Producing sulphur di:oxide-contg. gas and cement clinker from waste gypsum

摘要

Waste gypsum is dried and calcined until the anhydrite is formed followed by the addition of additive material. The mixt. is then treated in a rotating furnace where the anhydride is broken down and converted to a cement clinker. The reducing agent included in the additive material is paper fibres which are added in the form of old paper such that the carbon content is 3.4-6 wt.% of the anhydrite. Appts. for carrying out the process is also claimed.