Influence of thermal conductivity of ceramic materials on heating rate/coking time and coke quality in cokemaking

Abstract

The Iron and Steel Industry has undergone a radical change, and processes have been developed continually for the faster rate of production. The thermal characteristic of reaction depends on the thermal conductivity of coal charge by progressively developing the zone of coke. In general, higher the oven temperature, the more rapid is the initial rate of heating, plastic temperature range, plasticity and volatile evolution characteristics of the coal. The higher thermal conductivity of bricks will increase heat transfer rate and consequently, the output of the oven will increase the throughput. The heating rate is also associated with the pattern of heat supply during carbonization which influences the strength and fissuring of the coke. Results show that replacement of LC-65 castable with higher thermal conductivity castable SiC-30% reduces the coking time by 50% whereas LC-85 reduces the coking time by 20% even at same coke end temperature and coke CSR. The requirement of free space temperature of the laboratories oven is different for using different thermal conductivity of the ceramic castable to maintain same heating rate and coke end temperature during coking. Results confirmed that increasing the thermal conductivity of ceramic castable decrease in the free space temperature to maintaining the constant heating rate (∼4 °C/min) and coke end temperature (∼925 °C). The results also depict that the use of SiC-30 and LC-85 castable, the input temperature should be reduced by ∼200 °C and ∼100 °C to maintain the same heating rate and coke end temperature as compared to LC-65 castable. The study will also beneficial for reducing the Noxs.