The possibility of applying a combined concentration and metallurgical method for processing low-grade and refractory copper–nickel ores was considered. The resulting rougher and scavenger flotation concentrate contained 2.07% nickel and 0.881% copper at a recovery of 85.44% and 89.91%, respectively. The concentrate was then roasted with ammonium sulfate, followed by aqueous leaching of clinker to dissolve nickel and copper. The roasting temperature, the ratio of concentrate to (NH₄)₂SO₄ in the mixture, and the temperature were varied. Based on the study findings, the following process conditions were found to be optimal: roasting temperature 400 °С, rougher concentrate to ammonium sulfate ratio 1:7, and grinding size −40 μm. A roasting temperature of 400 °C is significantly lower than the temperature applied in conventional pyrometallurgical processes. The possibility of collecting off-gases allows the reagent to be regenerated and makes the process even more cost-effective. End-to-end recovery into pregnant solution was 81.42% for nickel and 82.81% for copper. The resulting solutions can be processed by known hydrometallurgical methods.

中文翻译：

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硫酸铵在铜镍矿选矿中的可行性研究

考虑了采用浓缩和冶金相结合的方法来处理低品位和难熔铜镍矿的可能性。所得的粗浮选精矿和浮选精矿包含2.07％的镍和0.881％的铜，回收率分别为85.44％和89.91％。然后将浓缩物用硫酸铵焙烧，然后对熟料进行水浸以溶解镍和铜。焙烧温度，精矿与（NH ₄）₂ SO ₄的比例在混合物中，温度是变化的。根据研究结果，发现以下工艺条件是最佳的：焙烧温度为400°С，粗精矿与硫酸铵的比例为1：7，研磨尺寸为-40μm。400°C的烘烤温度明显低于常规火法冶金过程中的温度。收集废气的可能性使试剂得以再生，并使该过程更具成本效益。镍的端到端回收率为81.42％，铜为82.81％。所得溶液可以通过已知的湿法冶金方法进行处理。