Recent Trends in the Processing of Enargite Concentrates
Kawatra, S. Komar
The copper industry is witnessing great interest in the development and utilization of copper-arsenic deposits. While most plants tend to use traditional processing technologies, the depletion of conventional copper ores has created competition for designing and implementing new process alternatives for the treatment of copper-arsenic ores containing minerals such as enargite, luzonite and tennantite. However, the downstream processing of enargite-containing concentrates represents a major metallurgical challenge. An important consideration in all enargite processing options is the deportment and stabilization of arsenic in a benign form that meets current and anticipated environmental regulations. Smelters are subject to penalties on high arsenic-bearing copper concentrates. While reductive roasting can drive-off the arsenic from enargite concentrates to an acceptable level suitable for smelting (<0.5 wt.%), this option has generally been viewed as unacceptable due to environmental conflicts and the lack of a market for arsenic trioxide. The lack of a suitable pyrometallurgical option has led to several proposed hydrometallurgical treatments of enargite concentrates. Hydrometallurgical options include either selective arsenic dissolution to produce a clean copper concentrate or collective leaching of copper and arsenic. Both options with various conditions and lixiviants are discussed and evaluated. In this review, alkaline sulfide leach (ASL), sulfate and chloride based leach systems, high temperature pressure oxidation (HTPOX), sodium hypochlorite leach, bio-leach/oxidation, nitrogen species catalyzed pressure oxidation (NSC), Cominco Engineering Services Limited (CESL), Intec, HydroCopperTM and Fluobor® processes are outlined. Pyrometallurgical process strategies have also been briefly reviewed. Among all process options, alkaline sulfide leach, high temperature pressure oxidation, Fluobor® and reductive roasting processes are given special attention with specific flowsheets for enargite concentrates discussed.
M. S. Safarzadeh et al., "Recent Trends in the Processing of Enargite Concentrates," Mineral Processing and Extractive Metallurgy Review, Taylor & Francis, Oct 2012.
The definitive version is available at http://dx.doi.org/10.1080/08827508.2012.723651
Materials Science and Engineering
Keywords and Phrases
Arsenic; Enargite; Hydrometallurgy; Leaching; Pyrometallurgy; Stabilization
Article - Journal
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