Waste Management & Research 2007-10-01

Processing of copper converter slag for metal reclamation. Part I: Extraction and recovery of copper and cobalt.

Tong Deng, Yunhan Ling

Index: Waste Manag Res 25(5) , 440-8, (2007)

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Abstract

Clean processing of copper converter slag to reclaim cobalt and copper could be a challenge. An innovative and environmentally sound approach for recovering valuable metals from such a slag has been developed in the present study. Curing the slag with strong sulphuric acid, without re-smelting or roasting as practiced currently in the industry, render it accessible to leaching, and more than 95% of cobalt and up to 90% of copper was extracted together with iron by water leaching, leaving silica behind in a residue. The copper in the leach liquor was recovered by cementation with iron and the dissolved iron crystallized as ferrous sulphate monohydrate. The cobalt in the mother-liquor rich in iron was recovered by either cementation or sulphide precipitation. Operation variables in the new process were also investigated and optimized.