Claims
- 1. A method of removing salt from gypsum plaster supplied to a manufacturing process for the production of set gypsum products which comprises rapidly and continuously mixing a continuous supply of dry salt-bearing gypsum plaster with a flow of water having a temperature below the hydration transition temperature of gypsum at which rapid hydration of gypsum plaster can occur and continuously separating a substantial portion of the water containing dissolved salt from the plaster, the time elapsing between mixing of the plaster with water and separating a substantial proportion of the water being less than 30 seconds thereby ensuring that unacceptable hydration does not occur, and conveying the damp or wet plaster to the manufacturing process.
- 2. A method of removing salt from gypsum plaster supplied to a manufacturing process for the production of set gypsum products which comprises rapidly and continuously mixing a continuous supply of dry salt-bearing gypsum plaster with a flow of water having a temperature of 0 .degree. to 40.degree. C., continuously separating a substantial portion of the water containing dissolved salt from the plaster by continuous separation, the time elapsing between mixing of the plaster with water and separation of a substantial proportion of the water not exceeding 30 seconds, and conveying the damp or wet plaster free from a substantial amount of salt to the manufacturing process.
- 3. The method of claim 2 wherein the water is at a temperature of 0 .degree. to 30.degree. C.
- 4. The method of claim 2 in which the weight ratio of the flow of water to the supply of plaster is from 1:1 to 5:1.
- 5. The method of claim 2 in which the water is separated from the plaster by continuous centrifugal separation.
- 6. The method of claim 1, wherein the separation is effected in a period of time up to 15 seconds.
Priority Claims (2)
Number |
Date |
Country |
Kind |
31113/76 |
Jul 1976 |
GBX |
|
43773/76 |
Oct 1976 |
GBX |
|
CROSS REFERENCE TO RELATED APPLICATION
The present application is a continuation-in-part of co-pending application Ser. No. 819,150 filed July 26th 1977 now abandoned
US Referenced Citations (1)
Number |
Name |
Date |
Kind |
2285098 |
Schoch et al. |
Jun 1942 |
|
Continuation in Parts (1)
|
Number |
Date |
Country |
Parent |
819150 |
Jul 1977 |
|