PREPARATION OF PSEUDO-BOEHMITE BY USING HIGH-ALUMINA COAL FLY ASH

摘要

Fly ash is a very important unconventional aluminum resource in which the alumina content comes up to 40 ～ 60% in part of China. It has great economic and environmental value to exploit the recycling method of fly ash and produce high value-added multi-alumina products. In this paper, preparation of pseudo-boehmite by using Inner Mongolia Datang fly ash sintering clinker has been investigated. After a series of processing under optimized conditions (dissolution at 80°C, 60min, liquid solid ratio 4:1, first stage desilication 120min, 170°C, sodium silicon slag 100 g/l, sec-stage desilication 120 min, 90°C, CaO content 15 g/l), the silica ratio of the solution reaches up to 838, which conforms to the requirement of the industry. The pore volume of the seed precipitation product reaches 0.8291cm~3/g, which is almost the same with standard sample. The Na_2O content of pseudo-boehmite prepared is below 0.3%, which can meet the sodium content requirements of general catalyst.