Co-carbonization of oxidized coals with petroleum pitches

Abstract

Sherwood and Oakdale coals (NCB class 602 and 301a) were progressively oxidized in oxygen or air. The optical textures of cokes from carbonizations were monitored by optical microscopy. Fresh and oxidized coals were co-carbonized with three petroleum pitches of different modifying ability, i.e., superactive, active and passive. Increases in anisotropic optical texture of resultant cokes were monitored by a point-counting technique. Whereas all three pitches could remove the effects of mild oxidation it was only the super-active pitch which could modify cokes from the heavily oxidized coals. Modifying abilities of pitches can be explained in terms of their hydrogen-transfer capabilities. Suitable blending with pitches may enable oxidized coals to be used for making metallurgical coke.