Authors: Sameer Al-Asheh, Mohamad Alharahsheh, Shoaib Ahmed ,Meloni Stannie Perera, Mohammed Shadab, Mohammed Ali Al-Alibasha, Rudhra Balasubramaniam, Sara Adel Ramsis
Abstract: Electric arc furnace (EAF) is used for smelting of recycled steel scrap. During scrap smelting, dust is emitted from the furnace due to the high temperature of the smelting process. The dust is characterized by its fine particle size and high content of heavy metals including iron, zinc, lead, and cadmium in the form of metal oxides. Therefore, this dust is considered to be hazardous waste according to the Environmental Protection Agency (EPA). Huge amounts of this dust are accumulated worldwide (5-7 million ton per year). The dust also contains considerable amounts of chlorides (mainly sodium and potassium). The presence of these chlorides may complicate the extraction of valuable metals from the EAF dust, particularly during the electrolysis process. On the other hand, huge amounts of chlorinated waste plastic materials, such as poly-vinyl chloride (PVC), which are accumulated worldwide, form another environmental waste problem. This paper primarily dealt with the leaching process, before the pyrolysis process. Water was used as leaching agent. The effects of such different parameters as pH, temperature, multi stage, contact time and solid to liquid ratio on EAF dust leacheability were considered. As conducted experimentally, it was shown that simple metal leaching reduces the load on the pyrolysis process. In addition to that, conducting leaching before pyrolysis in comparison to conducting pyrolysis on its own is shown to be more cost efficient in terms of energy output and cost of fuel needed.
Keywords: EAF dust, pyrolysis, leaching, metals