The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Nov. 03, 1992
Filed:
Apr. 05, 1991
Joseph W Cochran, Clearwater, FL (US);
Progress Materials Inc., St. Petersburg, FL (US);
Abstract
This invention relates to an apparatus, method and product wherein fine particles of fly ash containing carbon are oxidized in a dry, bubbling fluid bed of previously introduced fine particles of the same fly ash so that the subsequently removed particles have reduced carbon content and are useful as pozzolan, suitable for use, without further processing, to replace a portion of the cement in concrete. The preferred conditions are a temperature of about 1300.degree. to 1800.degree. F., air velocity of between at least about 0.5, but not more than about 3 ft./sec., residence time of at least about 2 minutes but up to 100 minutes, volume ratio of air to fly ash of between about 1,000 and 1500, and an excess of oxygen between about 5% and 15%.