Briquetting of carbon-containing wastes from steelmaking for metallurgical coke production

This work focuses on the manufacture of briquettes by using carbon-containing wastes from steelmaking as fillers and binders for use in coke ovens to produce metallurgical coke. Coal-tar sludges from the tar decanter of a by-products coking plant were employed individually as a binder or combined with other wastes, such as oils from the steel rolling mills and deposits from the coke oven gas pipelines. Another objective of this study was to use alternative low-cost fillers such as the coal generated after routine cleaning operations in the coal stockyards, so as to reduce the overall cost of briquette manufacture. Carbon briquettes with different formulations produced by a roll-press machine were tested in a semipilot movable wall oven by adding them to a coking blend at a ratio of 10 wt%. The quality of the cokes produced was assessed by measuring of their reactivity towards CO2 and mechanical resistance before and after gasification with CO2. In general, the coke quality parameters did not show any significant deterioration as a result of the addition of carbon briquettes when the amount and the nature of the binder and the particle size of the filler were optimized. Partial briquetting of the charge enabled cokes to be produced according to the specific requirements of blast furnace.