A potential industrial waste-waste co-treatment process of utilizing waste SO2 gas and residue heat to recover Co, Ni, and Cu from copper smelting slag

Xingbang Wan; Pekka Taskinen; Junjie Shi; Ari Jokilaakso

doi:10.1016/j.jhazmat.2021.125541

A potential industrial waste-waste co-treatment process of utilizing waste SO₂ gas and residue heat to recover Co, Ni, and Cu from copper smelting slag

J Hazard Mater. 2021 Jul 15:414:125541. doi: 10.1016/j.jhazmat.2021.125541. Epub 2021 Feb 26.

Authors

Xingbang Wan¹, Pekka Taskinen², Junjie Shi³, Ari Jokilaakso⁴

Affiliations

¹ Aalto University, School of Chemical Engineering, Department of Chemical and Metallurgical Engineering, PO Box 16100, FI-00076 Aalto, Finland. Electronic address: xingbang.wan@aalto.fi.
² Aalto University, School of Chemical Engineering, Department of Chemical and Metallurgical Engineering, PO Box 16100, FI-00076 Aalto, Finland. Electronic address: pekka.taskinen@aalto.fi.
³ School of Metallurgy, Northeastern University, Shenyang 110819, China; Key Laboratory for Ecological Metallurgy of Multimetallic Mineral (Ministry of Education), Northeastern University, Shenyang 110819, China. Electronic address: shijunjie@smm.neu.edu.cn.
⁴ Aalto University, School of Chemical Engineering, Department of Chemical and Metallurgical Engineering, PO Box 16100, FI-00076 Aalto, Finland. Electronic address: ari.jokilaakso@aalto.fi.

PMID: 33677318
DOI: 10.1016/j.jhazmat.2021.125541

Abstract

A potential industrial waste-waste co-treatment process was proposed and verified for the recovery of the valuable metals Co, Ni, and Cu from copper smelting slag by utilizing high temperature SO₂ off-gas. Sulfation roasting followed by water leaching under designed thermodynamic conditions was conducted to facilitate the selective formation of Co, Ni, and Cu sulfates while separating iron as oxide. Several parameters were studied such as roasting temperature, roasting time, the addition of Na₂SO₄, and leaching agent. Under the optimized sulfation roasting conditions (Gas flow: 500 mL/min, 5% SO₂ +20% O₂ +75% Ar; Roasting temperature: 650 °C; Roasting time: 4 h; Addition of Na₂SO₄: 30%) followed by water leaching (Leaching temperature: 80 °C; Leaching time: 5 h; solid to liquid ratio: 0.05 g/mL), the extraction yields of Ni, Co, and Cu were shown to reach 95.8% and 91.8%, 81.6%, respectively. Furthermore, the sulfation roasting - water leaching process was confirmed on lab-scale as a feasible and efficient way to recover valuable metals and the mechanism was determined and verified from the microstructural evolution. Finally, a potential environmentally friendly industrial process in terms of the energy flow and material flow was presented based on preliminary assessments for environmental benefits, economic benefits, and heat recovery.

Keywords: Circular economy; Environmentally friendly; SO(2); Sulfation roasting; Waste-waste co-treatment.

Publication types

Research Support, Non-U.S. Gov't