GB1474839A - Process for making calcium sulphate alpha-semihydrate and apparatus used therein - Google Patents
Process for making calcium sulphate alpha-semihydrate and apparatus used thereinInfo
- Publication number
- GB1474839A GB1474839A GB4965175A GB4965175A GB1474839A GB 1474839 A GB1474839 A GB 1474839A GB 4965175 A GB4965175 A GB 4965175A GB 4965175 A GB4965175 A GB 4965175A GB 1474839 A GB1474839 A GB 1474839A
- Authority
- GB
- United Kingdom
- Prior art keywords
- autoclave
- calcium sulphate
- semihydrate
- alpha
- suspension
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
Classifications
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01F—COMPOUNDS OF THE METALS BERYLLIUM, MAGNESIUM, ALUMINIUM, CALCIUM, STRONTIUM, BARIUM, RADIUM, THORIUM, OR OF THE RARE-EARTH METALS
- C01F11/00—Compounds of calcium, strontium, or barium
- C01F11/46—Sulfates
- C01F11/466—Conversion of one form of calcium sulfate to another
-
- C—CHEMISTRY; METALLURGY
- C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
- C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
- C04B11/00—Calcium sulfate cements
- C04B11/02—Methods and apparatus for dehydrating gypsum
- C04B11/028—Devices therefor characterised by the type of calcining devices used therefor or by the type of hemihydrate obtained
- C04B11/032—Devices therefor characterised by the type of calcining devices used therefor or by the type of hemihydrate obtained for the wet process, e.g. dehydrating in solution or under saturated vapour conditions, i.e. to obtain alpha-hemihydrate
Landscapes
- Chemical & Material Sciences (AREA)
- Organic Chemistry (AREA)
- Engineering & Computer Science (AREA)
- Ceramic Engineering (AREA)
- Materials Engineering (AREA)
- Structural Engineering (AREA)
- Life Sciences & Earth Sciences (AREA)
- Geology (AREA)
- Inorganic Chemistry (AREA)
- Compounds Of Alkaline-Earth Elements, Aluminum Or Rare-Earth Metals (AREA)
- Removal Of Specific Substances (AREA)
Abstract
In a process for preparing calcium sulphate alpha -semihydrate from calcium sulphate dihydrate, which arises as a waste product in chemical processes, for example in the production of phosphoric acid by digesting rock phosphate with sulphuric acid, the calcium sulphate dihydrate in an aqueous suspension is continuously pumped into an autoclave at temperatures above 110 DEG C and recrystallised therein. Calcium sulphate alpha -semihydrate suspension is continuously drawn from the autoclave and is introduced into a separation zone. Finally, the calcium sulphate alpha -semihydrate suspension has cold water passed thereinto on its way from the autoclave to the separation zone. A plant for carrying out the process may consist of a first regulating vessel (2), a rotary filter (5), a further regulating vessel (8), an autoclave (11) and a separation apparatus (16) which are connected in series in terms of flow. Between the autoclave (11) and the separation apparatus (16) a mixing section (12) is arranged, debouching into which, close to its end facing the autoclave (11), there is a cold water supply line (15). <IMAGE>
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| DE19742459739 DE2459739C3 (en) | 1974-12-18 | Process and plant for the production of calcium sulfate alpha hemihydrate |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| GB1474839A true GB1474839A (en) | 1977-05-25 |
Family
ID=5933662
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| GB4965175A Expired GB1474839A (en) | 1974-12-18 | 1975-12-03 | Process for making calcium sulphate alpha-semihydrate and apparatus used therein |
Country Status (14)
| Country | Link |
|---|---|
| AT (1) | AT340445B (en) |
| BE (1) | BE836714A (en) |
| BR (1) | BR7508349A (en) |
| CH (1) | CH618146A5 (en) |
| DK (1) | DK142026C (en) |
| FR (1) | FR2294985A1 (en) |
| GB (1) | GB1474839A (en) |
| IE (1) | IE42222B1 (en) |
| LU (1) | LU74027A1 (en) |
| NL (1) | NL172142C (en) |
| PL (1) | PL109429B1 (en) |
| RO (1) | RO67270A (en) |
| SE (1) | SE405844B (en) |
| SU (1) | SU805943A3 (en) |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP0085382A1 (en) * | 1982-02-01 | 1983-08-10 | Quante, Heinrich | Installation for the production of alpha-calcium sulfate |
| CN111517355A (en) * | 2020-05-05 | 2020-08-11 | 桂林理工大学 | Method for preparing alpha hemihydrate gypsum from phosphogypsum under autoclaved condition |
-
1975
- 1975-12-03 GB GB4965175A patent/GB1474839A/en not_active Expired
- 1975-12-12 CH CH1615975A patent/CH618146A5/en not_active IP Right Cessation
- 1975-12-12 RO RO7584191A patent/RO67270A/en unknown
- 1975-12-15 SU SU752199179A patent/SU805943A3/en active
- 1975-12-16 LU LU74027A patent/LU74027A1/xx unknown
- 1975-12-16 NL NLAANVRAGE7514656,A patent/NL172142C/en not_active IP Right Cessation
- 1975-12-17 AT AT958575A patent/AT340445B/en not_active IP Right Cessation
- 1975-12-17 PL PL1975185660A patent/PL109429B1/en unknown
- 1975-12-17 SE SE7514272A patent/SE405844B/en unknown
- 1975-12-17 IE IE2746/75A patent/IE42222B1/en unknown
- 1975-12-17 BE BE162803A patent/BE836714A/en not_active IP Right Cessation
- 1975-12-17 BR BR7508349*A patent/BR7508349A/en unknown
- 1975-12-17 DK DK574175A patent/DK142026C/en active
- 1975-12-18 FR FR7538905A patent/FR2294985A1/en active Granted
Also Published As
| Publication number | Publication date |
|---|---|
| IE42222L (en) | 1976-06-18 |
| RO67270A (en) | 1980-03-15 |
| FR2294985B1 (en) | 1981-08-07 |
| DE2459739B2 (en) | 1976-11-18 |
| DE2459739A1 (en) | 1976-07-01 |
| LU74027A1 (en) | 1976-12-31 |
| PL109429B1 (en) | 1980-05-31 |
| BR7508349A (en) | 1976-09-08 |
| CH618146A5 (en) | 1980-07-15 |
| NL172142C (en) | 1983-07-18 |
| NL172142B (en) | 1983-02-16 |
| NL7514656A (en) | 1976-06-22 |
| DK574175A (en) | 1976-06-19 |
| SE405844B (en) | 1979-01-08 |
| AT340445B (en) | 1977-12-12 |
| DK142026B (en) | 1980-08-11 |
| DK142026C (en) | 1981-01-05 |
| BE836714A (en) | 1976-06-17 |
| FR2294985A1 (en) | 1976-07-16 |
| IE42222B1 (en) | 1980-07-02 |
| SU805943A3 (en) | 1981-02-15 |
| ATA958575A (en) | 1977-04-15 |
| SE7514272L (en) | 1976-06-21 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PS | Patent sealed [section 19, patents act 1949] | ||
| PCNP | Patent ceased through non-payment of renewal fee |