S. Kocakusak et al., PRODUCTION OF ANHYDROUS, CRYSTALLINE BORON-OXIDE IN FLUIDIZED-BED REACTOR, Chemical engineering and processing, 35(4), 1996, pp. 311-317
Industrial production of boron oxide is via fusion of boric acid at 55
0-1000 degrees C. The glassy melt thus obtained is then cooled until s
olid; crushed, ground and then sieved to allow classification accordin
g to particle size and distribution. The melting of boric acid is both
the most critical and costly stage of all these operations, because b
oron oxide is highly corrosive to refractories and steel. Our study al
lows the production of commercial quality anhydrous and crystalline bo
ron oxide without the melting and other processes mentioned above. Thi
s is achieved by dehydrating boric acid in a fluidized bed with a grad
ual increase in the bed temperature up to 250 degrees C. During this p
rocess as the bed temperature is increased gradually, particular atten
tion is paid to keep the dehydration rate below a certain value to pre
vent melting or sticking, and to secure the desired bulk density value
of the product.