AN INVESTIGATION ON THE PROCESSES FOR THE PURIFICATION OF ALUMINA BY USING THE WASH-GRINDING METHOD

As part of research to establish the industrial processes for the prod uction of high-purity alumina, these following purification processes were carried out. First, the sodium components included in the alumini um hydroxide which was used as a raw material was eliminated by adsorp tion using a silica powder, and then the exposed sodium components on the surface of alumina during the wet grinding procedure by a ball mil l was also gushed out and at the same time the particle size distribut ions of products could be controlled up to under the submicron range. The whole purification process is called the wash-grinding method. As a result, the properties of laboratory products had good agreement wit h those of commercial products and it was confirmed that the purificat ion process was technically feasible.