The purification of mother liquor containing sodium aluminate by using desilication agent and the preparation of high pure pseudo-boehmite and gamma alumina are reported. The sodium aluminate in the mother liquor coming from Shanxi Aluminium Plant is treated with home-made desilication agent

the ratios of SiO2/Al2O3 and Fe2O3/Al2O3 in treated-solution are below 0.01%. The pseudo-boehmite is obtained with buffer solution deposition in which ammonia gas acts as a circulating medium. The specific surface area of pseudo-boehime powder reaches up to 300m28226;g-1 and pore volume reaches about 0.7ml8226;g-1.The content of sodium in pseudo-boehime is below 0.005% after treating the pseudo-boehime with a sodium removal agent.The quality of this product is comparable to the SB powder made in Germany.Gamma alumina with a larger specific surface area and pore volume is obtained by temperature programmed calcination of pseudo-boehmite.