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US 5,330,572 AGranted
Method of slaking quicklime contained in ash
AssigneeCharbonnages De France (Etablissement Public)
InventorsJacques Blondin, Oussama Baalbaki
Life of this patent
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Abstract
According to the method fly ash is pre-hydrated using cold water and the mixture is then treated in a receptacle under pressure from superheated or saturated steam at a temperature lying between 130.degree. C. and 250.degree. C. The method is applicable to any substance containing quicklime that is to be slaked.
Claims6
A method of slaking quicklime in fly ash to provide a hydraulically settable mixture, comprising:
- (1) wetting the ash at ambient temperature in a first stage with a quicklime slaking stoichiometric excess of cold water to form prehydrated ash such that the quicklime therein is completely wetted but without hydration of compounds in the fly ash other than quicklime and wherein the cold water is up to 20% by weight of the ash;
- and
- (2) contacting the prehydrated ash at a temperature between about 130.degree. C. and 250.degree. C. in a receptacle in a second stage with steam under pressure such that hydration of the quicklime is substantially completed, excess water is eventually vaporized and hardening of the ash is prevented.
Dependencies are inferred from the claim text.