Iron control in medium temperature sulphide concentrate leaching

TECK通过其子公司CESL和Vale在实施中温硫化铜和硫化镍精矿浸出方面拥有商业利益。 “中温”用于描述在硫的熔点（119 ℃）以上但在硫变得高度粘稠的温度（159 ℃）以下操作的各种工艺。 Vale和TECK都在150 ℃下操作其中温浸出工艺。 在浸提期间，并且取决于各种工艺参数，铁可以作为赤铁矿、针铁矿、黄钾铁矾或其他羟基氧化物化合物沉淀，其可以或多或少是结晶的。 这些铁沉淀物最终作为工艺残留物被扣留。 赤铁矿是有利的沉淀物，因为它是最环境（化学）稳定的，并且在沉淀期间不添加/吸收同样多的铜、镍或其他溶液成分。 该提案描述了一个实验计划，以阐明在镍和硫化铜精矿的中温浸提过程中高度结晶的赤铁矿沉淀发生的条件。 建议两个博士。学生们在实验室规模上研究各种工艺参数，并采用经典和新开发的方法来确定赤铁矿沉淀的最佳条件。

TECK, through its subsidiary CESL, and Vale have commercial interests in the implementation of medium temperature copper and nickel sulphide concentrate leaching. "Medium temperature" is used to describe a variety of processes that operate above the melting point of sulphur (119C) but below the temperature where sulphur becomes highly viscous (159C). Both Vale and TECK operate their medium temperature leach processes at 150C. During leaching, and depending on various process parameters, iron may be precipitated as hematite, goethite, jarosite or other oxyhydroxide compounds, which may be more or less crystalline. These iron precipitates are eventually impounded as process residues. Hematite is the favored precipitate because it is the most environmentally (thermodynamically) stable and does not ad/absorb as much copper, nickel or other solution constituents during precipitation. This proposal describes an experimental plan to elucidate the conditions under which the precipitation of highly crystalline hematite occurs during medium temperature leaching of nickel and copper sulphide concentrates. It is proposed that two Ph.D. students study various process parameters at the lab scale and that they employ classical as well as newly developed methods to identify the optimal conditions for hematite precipitation.