Carbon attrition in the fluidized combustion of a metallurgical coke

The multiplication of carbon particles inside the bed of a fluidised coal combustor can be related to fragmentation and attrition. Attrition generates finer carbon which is rapidly elutriated from the bed. Previous work on attrition was carried out on a non-swelling coal. The present paper reports an extension of this work to a metallurgical coke during fluidised bed combustion. In comparison with the coal, metallurgical coal is not subject to fragmentation and is less reactive. This enabled attrition to be examined separately and at higher bed carbon content for a given fluidising velocity and excess air.