ABSTRACT

Anionic, cationic and cationic/anionic flotation is widely used in the concentration process for low-grade oxidized zinc ores. In the cationic flotation route, sodium silicate is used as a depressant for gangue minerals and amine as a collector for zinc minerals previously activated by sodium sulfide. However, the presence of polyvalent ions in aqueous solution can affect the surface properties of the various minerals and consequently, the selectivity of the process. This study evaluated the effect of Zn, Ca, and Mg ions, originated by the solubility of smithsonite and dolomite, on the surface properties of quartz and hematite. Microflotation tests showed the inefficiency of sodium silicate as a depressant for quartz in aqueous solution even when Zn, Ca, and Mg ions were not present. Activation of hematite by Zn ions was observed, impeding the separation of smithsonite and hematite (iron oxide). Results obtained from the microflotation and zeta potential tests were analyzed based on the speciation diagrams of the reagents and ions studied, as well as published studies.

摘要

阴离子、阳离子和阳离子/阴离子浮选广泛用于低品位氧化锌矿的选矿过程。在阳离子浮选路线中，硅酸钠用作脉石矿物的抑制剂，胺用作先前被硫化钠活化的锌矿物的捕收剂。然而，水溶液中多价离子的存在会影响各种矿物的表面性质，从而影响工艺的选择性。本研究评估了锌、钙和镁离子对石英和赤铁矿表面性质的影响，这些离子源自菱锌矿和白云石的溶解度。微浮选试验表明，即使不存在 Zn、Ca 和 Mg 离子，硅酸钠作为水溶液中石英的抑制剂也是无效的。观察到锌离子激活赤铁矿，阻碍菱锌矿和赤铁矿（氧化铁）的分离。根据所研究的试剂和离子的形态图以及已发表的研究，分析了从微浮选和 zeta 电位测试获得的结果。