Low-temperature Carbonization of Non-Caking Coals from Raniganj

High volatile non-caking Upper Kajora and Jambad Bowlah coals (Raniganj Coalfield) have been studied for low-temperature carbonization on laboratory, bench and semi-pilot-plant scales with the temperature of carbonization varying between 500º to 715ºC. the results show that the optimum yield of tar and quality of coke are obtained at 600ºC as measured at the centre of coke mass. In an externally heated rotary retort (Fischer assay) the yield of tar is higher but the quality of the coke deteriorates due to high content of fines produced during carbonization. Correlations were found to exist between the laboratory assay (Grav King and Fischer) and semi-pilot-scale test yields. Correlations were also developed between these yields and those likely to be obtained in full-scale narrow vertical retorts. From the latter correlation, the yields of large-scale operation using these coals could be estimated