Production of synthetic anhydrite
AssigneeBayer Aktiengesellschaft
InventorsFriedrich Hinsche, Kurt Schaupp
Life of this patent
Estimating the term…
Abstract
The process for the production of synthetic anhydrite of uniform quality from the residue resulting from the production of hydrofluoric acid and containing calcium sulfate and acid, comprising suspending said residue in water with vigorous agitation, neutralizing said residue, grinding the suspension and separating water from the suspension to leave synthetic anhydrite containing less than about 50% water by weight. The product is thereafter dried after the optional addition of fillers and/or additives which accelerate subsequent hydration.
Claims10
In the production of synthetic anhydrite wherein calcium fluoride and sulfuric acid are reacted to form hydrofluoric acid, the hydrofluoric acid is removed leaving a residue comprising synthetic insoluble anhydrite and acid, and recovering synthetic anhydrite from the residue, the improvement which comprises separating the fines from the residue, suspending said fines-free residue in water with vigorous agitation, neutralizing said residue, grinding the suspension, separating water from the suspension to leave synthetic insoluble anhydrite containing about 10 to 50% of water by weight, mixing the residual material with the previously separated fines, and thereafter allowing said mixture to set.
Dependencies are inferred from the claim text.