The effect of changes in microscopic structures on coke strength in carbonization process

A tensile strength of a coke picked from different distance away from coke oven wall was experimentally measured to investigate the effect of carbonization process by using the diametral-compression test. Changes of the microscopic structure of the coke picked from different distance away from coke oven wall were also observed to evaluate the effect of those on coke strength. The tensile strength of the coke vertically picked from the distance of 0-60 mm away from coke oven wall was higher than one picked from the distance of 60-120 mm away from coke oven wall. The microscopic structure of the coke vertically picked from the distance of 0-60 mm from coke oven wall was more homogeneous than the one vertically picked from the distance of 60-120 mm away from coke oven wall. Furthermore, a fracture analysis using RBSM (Rigid Bodies-Spring Model) assuming diametral-compression test was carried out in order to investigate fracture behavior of the coke. Numerical results showed that the fracture started at the near center of analytical object and crack vertically propagates by shear stress and tensile stress. Strain-load curve of analytical result was in good agreement with one of experimental result. It is supposed that fracture analysis using RBSM assuming diametral-compression test can reproduce the fracture behavior of coke.