NL7208446A - Calcium sulphate semihydrate - by roasting mixt of calcium sulphate anhydrite and semihydrate and/or dihydrate, and addi - Google Patents

Calcium sulphate semihydrate - by roasting mixt of calcium sulphate anhydrite and semihydrate and/or dihydrate, and addi

Info

Publication number
NL7208446A
NL7208446A NL7208446A NL7208446A NL7208446A NL 7208446 A NL7208446 A NL 7208446A NL 7208446 A NL7208446 A NL 7208446A NL 7208446 A NL7208446 A NL 7208446A NL 7208446 A NL7208446 A NL 7208446A
Authority
NL
Netherlands
Prior art keywords
calcium sulphate
mixt
semihydrate
dihydrate
roasting
Prior art date
Application number
NL7208446A
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 filed Critical
Priority to NL7208446A priority Critical patent/NL7208446A/en
Publication of NL7208446A publication Critical patent/NL7208446A/en

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

Landscapes

  • Chemical & Material Sciences (AREA)
  • Organic Chemistry (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • Geology (AREA)
  • Inorganic Chemistry (AREA)
  • Compounds Of Alkaline-Earth Elements, Aluminum Or Rare-Earth Metals (AREA)

Abstract

Calcium sulphate hemihydrate, for use in the gypsum industry, is prepd. from a mixt. of calcium sulphate-anhydrite and calcium sulphate hemihydrate and/or dihydrate by (a) roasting the mixt. at above 200 degrees C, esp. 450 degrees C, (b) cooling, and (c) adding calcium sulphate dihydrate to the mixt. when it is cooled to 200-250 degrees C in such an amount that a stoichiometric water of hydration content is produced, and practically the whole mixt. is converted into calcium sulphate hemihydrate. Large scale economical prodn. esp. from waste gypsum produced from phosphoric acid prepn.
NL7208446A 1972-06-20 1972-06-20 Calcium sulphate semihydrate - by roasting mixt of calcium sulphate anhydrite and semihydrate and/or dihydrate, and addi NL7208446A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
NL7208446A NL7208446A (en) 1972-06-20 1972-06-20 Calcium sulphate semihydrate - by roasting mixt of calcium sulphate anhydrite and semihydrate and/or dihydrate, and addi

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
NL7208446A NL7208446A (en) 1972-06-20 1972-06-20 Calcium sulphate semihydrate - by roasting mixt of calcium sulphate anhydrite and semihydrate and/or dihydrate, and addi

Publications (1)

Publication Number Publication Date
NL7208446A true NL7208446A (en) 1973-12-27

Family

ID=19816315

Family Applications (1)

Application Number Title Priority Date Filing Date
NL7208446A NL7208446A (en) 1972-06-20 1972-06-20 Calcium sulphate semihydrate - by roasting mixt of calcium sulphate anhydrite and semihydrate and/or dihydrate, and addi

Country Status (1)

Country Link
NL (1) NL7208446A (en)

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