Abstract: Green briquettes made from particulate carbonaceous material and lignosulfonate as a binder are cured in an oven in the presence of circulating gases containing a high percentage of oxygen and superheated steam. The sulfur derived from the binder is oxidized and then hydrolyzed (exothermic reactions) at the curing temperature with formation of sulfuric acid, which is dissociated (endothermic reaction) in the case of a temperature rise. The reactions provide a means for thermal balance within the curing oven.
Type:
Grant
Filed:
January 28, 1988
Date of Patent:
April 25, 1989
Assignee:
Petrofina, U.K. Ltd.
Inventors:
Peter R. McCrainor, Peter B. Caplin, James W. Middlemas, Geraint Rees, Mario Angelini