Novel fluxing strategy of copper matte smelting and trace metals in E-Waste recycling
Min Chen, Katri Avarmaa, Pekka Taskinen, Lassi Klemettinen, Radosław Michallik, Hugh O’Brien, Ari Jokilaakso
Abstract
The distribution behavior of trace metals between copper matte and spinel-saturated iron silicate slags was investigated at 1250 °C and pSO2 of 0.25 atm at low silica concentrations. The experiments were conducted in magnetite (Fe3O4) spinel crucibles in controlled CO-CO2-SO2-Ar gas mixtures using a high-temperature equilibration-quenching technique. The concentrations of trace elements in matte, spinel, and slag were quantified by electron probe X-ray microanalysis and laser ablation-inductively coupled plasma-mass spectrometry. The trace metals (Ag, Ni, Co, and Sn) in all phases and their distribution coefficients were calculated as a function of matte grade. Results show that silver and nickel can be effectively recovered into matte, whereas cobalt and tin are predominantly deported into slag and gas phases, respectively. These results augment the fundamental thermodynamic data of trace metal distributions in copper smelting processes at low-silica fluxing practices.