离子型稀土矿无氨浸出研究

No Ammonia Leaching Study of Ionic Rare-earth Ore

为从源头上解决离子型稀土矿以硫酸铵溶液为浸矿剂所带来的氨氮废水污染问题,以赣南某离子型稀土矿为对象,开展了离子型稀土矿无氨浸出研究.首先通过探索试验比较了硫酸钾、硫酸钠、硫酸镁、硫代硫酸钠、硝酸钠、亚硝酸钠、氯化镁及A1、A2、A3、A4、A5与硫酸铵的浸矿效果,结果显示,A2 ～ A5可取得与硫酸铵较接近的浸出率,而其他8种非硫酸铵浸矿剂的浸出率都太低.在探索试验基础上,对A2～A5和硫酸铵进行了浸矿扩大试验,结果显示,A2、A3和A5均可获得与硫酸铵近乎相同的浸出率（分别为95.25％,95.01％,95.18％和95.05％）,但A3和A5的浸矿周期（分别为92和127 h）分别比硫酸铵的浸矿周期（58 h）增加了58.62％和118.97％,而A2的浸矿周期（48 h）比硫酸铵的浸矿周期缩短了17.24％.进一步对A2和硫酸铵所得浸矿扩大试验浸出液进行化学多元素分析,发现两者REO的浓度及杂质Fe、Al、Si、Ca的浓度都很接近.以上结果表明,A2不仅可取代硫酸铵实现离子型稀土矿的无氨浸矿,而且可较大幅度地缩短浸矿周期.

In order to solve the pollution of ammonia nitrogen wastewater stemmed from ionic type rare-earth ore leaching using ammonium sulfate solution as the reagents,research on ore leaching with no ammonia is carried out with an ionic type rare-earth ore,Jiangxi,as the research object.Ore leaching efficiency of potassium sulfate,sodium sulfate,magnesium sulfate,sodium thiosulfate,sodium nitrate,sodium nitrite,magnesium chloride and A1,A2,A3,A4,A5,and ammonium sulfate are compared in exploring experiment.The results show that A2 ～ A5 can have nearly the same leaching efficiency as ammonium sulfate,and the other 8 kinds of leaching reagents has lower leaching rate.Extending leaching experiments are carried out using A2 ～ A5 and ammonium sulfate as the leaching reagent,based on the exploring tests.The results indicated that,all of A2,A3 and A5 have nearly the same leaching rate as ammonium sulfate （95.25％,95.25％,95.01％ and 95.05％ respectively）,while leaching period of A3 and As（92,127 h respectively） are longer than that of ammonium sulfate （58 h） by 58.62％ and by 118.97％ respectively,while the leaching period of A2 （48 h） is shorter by 17.24％.Further chemical element analysis on leaching solution from extending test of A2 and ammonium sulfate as leaching reagent is conducted,finding that concentration of REO and impurities Fe,A1,Si,Ca is almost the same.In a word,A2 can not only replace ammonium sulfate to accomplish ore leaching of ionic type rare-earth without ammonia,but also greatly shorten the leaching period.