EFFECT OF ALUMINA PHASE STRUCTURE ON ITS DISSOLUTION IN CRYOLITIC MELT
Liu, X., George, S.F. and Wills, V.A.
The dissolution of alumina in cryolitic electrolyte can take place at widely varying rates dependent mainly on feeding techniques, electrolyte conditions and the characteristics of the alumina itself. The dissolution process was studied by obtaining quenched samples of the electrolyte at different stages after the addition of alumina. Results indicate that undercalcined alumina dissolves faster than alpha alumina due to the shattering of individual particles into fragments in the electrolyte. This shattering increases the surface area available for dissolution reaction. Study of phase structure and distribution of smelting grade alumina has revealed that the distribution of alpha phase in individual particles can be quite different. Distribution of alpha phase among transition phases is preferred to pure alpha particles.