MAINTAINING PRODUCT QUALITY AND PRODUCTION WHILE INTRODUCING A NEWLY DEVELOPED VENEZUELAN BAUXITE DEPOSIT

Peleato, F.

CVG-INTERALUMINA, a Venezuelan alumina plant with presently a capacity of 1.3 MTY, is now involved in the expansion of its capacity to 2.0 MTY and at the same time changing its feed stock from imported bauxites with origin Gove-Australia, Trombetas-Brazil and Berbice Linden Guyana to bauxite from the Los Pijiguaos deposits in Venezuela. This bauxite being mined for the first time on commercial scale, has raised concern because of its low reactive silica.

Encountering in the digested slurry, both in plant trials and in the laboratory liquor recycling tests, levels of silica higher than that at our current operation, predesilication stage preceding Digestion has been included in the plant expansion to avoid any risk of operating problems and off-grade product. However, since we want to start using increasing quantities of local bauxite, while the desilication plant is not available within a year, we started laboratory investigation with various blends of our bauxite with other currently imported bauxites, to ensure an acceptable plant operation in the transition period.

This paper presents the results obtained, along with comments on our operating experiences and our approach to develop a suitable adaptation strategy.