复杂稀有金属矿稀土回收新工艺

研究一种从不能用物理选矿法有效富集稀土的复杂稀有金属矿中回收稀土的工艺。原矿在酸矿质量比为1.2时于400℃酸化90min,然后在液固比5∶1、90℃浸出120min,稀土浸出率可以达到85.64%。浸出液经氧化、中和除杂后,按稀土理论用量1.2倍添加草酸。得到的草酸稀土沉淀在950℃煅烧60min,可获得REO含量92.4%的氧化稀土产品,全流程稀土总回收率为71.32%。

New Process of Rare Earth Recovery from Complex Rare-Metal Ores

A new rare earth recovery process from complex rare-metal ore,whose rare earth was difficult to enrich by physical beneficiation,was investigated.The results show that the leaching rate of rare earth reaches 85.64% on the optimum conditions: the raw ore is acidulated at 400 ℃ for 90 min with the mass ratio between acid and ore of 1.2,then leached at 90 ℃ for 120 min with the solid/liquid ratio of 5∶1.The leaching liquor is purified through oxidation and neutralization treatment,then adding oxalic acid according to 1.2 times of the rare earth theory dosage.The oxalic rare earth precipitates are roasted at 950 ℃ for 60 min,so the rare earth oxide(REO) products with REO content of 92.4% can be obtained,and the total recovery of rare earth is 71.32%.