Anhydrous gypsum

Synonyms anhydrous calcium sulfate-anhydrite muriacite karstenite anhydrous gypsum anhydrous sulfate of lime hemihydrate-plaster of Paris annalin dried gypsum dried calcium sulfate dihydrate-gypsum alabaster satin spar mineral white terra alha satinite light spar selenite precipitated calcium sulfate native calcium sulfate... 

Calcium sulfate anhydrous anhydrite anhydrous gypsum anhydrous sulfate of lime Destab-, Drierite-, E516 karste-nite muriacite Snow White. 

After evaporation, the highly concentrated salt solution containing solid salts remains in evaporator. The residue is transferred and solidified with anhydrous gypsum. The solid has 1/5 -1/10 volume of the original solution. 

Also known as anhydrous sulfate of lime, anhydrous gypsum is having somewhat pinkish colour. 

OTHER names Anhydrous gypsum also see Overview for synonyms of hyd rates... 

SYNONYMS anhydrite, anhydrous calcium sulfate, anhydrous gypsum, anhydrous sulfate of lime, calcium salt of sulfuric acid. 

Synonyms/Trade Names Anhydrous calcium sulfate, Anhydrous gypsum, Anhydrous sulfate of lime. Calcium salt of sulfuric acid [Note Gypsum is the dihydrate form Plaster of Paris is the hemihydrate form.]... 

Anhydrous calcium sulfate Anhydrous gypsum. See Calcium sulfate Anhydrous iron oxide. See Ferric oxide Anhydrous lanolin. See Lanolin... 

Synonyms Anhydrite (natural form) Anhydrous calcium sulfate Anhydrous gypsum Calcium sulfate (1 1) Calcium sulfonate Gypsum Plaster of Paris Sulfuric acid, calcium salt Sulfuric acid, calcium salt (1 1) Classification Inorganic salt Empirical CaOjS Formula Ca H2O4S... 

Anhydrous gypsum plaster contains -anhydrite (A-III ) as its main constituent. It is produced in a similar way to hemihydrate gypsum plaster, but at higher calcination temperatures. The binder is very hygroscopic, and tends to absorb water vapor rapidly from the air to convert to hemihydrate. The hemihydrate formed in this way hydrates rapidly to dihydrate, if mixed with water. The properties of this binder are similar to those of hemihydrate gypsum plaster. 

The hydrous form of calcium sulfate, Terra Alba, contains about 20% water of crystallization. It is processed by fine grinding and air-separation to a selected, white, high purity gypsum. The anhydrous gypsum form is obtained by the same process, the addition of a calcination step in which water is almost entirely removed (only about 0.3% remains). Particles are mostly smaller than 10 pm. Oil absorption is rather high, in the range of 23 to 26 g/100 g. The choice between the hydrous and the anhydrous forms depends on the processing temperature and the moisture sensitivity of the formulation. 

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