EFFECTS OF PRE-HEATING ON THE MICUM STRENGTH OF COKE FROM A COAL BLEND INCLUDING 5% OF NON-CAKING NIGERIAN OKABA COAL

A coal blend consisting of 95% Australian Agro-Allied coal and 5% Nigerian non-caking Okaba coal wascarbonized in a 250 kg capacity coke oven at a flue temperature of 1,250oC by normal wet and preheatedcharging for 18 and 15 hours, respectively. Screen distribution analysis and micum drum tests on thecoke products gave M10 of 24.60% and 9.5% and M40 of 67% and 76.2%, for normal and preheatedcharge, respectively. These results showed that the coke produced from the preheated charge has abetter resistance to abrasion (M10) and fragmentation (M40) and the micum indices obtained are similarto the micum characteristics of cokes produced in coke ovens in some other countries. Furthermore,the coke micum 10 and micum 40 strength are very close to the M10 and M40 specifications for coketo be used for blast furnace operations at the Ajaokuta Steel Plant, Nigeria.