Influence of post-combustion heat transfer efficiency on fuel reduction inCOREX process

The influence of post-combustion, heat transfer efficiency, and the degree of metallisation is studied with regard to coal saving and export gas in th e COREX process using a thermochemical model. An increase in post-combustio n ratio decreases the coal rate and the amount of reduction gas, which infl uences the achievable degree of metallisation, when no additional reduction gas is added to the system. Further post-combustion with oxygen generates a higher temperature than that with air at all post-combustion ratios. A hi gher heat transfer rate is necessary to keep the temperature of the gas wit hin the refractoriness limits of the lining material. It is asserted that t he post-combustion ratio, the degree of metallisation, and the medium for p ost-combustion must be adjusted according to the refractoriness of the lini ng material of the melter-gasifier, the efficiency of heat transfer mechani sms from the post-combustion zone to the bath, the gas handling efficiency, and the thermal energy requirement of the surplus gas, when considering th e use of post-combustion in the COREX process.