Recycling of electric arc furnace dust into glass-ceramic

Electric arc furnace dust was vitrified by SiO2, NaCO3 and CaO. The glass-ceramic produced from steel making dust was investigated in three aspects; stability of compounds, microscopic structure and mechanical properties. Leaching tests on electric arc furnace dust showed that the amount of Zn and Cd exceeded the environmental regulatory levels and the tests on glass ceramics exhibited that these products were chemically so stable. X-ray diffraction studies on them indicated that dominant phase in most samples was wollastonite. Scanning electron microscopy images of glass-ceramics corroborated that general shapes of crystalline phases were dendritic. By applying heat treatment, hardness of the product was significantly reduced and their mechanical strength was extremely increased. It showed that produced glasses had an average of 800 Vickers microhardness (HV) and after transformation to glass-ceramic by applying heat treatment, it was reduced to 500 HV.