Dorr-oliver Incorporated

Southwire Company, LLC

National Steel Corporation

Earth Sciences Limited

Peter A Angevine

Stanley A Bunk

David W Leyshon

Philip M Rooke

Elliott J Roberts

Sune Bengtsson

Harry B Scott

George P Koudijs

A method for treating the fine-grained spend absorbent (primarily calcium sulfite and calcium sulfate) from a dry flue gas desulfurization process. The absorbent, having a small amount of binder therein, is oxidized in a fluidized bed reactor at a temperature in the range from about 700.degree. C. to about 1000.degree. C. to produce a dry essentially fully oxidized pelletized calcium sulfate product. Calcium sulfate pellets having an average diameter of from about 0.5 mm to 5 mm and containing from about 1% to about 3%, by weight, of binder constituents, are composed of agglomerated calcium sulfate particles having an average diameter of from about 50.mu. to about 100.mu. bound to each other by the binder constituents.

Method for oxidation of flue gas desulfurization absorbent and the

Alumina-cryolite waste from aluminum pot lines is subjected to oxidation in a fluidized bed reactor to remove carbon and organic contamination. Agglomeration of the alumina-cryolite product occurs in the fluidized bed and a pellet product suitable for return to the aluminum pot lines is produced.

Process for recovery of alumina-cryolite waste in aluminum production

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.

Fluid bed calcination process

A method for dehydrating alunite ore prior to further processing to recover metals therefrom, comprising exposing the ore in particulate form to burning coal as the heat supply in a fluidized bed fluidized with an oxygen containing gas. The invention is illustrated by the removal of water from alunite ore prior to further processing the ore to recover aluminum.

Method for dehydrating ores

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Ridgefield, CT, United States of America

Peter A Angevine