GB1063839A - Improvements in or relating to the production of calcium sulphate -a-hemihydrate - Google Patents

Improvements in or relating to the production of calcium sulphate -a-hemihydrate

Info

Publication number
GB1063839A
GB1063839A GB4356064A GB4356064A GB1063839A GB 1063839 A GB1063839 A GB 1063839A GB 4356064 A GB4356064 A GB 4356064A GB 4356064 A GB4356064 A GB 4356064A GB 1063839 A GB1063839 A GB 1063839A
Authority
GB
United Kingdom
Prior art keywords
hemihydrate
relating
production
crystals
calcium sulphate
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
Application number
GB4356064A
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
BK Giulini Chemie GmbH
Original Assignee
Giulini Gebrueder GmbH
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Giulini Gebrueder GmbH filed Critical Giulini Gebrueder GmbH
Publication of GB1063839A publication Critical patent/GB1063839A/en
Expired legal-status Critical Current

Links

Classifications

    • 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
    • C04B11/26—Calcium sulfate cements strating from chemical gypsum; starting from phosphogypsum or from waste, e.g. purification products of smoke
    • 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
    • C04B11/024—Ingredients added before, or during, the calcining process, e.g. calcination modifiers

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)

Abstract

CaSO4. 1/2 H2O crystals are prepared by heating to 105-140 DEG C. in the presence of a crystallization promoter, an aqueous suspension of pH from 1-6 of CaSO4.2H2O which has been purified by hydro-separation to remove organic and inorganic impurities (e.g. F, P2O5, Na2O) and fine crystals, for example by elutriating with an upward current of water, or by means of hydrocyclone or continuous decanting centrifuge, repeatedly if necessary. The CaSO4.2H2O may be obtained in the recovery of H3PO4 from Ca phosphate and H2SO4. The crystallisation promoter may be an alkylanyl sulphonate, a sulphite liquor, aluminium sulphate, or a salt of a dicarboxylic acid. The pH of the suspension may be adjusted by adding CaO or Ca(OH)2. The process may be operated batchwise, under pressure, or at atmospheric pressure in the presence of a dissolved salt, e.g. 29% CaCl2 and 1% KCl.
GB4356064A 1963-10-25 1964-10-26 Improvements in or relating to the production of calcium sulphate -a-hemihydrate Expired GB1063839A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
DEG0039026 1963-10-25

Publications (1)

Publication Number Publication Date
GB1063839A true GB1063839A (en) 1967-03-30

Family

ID=7126047

Family Applications (1)

Application Number Title Priority Date Filing Date
GB4356064A Expired GB1063839A (en) 1963-10-25 1964-10-26 Improvements in or relating to the production of calcium sulphate -a-hemihydrate

Country Status (6)

Country Link
BE (1) BE654067A (en)
DE (1) DE1471177A1 (en)
FR (1) FR1411586A (en)
GB (1) GB1063839A (en)
NL (1) NL6412269A (en)
SE (1) SE338534B (en)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN105985036A (en) * 2015-02-13 2016-10-05 郑州三迪建筑科技有限公司 Processing method for phosphogypsum
US10040696B2 (en) * 2016-07-12 2018-08-07 Shandong Borui New Material Technology Co., Ltd Method for preparing α-calcium sulfate hemihydrate with calcium sulfate dihydrate

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN105985036A (en) * 2015-02-13 2016-10-05 郑州三迪建筑科技有限公司 Processing method for phosphogypsum
CN105985036B (en) * 2015-02-13 2017-11-14 郑州三迪建筑科技有限公司 A kind of processing method of ardealite
US10040696B2 (en) * 2016-07-12 2018-08-07 Shandong Borui New Material Technology Co., Ltd Method for preparing α-calcium sulfate hemihydrate with calcium sulfate dihydrate

Also Published As

Publication number Publication date
NL6412269A (en) 1965-08-25
BE654067A (en) 1965-02-01
FR1411586A (en) 1965-09-17
SE338534B (en) 1971-09-06
DE1471177A1 (en) 1968-12-05

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