›› 2007, Vol. 7 ›› Issue (5): 922-927.

• 反应与分离 •

### 常压下高浓度NaOH浸取铝土矿预脱硅

1. 北京化工大学化学工程学院
• 出版日期:2007-10-20 发布日期:2007-10-20

### Pre-desiliconization of a Bauxite Ore through Leaching by High Concentration NaOH Solution under Atmospheric Pressure

YANG Bo,WANG Jing-gang,ZHANG Yi-fei,ZHANG Yi

1. College of Chem.Eng.,Beijing University of Chemical Technology and Engineering
• Online:2007-10-20 Published:2007-10-20

Abstract: A leaching process for the pre-desiliconization of bauxite ore by high concentration NaOH solution under the atmospheric pressure was studied. The effects of leaching temperature, initial NaOH concentration, leaching time and mass ratio of alkali to ore on the leaching rates of Al2O3 and SiO2, and the ratio of aluminum to silicon in solid residue were investigated, and the kinetic equation was obtained. The results show that when the mass concentration of NaOH is 50%, the desiliconization temperature 135℃, mass ratio of alkali to ore 2.5 and the desiliconization time about 5~20 min, the ratio of aluminum to silicon of bauxite ore can be increased from 7.6 to 12, so as to meet the grade need of bauxite ore in Bayer process. The pre-desiliconization of bauxite ore can be realized by this process without physical processing. Compared with other chemical processing, the pre-desiliconization treatment can improve the grade of bauxite ore with the advantages of saving energy and reducing production costs, which may provide a new way of exploitation of mid-low grade bauxite ore.