| 摘要 |
<p>PURPOSE: To recover Cr, Ni, etc., in excellent electric power efficiency and high yield by appropriately controlling molten slag temp. and specific electric conductivity, at the time of recovering Cr, Ni, etc., by melting and reducing dust and sludge containing Cr and Ni oxides as the raw material in an electric furnace. CONSTITUTION: The dust, sludge, scale, etc., containing Cr and Ni discharged in a stainless steel refining work, etc., as the oxides used to the raw material are melted and reduced together with coke as reducing agent and slag-making agent of CaO, CaF2 , MgO, SiO2 , etc., in the electric furnace to recover the Cr and Ni oxides as the combined alloy thereof. In this case, the basic or acidic slag-making agent is added in the molten slag so that the specific electric conductivity of the molten slag in the electric furnace is in the range of 0.8-1.7Ω<-1> /cm at the molten slag temp. in the range of 1350-1500 deg.C to suitably adjust the CaO/SiO2 ratio of the molten slag. The electric current conducted in the molten slag effectively raises the temp. of the molten slag with the resistant heat and the oxides of Cr and Ni in the molten slag are efficiently recovered as the iron form shape of Cr and Ni.</p> |
