| 摘要 |
<p>PURPOSE: To reduce the inert consumption of electricity and to electrically smelt oxide raw material in a high desulfurizing capacity by maintaining slag composition in the suitable range in an electric smelting furnace. CONSTITUTION: At the time of recovering Ni and Cr-containing alloy by melting and reducing the oxide raw material consisting essentially of steelmaking dust and waste solution sludge in the electric smelting furnace to produce the slag having 40-70% (CaO+SiO2 ) slag composition, a basicity (CaO/SiO2 ) of the slag is made (1.7-2.0) and Al2 O3 concn. is made 8-20%, and the unit consumption of coke is maintained in the range of (250-320)kg/ton of metal. The blending ratio of the raw material is adjusted at the step of blending the raw material to become a prescribed slag composition according to the analyzed result just before supplying the raw material into the furnace. In the electric smelting furnace provided with Soderberg type self-baking electrodes, a specific electric conductivity of the molten slag is measured. The basicity of the slag is estimated from the measured value and the slag composition is supplied into the furnace according to the estimated result.</p> |
