| 摘要 |
<p>PURPOSE: An object of the present invention is to provide a direct reduction method which can improve productivity in a reducing process of a metal oxide by rapidly heating raw materials immediately after the raw materials are charged into a furnace, which forms a reducing atmosphere in a latter reducing period to prevent re-oxidization of the raw materials, and which can reduce the fuel consumption per unit product by burning a flammable gas generated from the raw materials, as well as to provide a rotary hearth furnace for carrying out the direct reduction method. CONSTITUTION: Raw materials, including a metal oxide and a carbonaceous material, are supplied into a rotary hearth furnace. Then, the raw materials are heated and reduced by burners, which are arranged to cause a strong stirring action for an atmosphere around the raw materials, in an early reducing period that is defined as a period during which 70 - 80 % of a total amount of a flammable gas generated from the raw materials is generated. In a latter period subsequent to the early reducing period, the raw materials are heated and reduced by burners arranged to cause a weak stirring action for an atmosphere around the raw materials, whereby a metal is manufactured. With the present invention, productivity can be improved and the fuel consumption per unit product can be reduced.</p> |
