The present invention addresses the problem, in methods for producing a metal or alloy by reducing a mixture that contains an oxide ore, of providing an oxide ore smelting method with good productivity and efficiency. The present invention is an oxide ore smelting method for producing a metal or alloy by reducing a mixture that contains an oxide ore, the method comprising at least: a mixing step S1 for mixing an oxide ore with a carbonaceous reducing agent; a mixture-molding step S2 for molding the mixture obtained to obtain a mixture-molded body; and a reducing step S3 for heating the mixture-molded body obtained at a specified reducing temperature in a reducing furnace.

Provided is a smelting method for producing metal by reducing a mixture that includes an oxide ore such as nickel oxide ore, wherein it is possible to improve productivity by raising the metal recovery rate as well as to inexpensively and efficiently produce high-quality metal. The present invention is a smelting method in which: an oxide ore and a carbonaceous reducing agent are mixed; the resulting mixture is heated and subjected to a reduction treatment; and metal and slag, which are reduction products, are obtained, wherein the reduction treatment is carried out in a state in which one or more surface deposits selected from carbonaceous reducing agents, metal oxides, and oxidation inhibitors are deposited on the surface of the mixture.

The present invention relates to a method and apparatus for producing reduced iron from ironmaking dust which contains iron oxide which is generated at an ironmaking plant, takes note of the rotary kiln reduction method which does not require pretreatment of the dust, and has as its problem the pursuit of facilities which achieve further improvement of heat efficiency and stable operation.

To solve this problem, the present invention is characterized by heating and reducing carbon-containing shaped materials in a single closed space in which an internal heat type rotary kiln and an external heat type rotary kiln are arranged in series and including at least the insides of the two rotary kilns during which making the reduced exhaust gas which is generated at the external heat type rotary kiln burn inside of the internal heat type rotary kiln.

A rotary hearth furnace includes: a furnace body which surrounds a ring-like space; a hearth portion which forms a bottom portion of the ring-like space and is rotatable in the rotational direction; a gas exhaust portion which discharges an exhaust gas generated in the ring-like space to the outside of the furnace body; an introducing portion; and a flow rate regulating portion. The introducing portion is disposed upstream of the gas exhaust portion in the rotational direction and introduces a pressure regulating gas into a non-heating section of the ring-like space. The flow rate regulating portion is disposed between the introducing portion and the gas exhaust portion and regulates a flow rate of a gas by adjusting an opening area of the non-heating section.

Disclosed herein is a reduced iron production method enabling heat to be input well into reduced-iron raw materials on a hearth covering material in a reduction-melting furnace to improve the efficiency of treatment thereof. The reduced-iron raw materials are set on the hearth covering material through their falls and reduced on the hearth covering material. The hearth covering material is constituted by carbon materials each having a particle diameter of 5 mm or less. At least 7 mass % of the carbon materials have respective particle diameters each being 0.1 mm or less. This restrains the reduced-iron raw materials from embedment into the hearth covering material.

Disclosed herein is a reduced iron production method enabling heat to be input well into reduced-iron raw materials on a hearth covering material in a reduction-melting furnace to improve the efficiency of treatment thereof. The reduced-iron raw materials are set on the hearth covering material through their falls and reduced on the hearth covering material. The hearth covering material is constituted by carbon materials each having a particle diameter of 5 mm or less. At least 7 mass % of the carbon materials have respective particle diameters each being 0.1 mm or less. This restrains the reduced-iron raw materials from embedment into the hearth covering material.

A rotary bed-type electric furnace includes a rotary bed configured to carry material, and a rotator configured to rotate the rotary bed so that material carried on the rotary bed passes through peripheral zones of the rotary bed-type electric furnace. The peripheral zones include a feeding zone configured to receive material on the rotary bed, a drying zone configured to dry and heat material by means of electrical energy, a heating zone configured to heat material by means of electrical energy, a cooling zone configured to lower the temperature of the material and configured to release gases from the material, and a discharging zone configured to discharge material from the rotary bed of the furnace.

The reduced iron manufacturing method of the present invention includes preparing an agglomerate by agglomerating a mixture containing an iron oxide-containing substance and a carbonaceous reducing agent, and preparing reduced iron by heating the agglomerate to reduce iron oxide in the agglomerate, characterized in that Expression (I) as follows is satisfied:
C.sub.fixX.sub.under105/O.sub.FeO51(I)
where O.sub.FeO is the mass percentage of oxygen contained in the iron oxide in the agglomerate, C.sub.fix is the mass percentage of total fixed carbon contained in the agglomerate, and X.sub.under105 is the mass percentage of particles having a particle diameter of 105 m or less with respect to the total mass of particles configuring the carbonaceous reducing agent.

A rotary bed-type electric furnace includes a rotary bed configured to carry material, and a rotator configured to rotate the rotary bed so that material carried on the rotary bed passes through peripheral zones of the rotary bed-type electric furnace. The peripheral zones include a feeding zone configured to receive material on the rotary bed, a drying zone configured to dry and heat material by means of electrical energy, a heating zone configured to heat material by means of electrical energy, a cooling zone configured to lower the temperature of the material and configured to release gases from the material, and a discharging zone configured to discharge material from the rotary bed of the furnace.

A rotary hearth furnace includes: a furnace body which surrounds a ring-like space; a hearth portion which forms a bottom portion of the ring-like space and is rotatable in the rotational direction; a gas exhaust portion which discharges an exhaust gas generated in the ring-like space to the outside of the furnace body; an introducing portion; and a flow rate regulating portion. The introducing portion is disposed upstream of the gas exhaust portion in the rotational direction and introduces a pressure regulating gas into a non-heating section of the ring-like space. The flow rate regulating portion is disposed between the introducing portion and the gas exhaust portion and regulates a flow rate of a gas by adjusting an opening area of the non-heating section.