Hydrometallurgical recovery of lead from direct-to-blister copper flash smelting slag

Furnace slag from direct-to-blister smelting of copper concentrates contains 12-15% of copper and 2.5-4% of lead. In this form it cannot be deemed as waste material, and thus it is subjected to a high-temperature process of slag decopperization; after this, converting process is performed on the Cu-Pb-Fe alloy being the product of decopperization process in electric furnace. An interesting alternative to the presently used processing of flash smelting slag would be its hydrometallurgical processing and selective recovery of Pb and Cu. This paper presents the results of laboratory tests on flash smelting slag leaching with acetic acid solutions and acetic acid with urea additive. The experiments performed allowed to optimize the process parameters to such an extent that Pb content in the post-leaching sediment is practically equal to the value obtained through the high-temperature process performed in electric furnace.