IL43439A - Preparation of calcined gypsum - Google Patents
Preparation of calcined gypsumInfo
- Publication number
- IL43439A IL43439A IL43439A IL4343973A IL43439A IL 43439 A IL43439 A IL 43439A IL 43439 A IL43439 A IL 43439A IL 4343973 A IL4343973 A IL 4343973A IL 43439 A IL43439 A IL 43439A
- Authority
- IL
- Israel
- Prior art keywords
- air
- phosphogypsum
- current
- treatment
- seconds
- Prior art date
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
Landscapes
- Chemical & Material Sciences (AREA)
- Organic Chemistry (AREA)
- Engineering & Computer Science (AREA)
- Ceramic Engineering (AREA)
- Life Sciences & Earth Sciences (AREA)
- Geology (AREA)
- Inorganic Chemistry (AREA)
- Materials Engineering (AREA)
- Structural Engineering (AREA)
- Compounds Of Alkaline-Earth Elements, Aluminum Or Rare-Earth Metals (AREA)
- Curing Cements, Concrete, And Artificial Stone (AREA)
- Drying Of Solid Materials (AREA)
Claims (6)
1. Process for the preparation of plaster from phosphogypsum previously purified and dried, characterised in that: in a first stage the phosphogypsum is dehydrated by means of a current, of air in order to obtain a dehydrated phosphogypsum mixture containing at least 25% by weight of anhydrite III and the remainder hemihydrate and anhydrite II; in a second stage the said mixture is contacted with a current of moist air in order to convert the total quantity of the anhydrite III contained in the said mixture to calcium sulphate β hemihydrat
2. Process according to Claim 1, characterised .in that the first phase of the treatment is. effected by contacting, for a period of from 0.8 to 3, seconds, the pure dry phosphogypsum with a current of air whose temperature at the inlet to the treatment apparatus employe is from 260 to 330°C and whose moisture content is then from 20 to 500 grams of water per kilogram of dry air.
3. Process according to Claim Ϊ, characterised in that the firs phase of the treatment is effected by contacting, for a period of from 0.8 to 3 seconds, the pure dry phosphogypsum with a current of dry air "whose temperature at the inlet to the treatment apparatus used ivs in the range of from 350 to 450°C.
4. Process according to Claim 1, characterised in that the first phase of the treatment is e fected by contacting, for a period of from 0.8 to 3 seconds, pure dry phosphogypsum and a current of air apparatus employed 'is in the range of from 600 · o 800°C and whose moisture content is from 200 to" 500 grams of water per kilogram of dry air.
5. Process, according to any one of Claims 2 , 3 and 4, characterised in that the product obtained in the first stage is contacted for a period of from 0.8 to 3 seconds, with a current of air whose temperatur at the inlet to the treatment apparatus employed is in t range of from 20 to 50°C and whose relative humidity is in.>.the range of from 60 to 95%. .
6. Process according to Claim 1 characterised in that the two phases of the said process are carried out in a tubular pneumatic dryer constituted by a column in which circulate in the same direction, the solid particles being treated and the treatment air
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| FR7236170A FR2202851B1 (en) | 1972-10-12 | 1972-10-12 |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| IL43439A0 IL43439A0 (en) | 1974-03-14 |
| IL43439A true IL43439A (en) | 1976-08-31 |
Family
ID=9105549
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| IL43439A IL43439A (en) | 1972-10-12 | 1973-10-17 | Preparation of calcined gypsum |
Country Status (13)
| Country | Link |
|---|---|
| JP (1) | JPS4975496A (en) |
| BE (1) | BE805808A (en) |
| BR (1) | BR7307953D0 (en) |
| DE (1) | DE2350772A1 (en) |
| ES (1) | ES419558A1 (en) |
| FR (1) | FR2202851B1 (en) |
| GB (1) | GB1429259A (en) |
| IE (1) | IE38376B1 (en) |
| IL (1) | IL43439A (en) |
| IT (1) | IT999642B (en) |
| LU (1) | LU68591A1 (en) |
| NL (1) | NL7314064A (en) |
| OA (1) | OA04674A (en) |
Families Citing this family (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB2140702A (en) * | 1980-11-10 | 1984-12-05 | Bpb Industries Plc | Fluidised bed calcination |
| WO1999003795A1 (en) * | 1997-07-15 | 1999-01-28 | Karageorgis, Ioannis | Method and apparatus for the processing of phosphate gypsum waste |
| FR3059574A1 (en) * | 2016-12-07 | 2018-06-08 | Ocp Sa | PHOSPHOGYPSE EVACUATION SYSTEM |
| CN112811837B (en) * | 2020-12-31 | 2023-06-16 | 湖北聚海环境科技有限公司 | System equipment and method for dehydrating and drying phosphogypsum by using high-temperature waste heat of regenerated aggregate |
| CN113772979A (en) * | 2021-09-15 | 2021-12-10 | 贵州中建建筑科研设计院有限公司 | Reference phosphorus building gypsum and manufacturing method and application thereof |
-
1972
- 1972-10-12 FR FR7236170A patent/FR2202851B1/fr not_active Expired
-
1973
- 1973-10-09 OA OA55030A patent/OA04674A/en unknown
- 1973-10-09 BE BE2053133A patent/BE805808A/en not_active IP Right Cessation
- 1973-10-10 LU LU68591A patent/LU68591A1/xx unknown
- 1973-10-10 GB GB4741873A patent/GB1429259A/en not_active Expired
- 1973-10-10 DE DE19732350772 patent/DE2350772A1/en active Pending
- 1973-10-11 ES ES419558A patent/ES419558A1/en not_active Expired
- 1973-10-11 BR BR7953/73A patent/BR7307953D0/en unknown
- 1973-10-11 IT IT70002/73A patent/IT999642B/en active
- 1973-10-12 IE IE1825/73A patent/IE38376B1/en unknown
- 1973-10-12 JP JP48115256A patent/JPS4975496A/ja active Pending
- 1973-10-12 NL NL7314064A patent/NL7314064A/xx not_active Application Discontinuation
- 1973-10-17 IL IL43439A patent/IL43439A/en unknown
Also Published As
| Publication number | Publication date |
|---|---|
| FR2202851B1 (en) | 1978-12-29 |
| GB1429259A (en) | 1976-03-24 |
| IT999642B (en) | 1976-03-10 |
| LU68591A1 (en) | 1973-12-14 |
| JPS4975496A (en) | 1974-07-22 |
| ES419558A1 (en) | 1976-07-16 |
| BE805808A (en) | 1974-02-01 |
| NL7314064A (en) | 1974-04-16 |
| IL43439A0 (en) | 1974-03-14 |
| OA04674A (en) | 1980-07-31 |
| DE2350772A1 (en) | 1974-04-18 |
| FR2202851A1 (en) | 1974-05-10 |
| IE38376B1 (en) | 1978-03-01 |
| BR7307953D0 (en) | 1974-07-25 |
| IE38376L (en) | 1974-04-12 |
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