Calcium Sulfate Dihydrate → Calcium Sulfate, Hemihydrate

HRID 846026

Reaction equation

HRID 846026 reaction equation
O.O.[S:3]([O-:7])([O-:6])(=[O:5])=[O:4].[Ca+2:8]>O>[OH2:4].[S:3]([O-:7])([O-:6])(=[O:5])=[O:4].[Ca+2:8].[Ca+2:8].[S:3]([O-:7])([O-:6])(=[O:5])=[O:4]

Participants

3

Reactant 1

HCID 24928Calcium Sulfate Dihydrate

Product 1

HCID 3033839Calcium Sulfate, Hemihydrate

Reagents, catalysts & solvents 1

HCID 962WaterSolvent

Procedure

When calcium sulfate dihydrate is heated sufficiently, a process called calcining, the water of hydration is driven off and there can be formed either calcium sulfate hemihydrate (CaSC4 ·1/2H2O ) or calcium sulfate anhydrite (CaSO4), depending on the temperature and duration of exposure. The term "calcined gypsum," as used herein, refers to both the hemihydrate and anhydrite forms of calcium sulfate.

Sources & evidence

ORD record
ord-b90df6d8b09d42bb9ef821eb6c6c6c96
Source dataset
uspto-grants-1992_08
Patent number
US05135805

Linked notes

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