ABSTRACT

Serpentine, a typically magnesium phyllosilicate gangue mineral, is often associated with chalcopyrite. In the process of flotation, serpentine is easy to get into the concentrate together with useful minerals, which seriously affects the quality of concentrate products. In this study, galactomannan (GM) was introduced for effectively separating chalcopyrite from serpentine with sodium butyl xanthate used as the collector. Its depression performance and adsorption mechanism were investigated through micro-flotation tests, zeta potential, FTIR, and XPS measurements. Micro-flotation test results showed that GM depressed serpentine more stronger than that of the chalcopyrite at a wide pH range of 3–8. An excellent separation of chalcopyrite and serpentine was achieved using GM as the depressant with a lower dosage of 40 mg/L, for which the flotation recovery of chalcopyrite was more than 80% and that of serpentine was close to 0. Zeta potential, FTIR, and XPS results illustrated that GM was chemically adsorbed on the serpentine surface through the interaction of the hydroxyl groups of GM with the Mg atoms on the serpentine surface. The formation of Mg(OH)₂ enhanced the hydrophilicity of serpentine and inhibited the adsorption of flotation reagents onto the serpentine surface, and thereby decreasing its floatability. Therefore, GM could be used as a potential depressant of serpentine owing to its high selectivity, low dosage, environment protection, and low cost.

摘要

蛇纹石是一种典型的页硅酸镁脉石矿物，通常与黄铜矿有关。在浮选过程中，蛇纹石容易与有用矿物一起进入精矿中，严重影响精矿产品的质量。本研究引入半乳甘露聚糖（GM），以丁基黄原酸钠为捕收剂，有效分离黄铜矿和蛇纹石。通过微浮选试验、zeta电位、FTIR和XPS测量对其抑制性能和吸附机理进行了研究。微浮选试验结果表明，在 3-8 的宽 pH 范围内，GM 抑制蛇纹石比黄铜矿更强。使用 GM 作为抑制剂以 40 mg/L 的较低剂量实现了黄铜矿和蛇纹石的出色分离，黄铜矿的浮选回收率超过 80%，蛇纹石的浮选回收率接近 0。Zeta 电位、FTIR 和 XPS 结果表明，GM 通过 GM 的羟基与蛇纹石表面上的镁原子。Mg(OH)的形成₂增强了蛇纹石的亲水性，抑制了浮选剂在蛇纹石表面的吸附，从而降低了其可浮性。因此，GM具有选择性高、用量少、环保、成本低等优点，可作为潜在的蛇纹石抑制剂。