Mechanism investigation and process optimization for oxygenenriched intensified converting of arsenic-lead-bearing copper matte

Speiss (Cu3As) and lead copper matte (Cu2S, PbS) are toxic wastes derived from the high-arsenic copper smelting process. This study proposed an oxygen-enriched bottom-blown intensified converting technique to extract Cu and remove Pb/As from the speiss and lead copper matte. The reaction mechanism and distribution behavior of Cu, Pb, and As in the converting process were clarified using thermodynamic calculation. The optimal converting conditions for Cu recovery and Pb/As removal were proposed and employed in industrial practice. The results show that blister copper, converting slag, and flue gas are produced from the oxygen-enriched bottom-blown intensified converting of the speiss and lead copper matte via oxidation and reduction stages at 1250 ℃. The concentrations of Cu and As in the blister copper are 93.94% and 3.85%, respectively. Approximately 60.42% of Cu from the speiss and lead copper matte is distributed to blister copper, while 27.43% of Cu is lost in the converting slag. The removal efficiency of Pb in the converting slag and dust reaches 82.77% and 17.22%, respectively. As removal efficiency into the converting slag and flue dust is 89.46%. The oxygen-enriched bottom-blown intensified converting technology shows excellent advantages in extracting Cu and removing Pb/As of the speiss and lead copper matte, providing an efficient approach for recycling high-arsenic complicated resources. © 2023 Central South University of Technology. All rights reserved.