摘要
The transformation behavior of ferrous sulfate was examined during hematite precipitation for iron removal in hydrometallurgical zinc.Specifically,the effects of the method used for oxygen supply(pre-crystallization or pre-oxidation of ferrous sulfate)and temperature(170–190℃)on the redissolution and oxidation–hydrolysis of ferrous sulfate were studied.The precipitation characteristics and phase characterization of the hematite product were investigated.The results showed that the solubility of ferrous sulfate was considerably lower at elevated temperatures.The dissolution behavior of ferrous sulfate crystals was influenced by both the concentrations of free acid and zinc sulfate and the oxydrolysis of ferrous ions.Rapid oxydrolysis of ferrous ions may serve as the dissolution driving force.Hematite precipitation proceeded via the following sequential steps:crystallization,redissolution,oxidation,and precipitation of ferrous sulfate.The dissolution of ferrous sulfate was slow,which helped to maintain a low supersaturation environment,thereby affording the production of high-grade hematite.
针对湿法炼锌赤铁矿法除铁过程中硫酸亚铁的转化行为,研究供氧方式(硫酸亚铁的预结晶或预氧化)和反应温度(170~190℃)对硫酸亚铁晶体再溶解-氧化水解的影响,考察赤铁矿产物的析出特性和物相组成。结果表明:硫酸亚铁在高温溶液中的溶解度明显降低;硫酸亚铁晶体的溶解行为受两个因素的控制:游离酸与硫酸锌浓度的变化和硫酸亚铁离子的氧化水解;亚铁离子的快速氧化是硫酸亚铁结晶重溶解的驱动力;赤铁矿的析出经历硫酸亚铁的结晶、再溶解、氧化和沉淀过程;硫酸亚铁的缓慢溶解有助于保持较低的过饱和度,有利于生产高品质的赤铁矿。
基金
Projects(51804146,51964029,51664030,51564030)supported by the National Natural Science Foundation of China
Project(2018YFC1900402)supported by the National Key Research and Development Program of China
Project supported by the Analysis and Testing Center of Kunming University of Science and Technology,China
