GB1005100A - Coke-making process - Google Patents

Abstract

In a process for producing coke from a mixture comprising a coal with good coking properties and at least one of the substances, coke breeze, ore or other mineral and coal with poor or no coking properties, the mixture is preheated before being coked in an oven by direct contact with a hot gas, the hot gas first coming into contact with a part of the mixture composed wholly or mainly of substance which is non-coking or has poor coking properties and then into contact with the rest of the mixture. The hot gas may be a mixture of fresh combustion gas at e.g. 1400 DEG C. and recirculated gas in amounts depending on the proportion of non-coking or poorly-coking substance in the mixture. In the event of this proportion being 40% by weight no gas need be recirculated. The first part of the mixture to be coked may be fed into a stream of the hot gas and the second part of the mixture added thereto or the preheated first part may be separated from the preheating gas before the second part of the mixture is introduced. In a modification a stream of preheating gas containing the first part of the mixture to be coked is led into a chamber and maintained therein as a fluidized bed, the second part of the mixture being separately introduced into the fluidized bed. The coking may be effected at between 400 DEG and 1,000 DEG C. and in an example the mixture to be coked was preheated to a temperature of 320 DEG C.