Novel eco-friendly method for preparation of mesoporous alumina from the product of rapid thermal treatment of gibbsite

Novel eco-friendly method for preparation of mesoporous alumina from the product of rapid thermal treatment of gibbsite (CTA product) without reprecipitation stage is described. Compared with the nitrate-ammonia technology of reprecipitation of gibbsite to boehmite and its further calcination to gamma-Al2O3, the new method consumed less amount of HNO3 per 1 kg of Al2O3 (by 30 times), while the amount of effluents is twice lower. Effluents do not contain ammonium nitrate, since the preparation of boehmite does not include ammonia. It is shown that the method makes it possible to obtain boehmite with needle-shaped particle morphology. The particle size of boehmite and the textural characteristics of alumina are easily adjusted over a wide range by changing the temperature, aging time or peptizing agent. Thus, the pore volume of alumina may be 0.45-0.95 cm(3)/g with an average pore diameter of 81-256 angstrom and S-BET = 140-240 m(2)/g.