HCl-柠檬酸配合浸出稀土氧化物的研究

Leaching Rare Earth Oxides by Hydrochloric Acid and Citric Acid

以白云鄂博稀土精矿-钙化焙烧-HCl浸磷后的矿物为原料,用HCl-柠檬酸混合溶液浸出稀土并对浸渣进行了场发射扫描电镜和能谱分析。考察了HCl-柠檬酸混合溶液浸出过程中HCl用量、柠檬酸用量、反应温度、反应时间、搅拌速度及液固比对稀土、氟浸出率的影响,并采用五因素正交回归试验对工艺参数进行了优化。结果表明:在HCl浓度3.0 mol·L-1,柠檬酸浓度0.3mol·L-1,反应温度40℃,液固比9∶1,反应时间40 min,搅拌速度300 r·min-1时,稀土的浸出率大于92.0%,氟的浸出率小于5.0%,实现了稀土与氟的分离。

The Bayan Obo rare earth concentrate-calcium roasting-dissolved phosphorus by hydrochloride minerals were used as raw materials.The rare earths were extracted with hydrochloric acid-citric acid mixed solution and FESEM,EDS were performed on the slag.The effects of hydrochloric acid dosage,citric acid dosage,reaction temperature,reaction time,stirring speed and liquid-solid ratio on the leaching rate of rare earth and fluorine in the mixed solution leaching process of hydrochloric acid and citric acid were investigated.The five-factor orthogonal regression test was used to optimize process parameters.The results showed that the HCl concentration of 3.0 mol·L-1,H3cit concentration of 0.3 mol·L-1,the reaction temperature of 40℃,liquid to solid of 9∶1,reaction time of 40 min and stirring speed of 300 r·min-1were optimum conditions.The leaching rate of rare earth is above 92.0%,whereas fluorine is less than 5.0%,which realized the separation of rare earth and fluorine.