Abstract:Silica residue was used as crystal seed for normal-pressure desilication in desilication process of sintering. The desilication effects were investigated with respect to different alumina concentration, seed additive amount and αk of raw liquor. Desilication effects were compared with those of Bayer red mud as crystal seed. The results show that the silica index can be improved up to over 300 under the following conditions including Al2O3 concentration of raw liquor of 110~125 g/L, αk=1.40~1.50, desilication temperature of 100 ℃, desilication time of 4 h, and seed amount of 50g/L.