Behavior of SiO2 in the leaching process of alumina clinker with high concentration

It is essential for alumina production by alkaline process to know the behavior of minerals containing Al and Si in basic solution, and the behavior of SiO2 in the process of clinker leaching is an important portion. To study the behavior of SiO2 in the process of high concentration clinker leaching, experiments were carried out in home-made reactors. The results indicate that factors, such as temperature, time, Al2O3 concentration, as well as SiO2 concentration, have profound impact on the SiO2 and Al2O3 concentration of pregnant liquor during the high concentration leaching. However, sodium carbonate and free caustic soda concentrations have no remarkable effect on it, thus they are the secondary factors compared with Al2O3 concentration. The concentration of SiO2 in the pregnant liquor could be reduced to a lower level when the major effect parameters of this process are controlled properly.