PRODUCTION OF ANHYDROUS BORAX USING MICROWAVE-HEATING

Dehydration studies of borax penta- and decahydrate minerals were carried out using a microwave (MW) heating system. A 650 W microwave oven (2450 MHz) as well as a 1600 W convective heating unit was used. It was possible to produce 97.5% Na2B4O7 anhydrous borax products. Preheating affected both the quality and dehydration time of the end products. The dehydration was found to be very fast up to 2 mol of water after which its speed dropped progressively. Overall microwave heating produced cleaner products and was much faster than the conventional heating system.