ABSTRACT

Although extensive research has been conducted on the effect of water chemistry in flotation, no single study exists which describes the effect of calcium and magnesium on the adsorption of starch onto the hematite in iron ore flotation. In this work flotation, entrainment, zeta potential, and settling tests were performed to determine the differing impact of calcium and magnesium in iron ore flotation. Results showed that magnesium is more detrimental to the flotation process at far lower concentrations than calcium. Performing flotation with 45 ppm of calcium resulted in a comparable impact on the process as performing flotation with 7 ppm of magnesium. While calcium promotes the adsorption of starch onto the hematite and reduces entrainment, past an optimal dosage magnesium is promoting the adsorption of starch to everything in solution causing low grades and recoveries. It was found that the starch adsorption onto the hematite is strongly impacted by the presence of magnesium, suggesting that starch is collecting the magnesium and self-flocculating prior to adsorption onto the hematite. Thus, the presence of magnesium can significantly reduce the flotation performance far more than what would be expected from calcium.

摘要

尽管对水化学对浮选的影响进行了广泛的研究，但没有一项研究描述钙和镁对铁矿石浮选中淀粉吸附到赤铁矿上的影响。在这项工作中，进行了浮选、夹带、zeta 电位和沉降测试，以确定钙和镁在铁矿石浮选中的不同影响。结果表明，镁在比钙低得多的浓度下对浮选过程更有害。用 45 ppm 的钙进行浮选对工艺产生的影响与用 7 ppm 的镁进行浮选产生的影响相当。当钙促进淀粉吸附到赤铁矿上并减少夹带时，超过最佳剂量的镁会促进淀粉对溶液中所有物质的吸附，从而导致低品位和回收率。发现淀粉在赤铁矿上的吸附受到镁的存在的强烈影响，这表明淀粉在吸附到赤铁矿上之前收集镁并自絮凝。因此，镁的存在可以显着降低浮选性能，远远超过钙的预期。