An Update to “Recent Trends in the Processing of Enargite Concentrates”.

An update is presented to the paper “Recent trends in the processing of enargite concentrates” by Safarzadeh, Moats, and Miller (2014). Publications which were not included in the initial review paper, primarily to avoid redundancy, are presented and discussed here. Thus, roasting, atmospheric acidic and alkaline leaching, the dissolution of enargite in low-melting point salts, bioleaching, and pressure leaching are presented. For the first time, the modified phase stability (Kellogg) diagram and the Eh-pH diagram for the Cu-As-S system including sinnerite (Cu6As4S9) have been established. According to the results from different treatment options discussed in our earlier review and also in this paper, it is evident that the most recent research activities for the treatment of enargite concentrates are centered around roasting, alkaline sulfide leaching, and high temperature pressure oxidation. Taking into account the advantages and disadvantages of the mentioned processing options, and the numerous preliminary experiments performed, the acid bake-leach process has been identified and is being studied at the University of Utah. It has been found that enargite transforms to water-soluble copper sulfate, arsenic trioxide and elemental sulfur by sulfuric acid baking of enargite at 200°C, with less than 1% of the arsenic being released to the gas phase. This process strategy provides a new possibility for the treatment of enargite concentrates. [ABSTRACT FROM PUBLISHER]