Patent EA-000171-B1 (EA)
Title: Production of substance containing boric oxide and method therefor
Inventor: FISHER RICHARD P
IPC: C01B35/10
Filed: 1996-04-29
Abstract: 1 A method for producing an amorphous boric oxide-containing product having from about 80 to 90% by weight B2 O3 which comprises heating boric acid to a temperature in the range of from about 180 to 220 degree C for a period of time sufficient to dehydrate said boric acid and form a molten glass containing about 80 to 90% by weight B2 O3, and cooling said molten glass to form a solid glassy product. 2. The method according to Claim 1 in which said glassy product is comminuted to form a particulate boric oxide product containing about 80 to 90% by weight B2 O3. 3. The method according to Claim 1 in which said boric acid is dehydrated in a heated reactor-mixer. 4. The method according to Claim 3 in which said heating is applied by means of a heated fluid circulated through a jacket surrounding said reactor-mixer. 5. The method according to Claim 3 in which said reactor-mixer is a horizontal single-shaft mixer. 6. The method according to Claim 3 in which said reactor-mixer is a horizontal twin-shaft mixer. 7. The method according to Claim 6 in which said reactor-mixer is a Kneadermaster mixer. 8. The method according to Claim 1 in which said boric acid is heated to a temperature of about 195 degree  to 205 degree C. 9. The method according to Claim 1 in which said boric oxide product contains about 84 to 86% by weight B2 O3. 10. A boric oxide product comprising about 80 to 90% by weight B2 O3, produced by dehydration of boric acid according to the method of Claim 1. 11. A boric oxide product according to Claim 10 having about 84 to 86% by weight B2 O3. 12. A continuous process for producing an amorphous boric oxide product containing about 80 to 90% by weight B2 O3, which comprises feeding boric acid continuously into a reactor-mixer, mixing and heating said boric acid in said reactor-mixer to a temperature in the range of about 180 degree  to 220 degree C for a period of time sufficient to dehydrate said boric acid and form a fluid molten glass containing about 80 to 90% by weight B2 O3, discharging said fluid molten glass from said reactor-mixer through a heated exit means, cooling said molten glass to form a solid glassy product, and comminuting said glassy product to form a particulate amorphous boric oxide product containing about 80 to 90% by weight B2 O3. 13. The process according to Claim 12 in which said discharged molten glass is fed to rotating chill rolls to cool and solidify said molten glass. 14. The process according to Claim 12 in which said boric acid is heated by means of a heated fluid circulated through a jacket surrounding said reactor-mixer. 15. The process according to Claim 12 in which said boric acid is heated to a temperature in the range of about 195 degree  to 205 degree C. 16. The method according to Claim 12 in which said reactor-mixer is a horizontal single-shaft mixer. 17. The method according to Claim 12 in which said reactor-mixer is a horizontal twin-shaft mixer. 18. A boric oxide product comprising about 80 to 90% by weight B2 O3, produced by dehydration of boric acid according to the method of Claim 12. 19. The process according to Claim 12 in which said boric oxide product contains about 84 to 86% by weight B2 O3.