Improved coal combustion under variable BF conditions (IMPCO)
Final report - Study
Pulverized coal (PC) injection with high injection rates for minimisation of coke consumption is state of the art in BF operation. Increasing need for flexible production rate with changing operational conditions and limited availability of matching coal types cause constraints for high injection rates and result in higher total carbon consumption. Therefore, the overall objective is to reduce the coke consumption under these difficult new conditions by increased injection of conventional PC or new carbon products at the same time as the total rate of reducing agents is minimised. To reach the... objective the process has to be characterized by high stability despite changes in production rate and injection material properties. The replacement ratio to coke has to be high and well-defined for injected PC, new carbon products or mixtures of both. By carrying out the planned activities within the work program following are reached and therefore contribute to the overall objective: Definition of selection criteria for suitable injection materials for high combustion and conversion efficiency; Reaching high and stable replacement ratio of injected PC/new carbon products to coke by enhanced combustion efficiency and conversion of coal. The injection lance are modified for improved control of dispersion of coal plume and blast oxygen supply during combustion of volatiles and conversion of char; Optimisation of blast parameter settings for high combustion and conversion efficiency for selected lance design and injection material type.