TBP从硫酸体系中萃取铌的基础研究  

Fundamental study of niobium extraction from sulfuric acid system by TBP

作　　者：李天爽[1,2] 顾珩[2] 刘勇[2] 

机构地区：[1]中南大学冶金与环境学院,湖南长沙410083 [2]广州有色金属研究院稀有金属分离与综合利用国家重点实验室,广东广州510650

出　　处：《材料研究与应用》2015年第3期172-177,共6页Materials Research and Application

摘　　要：探索了TBP在无氟硫酸体系中萃取铌的相关影响因素，并通过引入草酸改善TBP在低酸萃取效率低的问题．主要研究了硫酸浓度、硫酸盐浓度、混相时间及多级错流萃取对铌萃取率的影响．结果表明：铌萃取率随硫酸浓度升高而增加，并在酸度为8-9mol／L时稳定在70％左右；硫酸盐对萃取有抑制作用；在混相时间为1min时，萃取反应即可完成；在多级错流萃取试验中，高酸度条件下三级错流萃取可萃取大部分铌，但是低酸度条件下效果不理想，引入草酸可改善TBP对铌的萃取低的问题：用草酸溶液反萃有机相中的铌，两级反萃可反萃98％以上的铌．Sulphuric extraction process is suitable for niobium ores which are at low grade or associated with many other metals.But the research focused on the niobium extraction in sulfuric acid （without fluoric） system was incomplete. So,we studied the factors affected the extraction of niobium by TBP, adding oxalic into solution to get a better extraction of niobium. TBP and the solution containing niobium was mixed and shaked for several minutes ,analysed the niobium concentration in the solution.It was found that the extraction of niobium by 100% TBP in the sulfuric solution is getting better when the H2SO4 concentration increase. When the acid concentration reached 8-9 mol/L,the extraction nearly remain stable. Sodium sulfate has a negative effect on the extraction.The extraction can accomplish within one minute. There was little niobium in the solution after repeated extraction using TBP three times at high sulphuric acid concentration.However, the niobium concentration in the second and the third extracted organic phase is relatively low. TBP can also extract the niobium complex formed with oxalic acid, the extraction increase when the H2SO4 concentration increase. So, by adding oxalic acid into the solution to transform niobium into oxalic complex,the extraction at low sulphuric acid concentration is improved. The niobium extracted in the organic phase can be stripped by oxalic acid.After stripped by oxalic acid twice ,the concentration in the organic phase is negligible.

关 键 词：TBP 萃取 铌 H2SO4 

分 类 号：TF841.6[冶金工程—有色金属冶金]