The structure and strength of metallurgical coke

This study aimed to investigate the relationship between the tensile strength of metallurgical coke and both the textural composition of the carbon matrix and the porous structure of the coke, and further to assess the use of these structural features as bases of methods of coke strength prediction. The forty-four cokes examined were produced in a small pilot-oven from blended-coal charges based on six coals differing widely in rank. Their textural composition was assessed by incident polarized-light microscopy while pore structural parameters were measured by computerized image analysis allied to reflected light microscopy. The tensile strength of coke could be related to textural data with accuracy using several relationships, some of which were based on a model for the tensile failure of coke. Relationships between tensile strength and pore sturctural parameters were less successful, possibly because of difficulties associated with the measuring system used. Neverthless relationships involving combinations of pore structural and textural data were developed and investigated. It was shown that relationships between tensile strength and calculated textural data had promise as the basis of a method of coke strength prediction. Also, tensile strengths could be calculated from the blend composition and the tensile strength of the coke produced from component cokes. Both methods have value in different situations.