Obtaining sulfate binder made of anhydrite III from material having gypsum, useful e.g. to fabricate special means such as helicopter, comprises grinding gypsum to obtain powder product, heating and cooling product and grinding product

摘要

Obtaining a sulfate binder (1) made of anhydrite III from a material mainly made of gypsum, comprises: grinding the gypsum (2) to obtain a powder product to be transformed along a granular zone of gypsum of less than 3 mm; heating the product for 1-1 hour 30 minutes to be transformed at a temperature of 250-350[deg] C in wet medium, under a saturated vapor pressure and depression of -10 Pa to -30 Pa; cooling the heated powder product present in the medium able to stop its hydration; and grinding the cooled product to obtain the binder having a size less than 200 microns. Process for obtaining a sulfate binder (1) made of anhydrite III from a material mainly made of gypsum, comprises: grinding the gypsum (2) to obtain a powder product to be transformed along a granular zone having gypsum of less than 3 mm; heating the powder product for 1-1 hour 30 minutes to be transformed at a temperature of 250-350[deg] C in wet medium, under a saturated vapor pressure and depression of -10 Pa to -30 Pa; cooling the heated powder product present in the medium able to stop its hydration; and grinding the cooled product to obtain the binder having a size less than 200 microns, where the grinding comprises preparing the powder product to be transformed by grinding independently associated with a part of the gypsum and secondly a sulfoaluminate and/or ferro-aluminous clinker (3), then heating all the gypsum and clinker in powder state by introducing simultaneously in furnace (14). Independent claims are included for: (1) an installation able to implement the process comprising: first means of grinding of gypsum; routing means (12) of the powder product to be transformed towards a rotary kiln; rotary kiln; rotary kiln provided with means for maintaining a voltage of saturating vapor and a depression of -10 to -30 Pa; means for cooling the heated product comprising a containment chamber able to prevent its hydration; second means of grinding the cooled product able to reduce into a powder product forming the binder to obtain a size less than 200 microns, where the installation comprises a mixer of homogeneous distribution between the grains of the powder product made of gypsum and grains of the powder product made of clinker, arranged downstream of the routing means; and (2) a sulfate binder obtained by the process and the installation.