Claims
- 1. A process for reacting a soda liquor with a burned lime for production of caustic soda, comprising:
(a) forming a slurry of the burned lime and a first part of the soda liquor and allowing the slurry a retention time of 10-150 seconds in a feed vessel; (b) preheating a second part of the soda liquor; (c) combining the slurry from step (a) and the preheated second part of the soda liquor of step (b); and (d) maintaining the combined slurry and the soda liquor at an elevated pressure and at an elevated temperature for completion of the reaction between the burned lime and the soda liquor to yield a caustic soda and a lime mud.
- 2. The process according to claim 1 wherein the method further comprises filling the feed vessel with a sufficient amount of the combined slurry and the soda liquor to provide a hydrostatic pressure that is sufficiently high to prevent boiling due to an exothermic reaction between the burned lime and the soda liquor.
- 3. The process according to claim 1 wherein step (d) is performed at a pressure of at least 1.1 bar and at a temperature of 100-160° C.
- 4. The process according to claim 1 wherein step (d) is performed at a pressure of at least 1.5 bar and at a temperature of 100-160° C.
- 5. The process according to claim 1 wherein step is performed at a pressure of at least 2 bar and at a temperature of 100-160° C.
- 6. The process according to claim 3 wherein the temperature is between 110-150° C.
- 7. The process according to claim 3 wherein the temperature is between 120-140° C.
- 8. The process according to claim 1 wherein the method further comprises using a retention time in step (d) that is 1-60 minutes.
- 9. The process according to claim 1 wherein the method further comprises using a retention time in step (d) that is 10-40 minutes.
- 10. The process according to claim 1 wherein the method further comprises using a retention time in step (a) that is 20-120 seconds.
- 11. The process according to claim 1 wherein the method further comprises using a retention time in step (a) that is 30-60 seconds.
- 12. The process according to claim 1 wherein the first part of the soda liquor constitutes about {fraction (1/3)} to {fraction (1/2)} of an entire amount of the soda liquor and wherein the second part of the soda liquor constitutes about {fraction (1/2)} to {fraction (2/3)} of the entire amount of soda liquor.
- 13. The process according to claim 1 wherein the second part of the soda liquor is preheated to about 5-10° C. below the elevated temperature of step (d),
- 14. The process according to claim 13 wherein the method further comprises preheating the second part of the soda liquor by indirect heat exchanging against a caustic soda that is produced in the process.
- 15. The process according to claim 1 wherein the method further comprises allowing coarse, unreacted, burned lime to settle and thereafter discharging the burned lime.
- 16. The process according to claim 1 wherein the method further comprises filtering the lime mud and a caustic soda under elevated pressure and elevated temperature to separate the caustic soda from the lime mud.
- 17. A feeding system for feeding burned lime to a reaction vessel for causticizing a soda liquor to caustic soda, comprising:
a feeding device having an inlet defined therein for receiving a slurry of a burned lime and a first part of the soda liquor for enabling a formation of the slurry inside the feeding device; a pump in fluid communication with the feeding device and arranged to pump the slurry from the feeding device to the reaction vessel; a heater arranged to heat a second part of the soda liquor; a distributing device in fluid communication with the feeding device and arranged to distribute the first part of the soda liquor to the feeding device and to distribute the second part of the soda liquor to the heater; and a combining device in fluid communication with the pump and the reaction vessel and arranged to combine the slurry with the heated second part of the soda liquor.
PRIOR APPLICATIONS
[0001] This application is a continuation application of U.S. Ser. No. 10/031,277; filed Nov. 7, 2001; which is a US national phase patent application of PCT/SE99/00773; filed May 7, 1999.
Continuations (1)
|
Number |
Date |
Country |
Parent |
10031277 |
Dec 2002 |
US |
Child |
10430776 |
May 2003 |
US |