Influence of petrographic non-uniformity of coal and oxygen content in it on mechanical strength of coke

Decrease in quality of coals used for manufacturing the coke is observed at 'Nizhnetagil'skij Metallurgicheskij Kombinat' JSC. Smaller amounts of high-quality coals of K, KZh, KO, and OS grades are charged into coke ovens. Larger amounts of low-quality coals of KSN grade are utilized in charge materials. Low-quality partly oxidized coals are also utilized. This leads to increase in petrographic non-uniformity of the charge materials and to decrease in mechanical strength of produced coals. Mathematical model of strength of produced coke has been developed. Use of the model makes it possible to predict strength of the produced coke.