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:
Apr. 12, 1977
Filed:
Oct. 29, 1974
Peter A Angevine, Ridgefield, CT (US);
David W Leyshon, Westport, CT (US);
Dorr-Oliver Incorporated, Stamford, CT (US);
Abstract
Phosphate rock is calcined under conditions calculated to completely oxidize the carbon and sulfur in the rock. Calcination is also conducted at elevated temperature to eliminate cadmium metal, a poisonous substance in fertilizers, from the calcined rock product. A fluid bed system for eliminating cadmium metal in the calcination of phosphate rock involves a two-vessel system in which an independent cadmium removal vessel served by a separate fluidizing air stream carries out volatilization of cadmium, while preheating, precalcining and cooling is conducted in another multi-bed reactor which is served by a separate fluidizing air stream.