Simultaneous recovery of arsenic and copper from copper smelting slag by flotation: Redistribution behavior and toxicity investigation

Abstract

Recovering arsenic from copper smelting slag (CS) into concentrate by flotation, along with copper, can effectively manage arsenic contamination and recover substantial metal resources. The present work selected a combined collector for the simultaneous recovery of arsenic and copper based on the mineral morphology of the critical elements in CS. The redistribution behavior of arsenic and copper during flotation and the toxicity characteristics of CS and its flotation products were investigated using multidisciplinary characterization techniques. The results show that the collection of loellingite and copper matte from CS is crucial for the recovery of arsenic and copper. First-principles calculations indicate that O-isopropyl ethylthiocarbamate possesses a strong capacity to collect loellingite, and flotation experiments confirm that mixing O-isopropyl ethylthiocarbamate with sodium butyl xanthate maximizes the recovery of arsenic and copper. Unrecoverable arsenic and copper exist either encapsulated within the gangue as fine micron-sized mineral particles or dissolved into glassy silicates. Environmental hazard and economic assessments reveal that the simultaneous recovery of arsenic and copper by flotation not only reduces the leaching toxicity of the tailings, but also brings substantial economic benefits. Overall, this study provides a novel perspective on the reclamation of CS and the mitigation of contamination risks associated with CS flotation tailings, contributing to the sustainability of the copper industry.