Full-Text Search:
Home|Journal Papers|About CNKI|User Service|FAQ|Contact Us|中文
《中国地球化学学报(英文版)》 1993-01
Add to Favorite Get Latest Update

Partitioning and Hydrolysis of Nb and Ta and Their Implications with Regard to Mineralization

WANG YURONG GU FU YUAN ZIQIANG (Institute of Geochemistry,Academia Sinica,Guiyang,550002)  
K_2NbOF_5·H_2O and K_2TaF_7 were prepared through melting Nb_2O_5 and Ta_2O_5 respectively with KHF_2·2H_2O,followed by recrystallizing.The hydrolysis properties of K_2NbOF_5 and K_2TaF_7 were determined again by using a rapidly quench vessel.As temperature (from 250 to 550℃) and pressure (from 500 to 1500 bars) increase,the degree of hydrolysis of both K_2NbOF_5 and K_2TaF_7 will increase.Nb-and Ta-fluorine complex compounds are instable in supercritical aqueous fluids.The degree of hydrolysis of both K_2NbOF_5 and K_2TaF_7 decreases with increasing concentra- tion of HF,independent of the concentration of NaF. The partition coefficients of Nb and Ta between granitic melt and fluid phase are less than 0.15,i.e.,most of Nb and Ta are left in granitic melt.The partition coefficient of Ta is more dependent on the concentration of HF than that of Nb.The significance of hydrolysis in Nb-and Ta-mineralization is also discussed in the present paper.
Download(CAJ format) Download(PDF format)
CAJViewer7.0 supports all the CNKI file formats; AdobeReader only supports the PDF format.
©2006 Tsinghua Tongfang Knowledge Network Technology Co., Ltd.(Beijing)(TTKN) All rights reserved