fluidized-bed contacting step.
Dependencies are inferred from the claim text.