Effects of weathered coal on coking properties and coke quality

Determinations of weathered coal by petrographic methods, and coking tests in an 18-inch ($\text{≈}\text{1}\text{2}\text{m}$) test oven were used to quantify the effects of weathered coal on coking properties and coke quality. The results show that the presence of weathered coal causes a decrease in coke stability and coking rate and an increase in coke reactivity and coke-breeze generation. Because these effects contribute to increased costs in both the coke plant and the blast furnace, every effort should be made to reduce the amount of weathered coal in coking coal mixes.