Oxidation of coal in industrial conditions. 3. Mechanical strength of coke

Abstract

The change in mechanical strength of coke is investigated as a function of the storage time of the coal from which it is produced. Considerable variability is noted in the limiting coal-storage time due to deterioration in strength of the coke produced. Accordingly, care must be taken in specifying different storage times for different coal stocks. When oxidized coal is employed, wear of the coke is aggravated, because its strength is reduced. Analysis of graphical and mathematical relationships indicates that, in both summer and winter, coal of moderate metamorphic development may be stored for the longest times in terms of loss of coke strength. The change in the coking properties of coal is assumed to depend on the ease of penetration of the plastic mass through the surface layer of rigid thermostable structure formed on oxidation. Improvement in the coking properties of bituminous coal on natural oxidation is attributed to the increase in expansion pressure.