Recovery of Cu-Fe-S matte from electroplating sludge via the sulfurization-smelting method. Issue 5 (October 2022)

• Record Type: Journal Article
• Authors: Wang, Hong-Yang; Li, Yu; Jiao, Shu-Qiang; Zhang, Guo-Hua
• Is Part Of: Journal of environmental chemical engineering. Volume 10:Issue 5(2022)
• Publication Date: 2022-10
• Subjects: Electroplating sludge -- Copper matte -- Vitrification -- Sulfurization reaction; Chemical engineering -- Environmental aspects -- Periodicals; Environmental engineering -- Periodicals; Chemical engineering -- Environmental aspects; Environmental engineering; Periodicals; 660.0286
• DOI: 10.1016/j.jece.2022.108266
• Languages: English
• ISSNs: 2213-2929

Abstract

Abstract: In this work, Cu-Fe-S matte was prepared from the electroplating sludge (ES) via the sulfurization-smelting process. The recovery extents of Cu and Fe are 99.60% and 10.07%, respectively, demonstrating that the selective recovery of Cu was achieved using this process. The recovered matte (70%Cu-11%Fe-S) can be utilized as the raw material to produce pure Cu. Two kinds of ES (sulfur-containing electroplating sludge and phosphorus-containing electroplating sludge), with the main compositions of CaSO4 -CuO-Fe2 O3 (SES) and CuO-CaF2 -CaO-P2 O5 (PES), were mixed and co-reduced by carbon at 1000 ℃. At this stage, the CaSO4 in SES was utilized as the sulfurization agent to sulfurize the CuO to Cu5 FeS4 . The generated Cu5 FeS4 was then separated from slag via smelting at 1500 ℃. During the smelting process, SiO2 was added as flux, and two immiscible phases, liquid Cu-Fe-S matte and molten slag, were formed. After cooling, the Cu-Fe-S matte with the main phase of Cu5 FeS4, as well as the vitrified slag, was obtained. The leaching concentrations of toxic elements Cu, P, and F of slag were lower than the thresholds, and thereby, this slag can be safely used as the construction material. Graphical Abstract: ga1 Highlights: High-grade Cu matte was prepared from electroplating sludge (ES) by using the sulfurization-smelting method. CaSO4 in the ES provided the sulfur source for the sulfurization reaction. Cu5 FeS4 was formed when the ES was pre-reduced by carbon at 1000 °C. Harmless slag was obtained via the high-temperature vitrification method.