Blast furnace coke substitutes from Victorian brown coal

Iron is usually produced from its ores using coke in a blast furnace (BF). Coke, a hard and macroporous carbon material, is produced from special coals (coking coals) and acts as fuel, smelting agent, and the permeable support for the charge to the BF. No material can completely replace coke in a BF. Coking coals are becoming harder (and more expensive) to obtain. Victorian brown coal (VBC) is accessible, cheap, with low mineral concentrations, which is favourable for iron production in a BF. However, as-mined, it does not form coke, but a char which is too reactive to be used in a BF. The objective of this project is to produce a substitute for BF coke from VBC by physical and chemical treatments and to investigate the use of cementing agents to reduce the reactivity and strengthen the product finally formed. VBC from Loy Yang open cut, and its commercial products, briquettes and char, which were obtained from Australian Char Pty Ltd in lump form, were used as starting materials. VBC tar, coking coal tar pitch, and asphaltene (hexane insolubles from VBC tar) were used as binders. Some of the starting material was pre-treated by acid washing (0.5 M H₂SO₄), hydrothermal dewatering (HTD; 320 °C-35 min) or alkali treatment (KOH (aq), 185 °C-10 h). The elemental analysis and NMR of these materials were determined. Before pelleting, raw VBC, pre-treated VBC, or briquettes were dried at 105 °C under N₂, ground to