EAF Dust Treatment for High Metal Recovery

摘要

Electric arc furnaces (EAF) generate much dust during operation, which contains very high percentages of zinc, lead, and iron, as well as toxic organic substances. It is difficult to landfill it for environmental reasons, and not desirable in terms of wasting metal. However, most of the EAF dust is not processed sufficiently to make it harmless and to recover valuable metals. Rotary kiln process is the main stream of present EAF dust treatment, but they still have the weakness of iron-including clinker disposal. Smelting reduction process has the advantages of almost complete metal recovery and detoxification of the dust, but it was not economically competitive because of higher energy cost. But the situation is changing with the increase of metal prices and severe environmental regulation. KATEC R6D Corporation in Taiwan and JP Steel Plantech in Japan have resolved this problem by developing a new electric smelting reduction furnace (ESRF) process. The first ESRF plant was constructed in Taiwan and started commercial operation in September 2010. This plant is working well as initially intended, achieving high levels of zinc and iron recovery, with no gaseous pollutant emission, and very low leaching of toxic heavy metals from slag.