Lead is recovered from lead sulfide concentrates or mixed lead-zinc concentrates containing iron sulfide by forming a slurry of such concentrates in an aqueous medium containing ammonium sulfate and free ammonia, and introducing such slurry into a closed reaction vessel at a pressure not exceeding 30 psig. Oxygen also is introduced into such vessel to establish therein a partial oxygen pressure of at least a few psi, while vigorously agitating the slurry. The lead sulfide content of the concentrates thereby is converted to the form of substantially water-insoluble oxidic lead compounds, while any zinc sulfide present is dissolved. The slurry then is withdrawn from the reaction vessel and the insoluble residue is separated from the aqueous solution. The latter is treated for recovery of its zinc and ammonia content, and the residue is subjected to a froth flotation operation to form a concentrate containing substantially all the iron sulfide and a tailing containing the oxidic lead compounds. Lead is recovered from such tailing.
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