钛白渣提纯制备电池级硫酸亚铁工艺技术研究

以某钛白粉生产企业副产钛白渣为原料,选用复合沉淀剂代替传统常用化学沉淀剂,采用一步沉淀法去除杂质,提纯制备电池级高纯硫酸亚铁产品,可作为磷酸铁锂生产原料,为钛白渣的利用提供了新途径。研究结果表明:选用氟化氢铵与还原铁粉按一定质量比配制的复合沉淀剂m(氟化氢铵)∶m(还原铁粉)=3.6∶1],控制反应条件:反应温度为60℃、反应时间为2h、沉淀剂用量为钛白渣处理量的2.67%(质量分数)、搅拌速度为300r/min、反应液中Fe2+浓度为1.37mol/L,最终得到产品纯度为99.98%,镁、钛杂质脱除率均达到99%以上,XRD结果表明产品为七水硫酸亚铁。

Study on preparation of battery-grade ferrous sulfate by purification of titanium white slag

Battery-grade high-purity ferrous sulphate product was purified and prepared by one-step precipitation method to remove impurities,taking the by-product titanium dioxide slag of a titanium dioxide production enterprise as rawmaterial and using composite precipitator instead of traditional chemical precipitator.It could be used as raw material for lithium iron phosphate production,thus providing a new way for the utilization of titanium white slag.Results showed that the compound precipitator was prepared by mixing ammonium hydrogen fluoride and reduced iron powder in a certain mass ratio of ammonium hydrogen fluoride to reduced iron powder（3.6:1）.The reaction conditions were as follows: reaction temperature was 60 ℃, reaction time was 2 h, amount of precipitator was 2.67%（mass fraction） of titanium white slag, stirring speed was 300 r/min and concentration of Fe²⁺in reaction solution was 1.37 mol/L .The final product purity was 99.98% and the removal rates of Mg and Ti impurities were both over 99%.XRD results showed that the product was ferrous sulfate heptahydrate.