THE COARSENING OF PLASTER OF PARIS

摘要

A method for coarsening fine particles (eg below 300µm) plaster of Paris (calcium sulphate hemihydrate) by converting the particles into an elongated compacted form (9) and then subjecting the form to a breaking force (preferably a mechanical breaking force such as a crushing, hammering or cutting force) whereupon the form breaks into angular agglomerates. Also coarsened plaster of Paris comprising angular agglomerates of compacted fine particles of the plaster where preferably the agglomerates have a particle size of from 0.5 to 5mm. The compaction of the powder enables it to pour easily and with minimal dust whilst remaining capable of a quick manual dispersion in water.