EVALUATION OF THE PRECIPITATION CIRCUIT OPERATION PARAMETERS TO CONTROL THE ALUMINA ATTRITION INDEX

摘要

The alumina granulometry is of vital importance in the quality characteristics required by the client. The attrition index in the hydrate particles obtained during the Bayer process has marked influence on the results of final product granulometry. In C.V.G. Bauxilum has been possible to reduce 52 % the alumina attrition index in the last decade, reducing its value from 23 % to 11 %, by means of controlling the precipitation circuit operation parameters. These parameters are directly related with the saturation of the mother liquor, where the mother liquor temperature and caustic molar ratio stand out, combined with the quantity and size grain of the fine seed fed to the agglomeration phase.