Basic properties and comprehensive utilization of iron-containing sludge & dust in the steelmaking process

The utilization status of iron-containing sludges & dusts in eight domestic steel plants including typical EAF short route and BOF long route metallurgical processes was investigated,and the basic properties of iron-containing sludges & dusts were studied using X-ray fluorescence spectrometry,chemical analysis,size distribution analysis,X-ray diffraction,scanning electron microscopy and other analytical methods. The results show that the steelmaking sludges & dusts have high contents of Fe,Ca,and Zn. They can not only be recycled inside the steel plants,but also can be used to develop high value-added products,which relate to the chemical and materials industry. There are more differences in particle size,specific surface,and moisture for the sludges & dusts from different processes. And the iron is present as magnetite,ferrous oxide,hematite,calcium ferrite,and metallic iron,and zinc exists in zinc ferrite. Such above factors must be taken into consideration when the steelmaking dust is studied and utilized. At present,the proportion of steelmaking dust for sale is large and some is used as the sintering raw material,and a small portion of steelmaking dust is used for the slag forming agent. Considering the low utilization levels,relevant technology should be studied to utilize iron-containing sludge & dust efficiently.