Utilization of fluoranhydrite in production of binding matrices for light-weight concretes

Abstract

The production of fluorite acid out of fluorite by means of its processing by sulphuric acid is accompanied by considerable quantities of waste that is generated in the form of anhydrous calcium sulphate (fluoranhydrite). In the dumping places fluoranhydrite occupies large areas and pollutes the territory around the plant HALOGEN by dust-forming powder, which contains as much as 2  concentrated sulphuric acid. The utilization of fluoranhydrite as a raw material in the production of anhydrite binding materials enables to obtain low-cost materials and simultaneously to improve the ecological environment in the adjacent territory. Fluoranhydrite combined with neutralizing and modifying additives was used as a binding component in the production of light-weight concrete with swollen polystyrene granule–based aggregates. The obtained lightweight concrete has density mark of 500, enjoys good gas- and water vapour permeability, fire safety, prevents destruction of polystyrene at application and is strong enough to be used in production of articles such as heat-insulated slabs and construction units.