针铁矿法从氯化稀土料液中除铁研究

Study on Removal of Iron from Rare Earth Chloride Solution by Goethite Method

采用针铁矿法从氯化稀土料液中除铁,研究了pH、反应温度、陈化时间、加料速度以及加入晶种等因素对除铁效果的影响。结果表明,在pH=3.5、反应温度85℃,陈化时间120 min,加料速度25 mL/min的条件下,除铁率和稀土损失率分别为99.44%和3.40%。加入晶种0.1 g的条件下,导致部分或全部二次成核,缩短或省去了成核诱导期,相比于未加晶种时的陈化时间缩短了60 min,且最高除铁率达99.62%。针铁矿法沉铁渣为晶型良好的β-FeOOH晶体,过滤性能优于中和水解法的沉铁渣。针铁矿法除铁能应用于稀土湿法冶金中,除铁效果良好。

Goethite method was applied to remove iron from solution of rare earth chloride.Effects of pH value,reaction temperature,aging time,feeding speed,and crystal seed addition on iron removal were studied.The results show that iron removal rate and rare earth loss rate is 99.44% and 3.40% respectively under the conditions including pH value of 3.5,reaction temperature of 85℃,aging time of 120 min,and feeding rate of 2.5 mL/min.Addition of 0.1 g seed results in partial or total secondary nucleation,which shortens or omits nucleation induction period Compared with aging time without seed addition,aging time is shortened by 60 min,and the highest iron removal rate is 99.62%.The iron settling slag obtained by goethite method is β-FeOOH crystal with good crystal shape,and its filtration property is better than that of neutralization hydrolysis method.Goethite method to remove iron can be used in rare earth hydrometallurgy with good effect of iron removal.