硫酸铵浸取离子型稀土时柠檬酸加量及pH值对稀土和铝浸取率的影响研究  

Study on the Influence of Citric Acid Dosage and pH Value on the Leaching Rate of Rare Earth and Aluminum during Ammonium Sulfate Leaching of Ion-Type Rare Earth

作　　者：蔡隆祥 CAI Long-xiang(School of Civil and Surveying and Mapping Engineering,Jiangxi University of Science and Technology,Ganzhou 341000,China)

机构地区：[1]江西理工大学,土木与测绘工程学院,江西赣州341000

出　　处：《世界有色金属》2024年第19期193-195,共3页World Nonferrous Metals

摘　　要：利用柠檬酸根与稀土和铝离子的络合反应及柠檬酸盐对pH值的缓冲作用,提高稀土浸出率并降低铝的浸取率。本研究在硫酸铵和柠檬酸三铵用量不变的条件下,通过改变柠檬酸用量和pH值,进行柱浸实验。基于稀土浸出液中稀土离子和铝离子的浓度及pH值变化,研究柠檬酸用量对稀土和铝浸出率的影响及其与pH值的关系。通过Visual MINTEQ软件模拟pH=3~6时,RE^(3+)、Al^(3+)、C_(6)H_(5)O_(7)^(3-)和SO_(4)^(2-)的分布,讨论其影响机制。结果表明,随柠檬酸用量降低,浸出液中RE^(3+)和Al^(3+)的浓度均下降,但浸出稀土总量与铝总量比值呈峰值变化,最大可达到4.45;因为在pH=4.0~4.5时,有90%以上的稀土离子与柠檬酸根离子生成稳定的络合物,提高稀土浸出率,0~10% Al^(3+)水解生成Al(OH)_(3)沉淀,降低杂质浸出率。Utilizing the chelation reaction between citrate ions and rare earth and aluminum ions,as well as the buffering effect of citrate salts on pH value,the leaching rate of rare earth is increased while the leaching rate of aluminum is decreased.In this study,under constant amounts of ammonium sulfate and trisodium citrate,column leaching experiments were conducted by varying the dosage of citric acid and pH value.Based on the changes in the concentrations of rare earth ions and aluminum ions,as well as the pH value in the leaching solution,the effect of citric acid dosage on the leaching rates of rare earth and aluminum,and its relationship with pH value,were investigated.The distribution of RE^(3+),Al^(3+),C_(6)H_(5)O_(7)^(3-)and SO_(4)^(2-)was simulated using Visual MINTEQ software at pH values ranging from 3 to 6 to discuss the influencing mechanism.The results showed that as the citric acid dosage decreased,the concentrations of RE^(3+)and Al^(3+)in the leaching solution both decreased.However,the ratio of the total leached rare earth to the total leached aluminum exhibited a peak value,reaching a maximum of 4.45.This is because at pH values between 4.0 and 4.5,over 90%of the rare earth ions formed stable complexes with citrate ions,enhancing the leaching rate of rare earth.Meanwhile,0 to 10%of Al^(3+)hydrolyzed to form Al(OH)_(3) precipitates,reducing the impurity leaching rate.

关 键 词：柠檬酸盐 离子型稀土 络合反应 Visual MINTEQ pH 

分 类 号：TD865[矿业工程—金属矿开采]