Reactive alumina production for the refractory industry

In this study, fine reactive alumina powder production was investigated using Bayer gibbsite as a starting material. Experimental studies consist of three steps; in the first step, the soda content was reduced by means of boric acid and distilled water. In the second step, the effect of heating rate and calcinations temperature on crystal size, phase transformation and surface area were investigated and characterization of the powders was performed by means of XRD and SEM analyses. In the third step, the powders obtained optimum conditions were ground in an attritor mill and then particle size distribution and surface area were measured. The soda content of the gibbsite was reduced from 0.325 to 0.05% by H3BO3 treatment, calcination at 1200 °C and then washing in distilled water. The higher the heating rate, the smaller the crystal size is. Alumina ceramics with a density higher than 94.70% of theoretical density were obtained.