Dissolution behaviors of Ta_2O_5,Nb_2O_5 and their mixture in KOH and H_2O system  

作　　者：王晓辉 郑诗礼 徐红彬 张懿 

机构地区：[1]National Engineering Laboratory for Hydrometallurgical Cleaner Production Technology,Key Laboratory of Green Process and Engineering,Institute of Process Engineering,Chinese Academy of Sciences [2]Graduate School of Chinese Academy of Sciences

出　　处：《Transactions of Nonferrous Metals Society of China》2010年第10期2006-2011,共6页中国有色金属学报（英文版）

基　　金：Project(2009AA06Z103) supported by the National High-tech Research and Development Program of China;Project(51004094) supported by the National Natural Science Foundation of China;Project(2007CB613501) supported by the National Basic Research Program of China

摘　　要：The dissolution behaviors of Ta2O5,Nb2O5 and their mixture in KOH and H2O system were investigated.A L9(34) orthogonal design was used to study the effects of reaction temperature,mass ratio of KOH to Ta2O5,and reaction time on the dissolution rate of tantalum.It was found that the effect of reaction temperature on the dissolution rate of tantalum was much greater than that of the other factors.The results of factorial experiments showed that Ta2O5 was mainly transformed into insoluble potassium tantalate at low temperature(350 ℃) and transformed into soluble potassium tantalate at high temperature(450 ℃).The insoluble potassium tantalate was analyzed by XRD,which was proved to be KTaO3.Differently,almost all Nb2O5 was transformed into soluble potassium niobate at 350-450℃.As for the mixture of Ta2O5 and Nb2O5,the dissolution rate of tantalum increased and the dissolution rate of niobium decreased as an interaction existed between niobium and tantalum.And increasing the mole ratio of Nb2O5 to Ta2O5 in the mixture was beneficial to the dissolution of both Ta2O5 and Nb2O5.In addition,the mechanism of the interaction between niobium and tantalum was also investigated through phase and chemical analysis.The dissolution behaviors of Ta2O5,Nb2O5 and their mixture in KOH and H2O system were investigated.A L9（34） orthogonal design was used to study the effects of reaction temperature,mass ratio of KOH to Ta2O5,and reaction time on the dissolution rate of tantalum.It was found that the effect of reaction temperature on the dissolution rate of tantalum was much greater than that of the other factors.The results of factorial experiments showed that Ta2O5 was mainly transformed into insoluble potassium tantalate at low temperature（350 ℃） and transformed into soluble potassium tantalate at high temperature（450 ℃）.The insoluble potassium tantalate was analyzed by XRD,which was proved to be KTaO3.Differently,almost all Nb2O5 was transformed into soluble potassium niobate at 350-450℃.As for the mixture of Ta2O5 and Nb2O5,the dissolution rate of tantalum increased and the dissolution rate of niobium decreased as an interaction existed between niobium and tantalum.And increasing the mole ratio of Nb2O5 to Ta2O5 in the mixture was beneficial to the dissolution of both Ta2O5 and Nb2O5.In addition,the mechanism of the interaction between niobium and tantalum was also investigated through phase and chemical analysis.

关 键 词：TA2O5 NB2O5 KOH dissolution behavior mechanism SOLID-SOLUTION 

分 类 号：TF841[冶金工程—有色金属冶金]