PRODUCTION OF ANHYDROUS, CRYSTALLINE BORAX IN A FLUIDIZED-BED

Industrial production of anhydrous borax is via fusion of borax deca- or pentahydrate at 800-1000 degrees C. The glassy melt obtained thus i s then cooled to solidify, crushed, ground, and then sieved to be clas sified according to its particle size and distribution. Since molten b orax is highly corrosive to refractories and steel, among all these op erations, the melting of borax is the most critical and the most costl y. Our study gives way to production of commercial quality anhydrous a nd crystalline borax by eliminating melting and other above-mentioned operations. For this purpose, borax pentahydrate is dehydrated in a fl uidized bed with gradually increasing the bed temperature up to 550 de grees C. During this process, as the bed temperature is increased grad ually, particular attention is paid to keep the dehydration rate below a certain value to secure the bulk density of the product at levels g reater than 0.3 g/cm(3).