Quantitative characterization and magnetic separation of copper pyrometallurgical tailing for molybdenum and copper pre-concentration and cleaning of environmentally hazardous elements

The comprehensive and harmless utilization of copper slag flotation tailing (CSFT) is the key to a waste -free and sustainable copper industry. Here, the mineralogy and molybdenum micro-dissemination in CSFT were quantified and characterized, and the feasibility of the comprehensive recovery of Mo, Cu and Fe resources from CSFT and hazardous elements fractionation behavior by magnetic separation was discussed. To investigate the occurrence and abundance of Mo in each phase, CSFT was classified into four types of phases, including magnetite/hematite (27.26%), silicate associations (43.37%), and metallic sulphides and oxides. Molybdenum distribution is closely related to magnetite/hematite-Fe and S. The magnetic separation results indicated that Mo and Cu were enhanced in magnetic products by 34-41 and 15-21%, respectively. Cleaner non-magnetic residues were found to decrease significantly by 37- 44, 58-60, and 11-19% for Cu, As, and Cr, respectively. Mineral fractionation was observed instead of chemical changes during magnetic separation. Despite a weak separation effect on magnetic and non-magnetic phases due to their close bonds and fine-disseminated minerals, the Fe-silicate associations without magnetic phases were well separated into non-magnetic residues. The enrichment of Ca, Mg and separation of an iron-silicate component in non-magnetic residues enhanced the cementitious prop-erty and allowed the development of more pathways of reutilization.(c) 2023 The Korean Society of Industrial and Engineering Chemistry. Published by Elsevier B.V. All rights reserved.