Iron control in medium temperature sulphide concentrate leaching

泰克通过其子公司CESL和淡水河谷在实施中温硫化铜和镍精矿浸出方面拥有商业利益。“中等温度”用于描述在硫磺熔点(119摄氏度)以上但低于硫磺变得高度粘稠(159摄氏度)的温度以下的各种工艺。淡水河谷和泰克的中温浸出流程都是在150摄氏度下进行的。在浸出过程中，根据不同的工艺参数，铁可能会以赤铁矿、针铁矿、黄钾铁矾石或其他氢氧化合物的形式沉淀，这些化合物可能或多或少是结晶的。这些铁沉淀物最终作为工艺残留物被扣留。赤铁矿是最受欢迎的沉淀物，因为它在环境(热力学)上最稳定，在沉淀过程中不会吸收/吸收大量的铜、镍或其他溶液成分。 这项建议描述了一项实验计划，以阐明在硫化镍和铜精矿的中温浸出过程中，发生高度结晶的赤铁矿析出的条件。建议两名博士生在实验室范围内研究各种工艺参数，并使用经典方法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.