The recovery of nickel and copper from nickel sulfide flotation tailings was studied by magnesium carbonate salt roasting followed by sulfuric acid leaching. Leaching was performed under atmospheric conditions using a gyratory water bath. The tailings material was roasted with and without magnesium carbonate at varying mass ratio (0.15 to 0.75), temperature (300 – 700 °C), and time (1 – 5 h). Subsequent leaching tests were performed using sulfuric acid at different concentrations (1 – 5 M). The influence of leaching time and temperature was investigated as well. The results after inductively coupled plasma optical emission spectroscopy analysis demonstrated that, under the optimum roasting and leaching conditions, about 98 % nickel was leached into solution while only approximately 38 % iron was present. Relatively high concentrations of other valuable metals such as copper, manganese and cobalt were also extracted into the leach solution. The salt roasting-acid leaching process consequently presents a feasible approach for selective recovery of valuable minerals from the sulfide tailings, thereby reducing downstream and purification costs.

中文翻译：

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研究使用盐焙烧和酸浸从硫化镍尾矿中选择性提取金属

通过碳酸镁盐焙烧后硫酸浸出研究了硫化镍浮选尾矿中镍和铜的回收率。在大气条件下使用回转水浴进行浸出。在不同的质量比（0.15 至 0.75）、温度 （300 – 700 °C） 和时间 （1 – 5 h） 下，对含和不含碳酸镁的尾矿材料进行焙烧。随后使用不同浓度 （1 – 5 M） 的硫酸进行浸出测试。还研究了浸出时间和温度的影响。电感耦合等离子体发射光谱分析后的结果表明，在最佳焙烧和浸出条件下，约 98% 的镍浸出到溶液中，而只有大约 38% 的铁存在。相对高浓度的其他有价金属，如铜、锰和钴也被提取到浸出液中。因此，盐焙烧-酸浸工艺提供了一种从硫化物尾矿中选择性回收有价值矿物的可行方法，从而降低了下游和净化成本。