GB1506064A - Removal of impurities from gypsum used in the production of plaster - Google Patents

Removal of impurities from gypsum used in the production of plaster

Info

Publication number
GB1506064A
GB1506064A GB1637176A GB1637176A GB1506064A GB 1506064 A GB1506064 A GB 1506064A GB 1637176 A GB1637176 A GB 1637176A GB 1637176 A GB1637176 A GB 1637176A GB 1506064 A GB1506064 A GB 1506064A
Authority
GB
United Kingdom
Prior art keywords
gypsum
plaster
impurities
equivalents
reaction
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
GB1637176A
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.)
Rhone Poulenc Industries SA
Original Assignee
Rhone Poulenc Industries SA
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
Priority claimed from FR7513923A external-priority patent/FR2270598B1/fr
Application filed by Rhone Poulenc Industries SA filed Critical Rhone Poulenc Industries SA
Publication of GB1506064A publication Critical patent/GB1506064A/en
Expired legal-status Critical Current

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
    • C01F11/468—Purification of calcium sulfates
    • 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

Abstract

1506064 Gypsum purification RHONE-POULENC INDUSTRIES 22 April 1976 [25 April 1975] 16371/76 Heading C1A Impurities are removed from by-product gypsum by reaction of an aqueous slurry of gypsum with an alkaline compound added in an amount given by the equation Q = Q o + K p , where Q is the number of OH equivalents added per kg of the gypsum, Q o is the number of OH equivalents required to neutralize the soluble acid materials in the water,p is the percentage fluorine content of the system, and K is a coefficient from 0À2 to 0À6 and represents the number of OH equivalents required to convert the complex fluorine compounds in 1 kg of the gypsum to simple fluoride salts of alkali metals or alkaline earth metals; the mixture thus formed is agitated to form an homogeneous reaction medium which is maintained until the reaction is complete when at least a part of this suspension is drawn off and filtered, the product obtained is then dried and heat treated to form a plaster. Suitable alkaline compounds include lime, CaCO 3 , NaOH, Na 2 CO 3 , KOH, K 2 CO 3 , MgO and MgCO 3 .
GB1637176A 1975-05-05 1976-04-22 Removal of impurities from gypsum used in the production of plaster Expired GB1506064A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
FR7513923A FR2270598B1 (en) 1974-05-06 1975-05-05

Publications (1)

Publication Number Publication Date
GB1506064A true GB1506064A (en) 1978-04-05

Family

ID=9154820

Family Applications (1)

Application Number Title Priority Date Filing Date
GB1637176A Expired GB1506064A (en) 1975-05-05 1976-04-22 Removal of impurities from gypsum used in the production of plaster

Country Status (1)

Country Link
GB (1) GB1506064A (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4319927A (en) 1980-05-07 1982-03-16 The Flintkote Company Portland-type cements

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4319927A (en) 1980-05-07 1982-03-16 The Flintkote Company Portland-type cements

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Legal Events

Date Code Title Description
PS Patent sealed
PCNP Patent ceased through non-payment of renewal fee