Studies of the Factors Controlling the Formation and Development of the Porous Structure of Coke

Abstract

The influence of several carbonization variables on the porous structure of coke has been quantitatively determined using optical microscopy allied to computerized image analysis to determine details of the porous structure. Thus preheating of the charge was shown to result in coke with a greater number of smaller pores which are less widely spaced on average. Increasing the blend vitrinite reflectance generally reduces porosity and pore size whilst the pore-wall size shows little change although this dependence varies with different coals. Additions of low-volatile additives to the blend follows this same general pattern but with certain petroleum cokes and coals of volatile matter less than about 12.5% there is also an increase in the pore-wall size. It has been shown how the data so obtained can be used to formulate blends to produce cokes of specific structural, and hence strength, characteristics.