| 摘要 |
<p>PURPOSE:To separation-recover iron, a Zn-rich substance which is not magnetically attracted and halogen cpds. from secondary dust discharged by reduction-calcining iron manufacturing dust contg. Zn by repulping the secondary dust with water followed by wet magnetic separation and solid-liquid separation. CONSTITUTION:Dust collected from a blast furnace, a sintering furnace, a converter, etc. is formed into pellets or briquettes, reduction-roasted, and reused as an iron source. Secondary dust contg. Zn 15-25% discharged by the roasting is repulped with water to dissolve CaCl2, KCl, etc. in the water, and the cpds. are recovered. The pulp is subjected to magnetic separation with a magnetic separator having a separation magnetic field intensity of 5000G or more to recover iron which is magnetically attracted. The pulp is then subjected to solid-liquid separation to recover a Zn>=50%-contg. substance which is not magnetically attracted, and the substance is used as atarting material for Zn. Residual halogen cpds. such as CaCl2, KCl2 and KCl are recovered from the separated liquid.</p> |
