The production of precipitated calcium carbonate from industrial gypsum wastes

Abstract

Precipitated calcium carbonate is a material of great interest due to its large range of applications. Although there are extensive reserves of limestone worldwide, very few deposits are of sufficient quality to provide raw materials for specialised industrial applications and uses. However, gypsum is an industrial solid waste product generated in various industrial processes. Large stockpiles of gypsum waste exist with little or no usage and commercial applications. The potential for the production of high-purity calcium carbonate from industrial waste gypsum was demonstrated in this study. The effect of various process conditions and experimental techniques were applied in order to control the morphology, structure and characteristics of the carbonate product. The use of gypsum wastes as primary material in replacement to mined limestone for the production of precipitated calcium carbonate could not only alleviate waste disposal problems but could also convert significant volumes of waste materials into marketable commodities.