Claims
- 1. In a process utilizing steam, a method of producing and supplying at least a portion of said steam, comprising the steps of
- (a) heating a solid substance in a decomposer at a pressure greater than one atmosphere gage pressure
- i. for decomposing said substance to drive off chemically combined water, and
- ii. for yielding said water in the form of steam which is at least 50% by volume H.sub.2 O at a pressure greater than one atmosphere gage pressure,
- (b) removing said steam from the decomposer while keeping said steam at a pressure greater than one atmosphere gage pressure,
- (c) capturing said steam, still at a pressure greater than one atmosphere gage pressure, for said process, said process being external to said decomposer, and
- (d) feeding said steam, still at a pressure greater than one atmosphere gage pressure, to said process.
- 2. A method as claimed in claim 1, wherein the solid substance yields a steam which is essentially 100% H.sub.2 O.
- 3. A method as claimed in claim 1, wherein the solid substance yields a steam which is at least 94% by volume H.sub.2 O.
- 4. A method as claimed in claim 1, wherein the solid substance yields a steam which is at least 75% by volume H.sub.2 O.
- 5. A method as claimed in claim 1, wherein the solid substance is aluminum fluoride.
- 6. A method as claimed in claim 1, wherein the steam is essentially free of CO.sub.2.
- 7. A method as claimed in claim 1, wherein the steam is essentially free of contaminants.
- 8. A method as claimed in claim 1, wherein the steam is essentially free of organic compounds.
- 9. A method as claimed in claim 1, wherein the solid substance is aluminum hydrate.
- 10. A method as claimed in claim 9, wherein the conditions of temperature, pressure, and time in the step of heating are insufficient to convert said aluminum hydrate to alpha alumina.
- 11. A method as claimed in claim 1, further comprising piling particles of the substance on top of one another, whereby the particles form a bed, with the water being evolved in a gaseous state and self-fluidizing said bed.
- 12. A method as claimed in claim 9, wherein the aluminum hydroxide comprises a bed in the step of heating, said bed being fluidized.
- 13. A method as claimed in claim 12, wherein said water self-fluidizes the bed.
- 14. A method as claimed in claim 9, the step of heating being carried out at a temperature of up to approximately 650.degree. C.
- 15. A method as claimed in claim 1, wherein the process utilizing steam comprises treating a slurry of bauxite ore with sodium hydroxide solution to dissolve aluminum values while maintaining temperature and pressure conditions of the slurry with steam.
- 16. A method as claimed in claim 1, wherein the solid substance comprises Al(OH).sub.3 and the temperature, pressure, and time in the step of heating are insufficient to convert said Al(OH).sub.3 to alpha alumina.
- 17. A method as claimed in claim 1, wherein the step of heating comprises indirect heating with combustion gases.
- 18. A method as claimed in claim 15, wherein the solid substance comprises Al(OH).sub.3, the step of heating comprises indirect heating, and the temperature, pressure and time in the step of heating are insufficient to convert the Al(OH).sub.3 to alpha alumina.
- 19. A method as claimed in claim 1, wherein the solid substance comprises hydrated aluminum fluoride, the step of heating comprises indirect heating, and the temperature, pressure and time in the step of heating are sufficient to prevent hydrolysis of said solid substance.
- 20. A method as claimed in claim 1, wherein the conditions of temperature, pressure and time in the step of heating are sufficient to prevent hydrolysis of said solid substance.
- 21. A method as claimed in claim 1, wherein the conditions of temperature, pressure and time in the step of heating are sufficient to cause hydrolysis of said solid substance.
- 22. A method as claimed in claim 1, the step of heating being carried out at a temperature greater than approximately 150.degree. C.
- 23. A method as claimed in claim 1, the step of heating being carried out at a temperature of up to approximately 650.degree. C.
- 24. A method as claimed in claim 5, the step of heating being carried out at a temperature of from approximately 150.degree. C. to approximately 250.degree. C.
CROSS-REFERENCE TO RELATED APPLICATION
This application is a continuation-in-part application of U.S. Ser. No. 514,292, filed Apr. 24, 1990 now U.S. Pat. No. 5,141,734, which in turn is a continuation-in-part application of U.S. Ser. No. 729,542, filed May 2, 1985, abandoned which in turn is a continuation application of U.S. Ser. No. 548,948, filed Nov. 7, 1983, now U.S. Pat. No. 4,770,869.
US Referenced Citations (2)
Number |
Name |
Date |
Kind |
4770869 |
Misra et al. |
Sep 1988 |
|
5141734 |
Misra et al. |
Aug 1992 |
|
Foreign Referenced Citations (4)
Number |
Date |
Country |
7693 |
Nov 1954 |
JPX |
18797 |
Sep 1972 |
JPX |
20286 |
Feb 1980 |
JPX |
1961 |
Jan 1983 |
JPX |
Continuations (1)
|
Number |
Date |
Country |
Parent |
548948 |
Nov 1983 |
|
Continuation in Parts (2)
|
Number |
Date |
Country |
Parent |
514292 |
Apr 1990 |
|
Parent |
729542 |
May 1985 |
|