微细粒混合磁选精矿分级—分散浮选试验研究

针对东鞍山混合磁选精矿进行了预先分级—强化分散浮选试验研究，同时结合沉降试验、动电位测试、浊度测试等分析了分选效果改善的原因.在最优条件下分级—分散浮选闭路试验可获得精矿铁品位66.24%、铁回收率79.47%的浮选指标，与单一分散浮选的闭路试验相比，精矿铁回收率提高了4.47%.沉降试验和浊度测试表明，分散剂柠檬酸及粒度组成均会影响赤铁矿-石英混合矿的分散特性，柠檬酸主要吸附在赤铁矿表面从而增大矿粒间的静电斥力，优化粒度组成实现窄级别浮选则会进一步减弱矿粒间的非选择性团聚(罩盖)，为后续浮选分离创造有利条件，这也与DLVO理论及团聚动力学的分析结果基本一致.

Classification - Dispersion Flotation of Fine Mixed Magnetic Concentrate

The Donganshan mixed magnetic concentrate was separated through the pre-classification-enhanced dispersion flotation process， and the corresponding mechanism was investigated by the sedimentation test， zeta potential test， and turbidity measurement. Under the optimum conditions， a concentrate iron grade of 66.24% and iron recovery of 79.47% can be obtained by the closed circuit of classification-dispersion flotation， in which the recovery of concentrate iron is increased by 4.47% compared with the dispersion flotation results. The sedimentation and turbidity test indicate that the dispersant citric acid and particle size distribution can influence the dispersion state of the hematite-quartz mixture suspension. The adsorption of citric acid onto the hematite surface will increase the electrostatic repulsive force between the mineral particles. The narrow fraction flotation obtained by optimizing particle size distribution can decrease the detrimental hetero-aggregation， which is beneficial to the subsequent flotation separation， which is also supported by the DLVO theory and the agglomeration dynamics.