The Influence of Mechanical Activation on the Dissolution Rate of Australian Alumina
摘要
For the first time, the results of studies of the physical and mechanical properties of certified alumina from the Australian company, Queensland Aluminum Ltd., after gas purification, mechanical activation (MA) and dissolution rate in an electrolyte with a cryolite ratio (CR) of 2.3, the addition of 5% CaF2 and a temperature of 960°C ± 10°C are presented. The rate of alumina dissolution before and after MA was determined using the potentiometric method at different contents of alumina in the electrolyte. It has been shown that the dissolution rate of Al2O3 containing 1–5 wt.% before MA does not depend on the concentration of alumina and is 0.6 mol/m3 s (63.6 g/m3 s), while the dissolution rate of alumina after MA increases from 2.2 mol/m3 s to 3.7 mol/m3 s (233.2–392.2 g/m3 s) with increasing Al2O3 concentration from 1 wt.% to 2 wt.%. It is recommended to carry out MA in an M-3 planetary mill with duration of 5 s, a ball diameter of 3 mm, and a mass ratio of the sample and grinding media of 10:1.