Improving the properties of high volatile coking coals by controlled mild oxidation

Both the fresh and oxidized coals were carbonized in a movable-wall oven of 17 kg capacity and the quality of the resulting cokes was tested by means of the JIS and ASTM standard methods. The results showed that, in certain cases, mild oxidation produced an improvement in coke quality. Oxidation also affected the porosity of the cokes, which may be related to the coke quality. It was found that the higher quality cokes had less macroporosity, whereas the lower quality cokes had a higher pore volume.