Determining the strength of coke under crushing forces

Despite the many characteristics of coal relating to its use as blast-furnace fuel, few characteristics have been proposed to predict the productivity of the furnace and its coke consumption. Drum tests of coke permit ample assessment of its ability to withstand mechanical loads (in particular, abrasive and impact forces). At the same time, models of coke failure in the blast furnace indicate that the crushing forces on the coke play an important role. Thanks to those forces, the mean piece size of the coke declines as it falls though the furnace. The method used to determine the coke’s ability to withstand abrasive and impact forces has been codified in GOST State Standards (in terms of the strength indices M ₂₅, M ₄₀, and M ₁₀). However, there is no standard method for assessing the ability of the coke to withstand crushing forces. To address that deficiency, a compact system for determination of the coke’s ability to withstand crushing forces is proposed: it consists of a press for the creation of compressive forces; a matrix with a punch in which the coke sample may be placed; and an instrument for measuring the compressive force (the crushing force). Values of the compressive strength determined using the new system are presented for various coke samples.