HYDRAULIC BINDER BASED ON CALCIUM SULPHATE, PROCESS FOR PRODUCING THE SAME AND SPECIFIC USES THEREOF

摘要

The present invention relates to a new hydraulic binder based on calcium sulphate comprising stabilized soluble anhydrite III in a ratio ranging from 60% to 80% by weight, soluble anhydrite II in a ratio ranging from 10% to 30% by weight, low-soluble anhydrite II in a ratio ranging from 8% to 25% by weight and impurities ranging from 0% to 5% by weight. The invention also relates to a process for the preparation of a hydraulic binder comprising the following steps: the introduction of the powdery composition based on calcium sulphate into an impacting conduit containing overheated air; the heating of the composition to a temperature ranging from 320°C to 380°C, in conditions of overpressure from 50 to 100 mbar; and impacting the binder particles against the conduit walls, by passing a warm air stream with an air stream velocity ranging from 10 to 25 m/s. Another object of the present invention is the use of the hydraulic binder as an absorbent material for depolluting the hydropollutant discharges into solid or liquid environment and a process for depolluting a liquid or solid environment polluted with hydropollutants discharges wherein the hydraulic binder is sprayed in a sufficient amount onto the pollutant material surface, followed by recovering the binder and pollutant material aggregates formed by rehydration. The invention also relates to processes for road repairing wherein the hydraulic binder is used.