摘要
风化壳淋积型稀土矿山粘土中常具有对浸矿剂离子或稀土离子的净吸附能力。假定净吸附形式为对浸矿剂NH_(4)^(+)的物理吸附和专性吸附以及对RE^(3+)的离子交换吸附,建立了考虑净吸附的风化壳淋积型稀土矿液-固萃取浸取模型,并计算讨论了不同净吸附类型对于稀土浸取过程和浸取效果的影响。结果显示,矿土中存在对NH_(4)^(+)的物理吸附和专性吸附均可导致浸出液中稀土峰值浓度降低;矿土对NH_(4)^(+)的净吸附能力增加还将导致浸矿剂消耗增加。通常半风化矿可净吸附离子相稀土,对于相同稀土品位的半风化原矿,净吸附RE^(3+)能力越强,母液中稀土穿透越为滞后,稀土穿透曲线拖尾现象也越严重,同时因净吸附稀土的矿土相当于提升了稀土品位而使硫酸铵投入/稀土产出比增大;半风化层中存在的稀土净吸附位点因可吸附前锋浸矿液中的RE^(3+)离子,理论上与已吸附了RE^(3+)离子的位点等效消耗浸矿剂。
Excess sites adsorbing leaching agent(NH_(4)^(+))or rare earth ions(RE^(3+))usually exist in the clay of weathered crust elution-deposited REminerals.Based on the assumption that the excess sites include 3 types:physical adsorption and specific adsorption of NHt and ion-exchange adsorption of RE^(3+),a liquid-solid extraction simulation method of RE leaching process was developed,and the effects of each type of adsorption are discussed on leaching process of RE according to model simulations.The results show that both the physical adsorption and specific adsorption of H_(4)^(+)will lower peak RE^(3+)concentration in leaching liquor;and the increase in excess NH adsorption ability of minerals will increase consumption of non-reusable leaching agent.Excess adsorption of ion-exchange RE^(3+)usually happens in partly weathered minerals,and for the minerals with the same RE grade,more excess adsorption sites of RE^(3+)will lead to a relatively more lagged breakthrough of RE^(3+)of leaching liquor and a more obvious peak tailing of leaching curves along with an increase of the ratio of(NH_(4)^(+))_(2)SO_(4)input to REO output due to the REO grade increase caused by the excess adsorption of RE^(3+);as for the parly-weathered minerals,excess adsorption sites can adsorb RE^(3+)in the pioneer leaching solution,and therefore they could consume leaching agent as much as those RE^(3+)already adsorbed.
作者
程福祥
吴声
廖春生
孙聆东
严纯华
Cheng Fuxiang;Wu Sheng;Liao Chunsheng;Sun Lingdong;Yan Chunhua(CREG(Beijing)Research Institute of RE Co.,Ltd,Bejing 100085,China;College of Chemistry and Molecular Engineering of Peking University,State Key Laboratory of Rare Earth Materials Chemistry and Applications,Beijing National Laboratory for Molecular Sciences,Beijing 100871,China)
出处
《中国稀土学报》
北大核心
2025年第4期772-787,共16页
Journal of the Chinese Society of Rare Earths
基金
国家自然科学基金项目(92262301)资助。
关键词
风化壳淋积型稀土矿
柱浸
液-固萃取模型
离子交换机理
净吸附
weathered crust elution-deposited rare earth minerals
column leaching
liquid-solid extraction model
ion exchange mechanism
excess adsorption
