Methods for melting and refining a powdery ore containing metal oxides

In a method for melting and refining a powdery or fine granular ore containing metal oxide comprising:

• (1) charging said ore and a reducing gas to a fluidized bed type of preliminary reducing furnace to preliminarily reduce said ore therein,
• (2) charging a powdery carbonaceus reducing agent into a preliminary treatment furnace to preliminarily treat or carbonize said reducing agent and reduced ore,
• (3) charging the preliminarily reduced ore heated at a high temperature and the preliminarily treated or carbonized reducing agent into a vertical melting and reducing furnace,
• (4) introducing air or oxygen-enriched air at elevated temperature into said melting and reducing furnace so that said ore is melted and reduced by said treated carbonaceous solid reducing agent and air or oxygen-enriched air, and
• (5) discharging molten metal and molten slag from the melting and reducing furnace,
• the improvement which comprises
• generating a first reducing gas at elevated temperature in a vertical melting and reducing furnace provided with upper and lower tuyeres,
• blowing a part of said first reducing gas discharged from said melting and reducing furnace into the preliminary reducing furnace to preliminarily reduce said ore therein and blowing another part of said reducing gas into said preliminary treatment furnace to preliminarily treat or carbonize said carbonaceous reducing agent,
• introducing the preliminarily reduced ore and the preliminarily treated carbonaceous reducing agent into said melting and reducing furnace via at least the upper of the tuyeres, and
• introducing air or oxygen-enriched air via at least the lower of the tuyeres.