Hydrothermal conversion of Ti-containing minerals in system of Na20-Al2Oa-SiO2-CaO-TiO2-H2O

Titanium has a great effect on the digestion of bauxite in the Bayer process because it reacts readily at high temperatures in alkaline sodium aluminate solution. Under this consideration, the hydrothermal conversion of Ti-containing minerals in the system of Na2O-Al2O3- SiO2-CaO-TiOz-H2O with incre...

Full description

Saved in:
Bibliographic Details
Published in稀有金属：英文版 no. 6; pp. 495 - 501
Main Author Yan-Xiu Wang Ting-An Zhang Guo-Zhi Lv Xiao-Feng Zhu Wei-Guang Zhang Li-Qun Xie
Format Journal Article
LanguageEnglish
Published 2016
Subjects
CaTiO3
含钛矿物
晶体结构
水热转化
热力学分析
转化系统
铝酸钠溶液
锐钛矿型
Online AccessGet full text

Cover

More Information
Summary:Titanium has a great effect on the digestion of bauxite in the Bayer process because it reacts readily at high temperatures in alkaline sodium aluminate solution. Under this consideration, the hydrothermal conversion of Ti-containing minerals in the system of Na2O-Al2O3- SiO2-CaO-TiOz-H2O with increased temperatures was studied based on the thermodynamic analysis and systematic experiments. The results show that anatase converts to AlaTi2SiO12 at low temperatures （60-120℃）, which is similar to anatase in crystal structure. As the temperature continues to rise, Al4Ti2SiO12 decomposes gradually and converts to Ca3TiSi2（Al2Si0.5Ti0.5）O14 at 200 ℃ When the temperature reaches 260℃, CaTiO3 forms as the most stable titanate species for its hexagonal closest packing with O^2- and Ca^2＋. The findings enhance the under-standing of titanate scaling in the Bayer process and clarify the mechanism of how additive lime improves the digestion of diaspore.
Bibliography:Hydrothermal conversion; Ti-containing minerals; Bayer process; Anatase; Aluminosilicate
Titanium has a great effect on the digestion of bauxite in the Bayer process because it reacts readily at high temperatures in alkaline sodium aluminate solution. Under this consideration, the hydrothermal conversion of Ti-containing minerals in the system of Na2O-Al2O3- SiO2-CaO-TiOz-H2O with increased temperatures was studied based on the thermodynamic analysis and systematic experiments. The results show that anatase converts to AlaTi2SiO12 at low temperatures （60-120℃）, which is similar to anatase in crystal structure. As the temperature continues to rise, Al4Ti2SiO12 decomposes gradually and converts to Ca3TiSi2（Al2Si0.5Ti0.5）O14 at 200 ℃ When the temperature reaches 260℃, CaTiO3 forms as the most stable titanate species for its hexagonal closest packing with O^2- and Ca^2＋. The findings enhance the under-standing of titanate scaling in the Bayer process and clarify the mechanism of how additive lime improves the digestion of diaspore.
11-2112
ISSN:1001-0521
1867-7185