| 摘要 |
<p>PURPOSE:To obtain a raw material for ultra high-speed hardening cement by melting and reducing a thermal slag incorporating CaF2 with the addition of reducing agent and sintering it by adjusting the composition after separating settled ferro-alloy. CONSTITUTION:The CaF2 incorporated thermal slag (e.g. dephosphorized slag) produced in the preliminary treatment of molten steel or steel refining stage is transferred into an electric furnace as shown in a figure and after melting and reducing it at 1300-1800 deg.C with the addition of reducing agent (e.g. powdery coke), settled ferro-alloy (Fe-Mn) is separated by gravity and removed from take-out port and adjusted to 0.1-5wt.% FeO+Fe2O3 content, 2.0wt.% MnO+Mn2 O3 content. Then, by adding alumina source (e.g. alumina ash) and lime source (e.g. quick lime) into the thermal slag from a hopper and after adjusting composition to 3-10mol Al2O3 and 0.5-17mol CaO per 1mol of CaF2, sintering is carried out at 850-1250 deg.C to obtain the raw material of ultra high-speed hardening cement (clinker) consisting essentially of 11 CaO, 7 Al2O3, CaF2.</p> |
