Factors affecting the mechanical properties of blast furnace coke

Michael G. K. Grant
The influence of coking conditions, with respect to position in a commercial coke-oven, on the mechanical behaviour of blast furnace coke has been studied. This involved the determination of density, porosity, the characterization of microstructure and assessing the influence of all three on the compressive strength of coke. The plastic flow properties were also investigated at temperatures greater than 1000°C. Three coke batches, originating in a 5m commercial coke-oven at three different
more » ... hree different positions with respect to height (0.8m, 3.3m and 5m below the coal line), along with three coke batches produced in a 460mm test-oven, were supplied by Energy, Mines and Resources (CANMET) in Ottawa. A warf coke batch was also provided as a control sample. Several hundred core-drilled specimens (≃1.3cm diameter and 1.3cm length) were produced from the seven coke batches. The bulk density of each cylindrical coke specimen was determined. Also, a detailed microstructural analysis, using a Leitz Image Analyzer, of the flat faces of the coke cylinders was performed to quantitatively characterize the pore and cell wall size, and the pore geometry. The compressive strength of each coke cylinder was determined both at ambient temperature and at 1400°C. In addition, the plastic flow behaviour of the commercially produced coke batches was studied. Results indicate that the coke product bulk density was affected by the coke-oven pressure (static load). Studies of the test-oven coke batches revealed that coke bulk density increased with higher oven pressure. Furthermore, the pore size was found to be larger for cokes produced at lower oven pressures. The cell wall size did not appear to be affected by coke-oven pressure. The bulk density of the commercially produced samples increased with depth below the coal line. This was attributed to a higher temperature and static load that existed at the bottom of the battery. The pore size was larger in cokes extracted from higher regions. No correlation of cell wall size with depth below the coal [...]
doi:10.14288/1.0078471 fatcat:a37bavuodfdzjbma5abp2fbr4y