Abstract: To comprehensively utilize the iron in the slag of wet zinc smelting, test is made on the preparation of iron concentrate from the residue of neutral leaching of zinc calcine. Based on the conventional wet zinc smelting process, the high acid leaching is transformed into high temperature high acid reduction leaching process, making it possible for the iron to enter the solution in the form of ferrous iron, which is then precipitated by hydrogen peroxide and basic zinc carbonate. The test results indicate that the new process can obtain an iron concentrate grading over 51% from the leaching residue of zinc calcine, greatly reducing the final residue amount and meanwhile having no impact on the recovery of both zinc and indium.

Key words: Wet zinc smelting, Neutral leaching residue, High temperature high acid reduction leaching process, Iron precipitation