离子型稀土矿渗流溶浸行为研究

Percolation Leaching Behavior of Ion-Adsorption-Type Rare Earth Ore

离子型稀土矿性质复杂,当前所采用的原地溶浸工艺适应性不强、影响因素较多,为揭示离子型稀土矿原地溶浸过程影响机制,探寻溶浸过程优化调控方法,本文以江西龙南足洞风化离子型稀土矿为研究对象,采用室内柱式溶浸法模拟原地溶浸工艺过程,开展离子型稀土矿溶浸过程影响规律研究,考察浸出过程各工艺因素对离子型稀土矿浸出效率的影响以及稀土原矿浸出前后的物质变化。研究结果表明,调控离子型稀土矿浸出过程原矿含水量4%、矿层高度43 mm,浸出剂浓度4%、浸出剂溶液p H值5.0、浸取过程固液比1.0∶0.8、浸取剂流速5 ml·min^-1为最佳浸出条件参数,在原矿REO总量为0.078%的情况下,可获得浸出率为92.87%的稀土母液,母液中稀土平均浓度为1.73g·L^-1,效果良好。稀土离子在浸出过程中与浸出剂的电解质NH＋4发生了离子交换反应,稀土离子被交换浸出,而阳离子电解质NH＋4则保留在浸渣中,整个浸出过程未生成其他新的物质,没有改变离子型稀土矿原有的晶型结构,不会影响稀土离子的渗流溶浸,有利于离子型稀土矿的绿色高效提取。

Ion-adsorption-type rare earth ore has complex properties. At present,in-situ leaching process lacks adaptability,and there are many influencing factors. In order to reveal impact mechanism of ion-type rare earth ore in-situ leaching process,and explore optimal control method,the indoor column leaching method was used to simulate in-situ leaching process,with the raw material of iontype rare earth ore from Longnan-Zudong of Jiangxi province. The technological factors of leaching process on the leaching efficiency of ion-type rare earth ore and infrared spectroscopic analysis before and after leaching were investigated. The results showed that the rare earth leaching rate was 92. 87%,and leaching liquid average concentration was 1. 73 g·L^-1,under the condition of the raw ore0. 078% for total REO,when optimum leaching condition parameters were as follows： the raw ore moisture content was 4%,ledge height was 43 mm,leaching agent concentration was 4%,leaching solution p H value was 5. 0,solid-liquid ratio of leaching process was 1. 0∶ 0. 8,velocity of leaching agent was 5 ml·min^-1 in the leaching process of ionic type rare earth ore. The ions exchange reaction happened between rare earth ions and electrolyte ion of leaching agent in the leaching process. Rare earth ions were exchanged,while electrolyte cation retained in the leach residue. The leaching process did not generate other new substances. There was no change of ionic type rare earth ore original crystal structure. It would not affect the percolation leaching of ion-type rare earth ore,which was beneficial to extraction of the rare earth ions.