Degradation behaviour of weathered coal during handling for the COREX process of iron making

Degradation characteristics of weathered South Blackwater coal were tested by using a drop apparatus to minimize the fines generation during handling at the Gladstone Port for the COREX iron making process. The weathered coal samples after 1, 3, 6, 9 months and a year of weathering were tested with the drop apparatus to measure the percentage of fines generation. It was found that the rate of fines generation increases with the period of weathering. A series of drop tests were performed to confirm the critical drop height below which fines generation is minimal and the test results suggested that coal lumps dropped from above 3 m height should be avoided and replaced by smaller drop heights. Drop tests were also conducted to measure the stabilization effects on the rate of coal degradation. The cushioning effects with higher initial percentage of fines reduce overall coal degradation. The effects of different types of surface onto which the weathered coal samples were dropped with initial fines were determined by dropping onto a steel surface, conveyor surface and coal surface. These test results show that the different surfaces have different degradation characteristics.