Method for producing an anhydrite III or α based hydraulic bonding agent
AssigneeSociete Europeenne d′Exploitation de Technologies Industrielles
InventorJean Couturier
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Abstract
A process for synthesizing a hydraulic binder based on natural calcium sulfate (gypsum), the process consisting in heating the calcium sulfate to obtain a large proportion of anhydrite III or α anhydrite, and then in quenching. The process consists in: completely dehydrating the calcium sulfate, and suddently cooling the matter thus dehydrated. The present invention finds a preferred application in the construction industry in obtaining a hydraulic binder that can be used as cement.
Claims9
A process for synthesizing a hydraulic binder from natural calcium sulfate or synthesized calcium sulfate, consisting in treating said calcium sulfate to form:
- a hydraulic binder comprising anhydrite III or α anhydrite comprising:
- a heating the calcium sulfate from ambient temperature to a temperature in the range 220° C. to 350° C. depending on the characteristics of the calcium sulfate in the treating step;
- rapidly quenching the product obtained by reducing its temperature from 220° C.-350° C. to less than 80° C. in less than two minutes, for stabilizing the α anhydrite by crystallographic blocking and fixing;
- and
- obtaining an hydraulic binder that contains more than 70% of stable, soluble anhydrite III or α anhydrite.
Dependencies are inferred from the claim text.