The New Alusuisse Process for Producing Coarse Aluminum Hydrate in the Bayer Process

Summary

The liquor productivity in the American Bayer process, with a maximum of about 55 g Al₂O₃ per liter, compares very unfavorably with that obtained in the European process of up to 80 g Al₂O₃ per liter. By the new Alusuisse process a liquor productivity can be obtained nearing that of the European process, but consisting of a coarse aluminum hydroxide typical of the American process. The process has been used for the conversion from floury to sandy aluminas at the Gove Alumina Plant with a nominal capacity of 1.0 million tons per year. The modified plant has been running since November 1979 at the increased nominal capacity of 1.1 million tons per year, producing an aluminum hydrate of about 5% smaller than 45µm.