An apparatus for direct reduction of iron ore in a solid state including a pre-heating furnace for pre-heating iron ore fragments and biomass in briquettes of these materials to a temperature in the range of 400-900° C.; and a reduction assembly for briquettes from the pre-heating furnace. The reduction assembly includes a reaction chamber, a source of electromagnetic energy in the form of microwave energy, a wave guide for transferring microwave energy to the chamber for heating and reducing iron ore in briquettes from the pre-heating furnace, with biomass acting as a reductant, a source of an inert gas, pipework for supplying the inert gas to the chamber to maintain the chamber under anoxic conditions, and an outlet for discharging an offgas and any retained particulates that are generated in the chamber.

An apparatus for direct reduction of iron ore in a solid state including a pre-heating furnace for pre-heating iron ore fragments and biomass in briquettes of these materials to a temperature in the range of 400-900° C.; and a reduction assembly for briquettes from the pre-heating furnace. The reduction assembly includes a reaction chamber, a source of electromagnetic energy in the form of microwave energy, a wave guide for transferring microwave energy to the chamber for heating and reducing iron ore in briquettes from the pre-heating furnace, with biomass acting as a reductant, a source of an inert gas, pipework for supplying the inert gas to the chamber to maintain the chamber under anoxic conditions, and an outlet for discharging an offgas and any retained particulates that are generated in the chamber.

This electric furnace includes one or more upper electrodes, one or more bottom-blowing tuyeres, a mechanical stirrer equipped with an impeller, and a charging device which injects an iron oxide-containing iron raw material.

This electric furnace includes one or more upper electrodes, one or more bottom-blowing tuyeres, a mechanical stirrer equipped with an impeller, and a charging device which injects an iron oxide-containing iron raw material.

A method for manufacturing molten iron by melting a cold iron source in an electric arc furnace having a carbonaceous material-injecting device. The method includes, in the carbonaceous material-injecting device, while a carbonaceous material is injected with a carrier gas through a central portion of the carbonaceous material-injecting device, injecting a fuel and a combustion-supporting gas through respective outer peripheral portions of the carbonaceous material-injecting device. The carbonaceous material injected through the central portion passes through a cylindrical combustion flame generated by a combustion reaction between the fuel and the combustion-supporting gas and is injected into molten slag and molten iron.

In a method for producing a molten steel according to one aspect of the present invention, the solid-state direct reduced iron contains 3.0% by mass or more of SiO.sub.2 and Al.sub.2O.sub.3 in total and 1.0% by mass or more of carbon. A ratio of a metallic iron to the total iron content contained in the solid-state direct reduced iron is 90% by mass or more, and an excess carbon content Cx is 0.2% by mass or more to the carbons contained in the solid-state direct reduced iron. The method includes a step in a first furnace of melting 40 to 100% by mass of the solid-state direct reduced iron, and separating a molten pig iron having a carbon content of 2.0 to 5.0% by mass and a temperature of 1350 to 1550° C. and a slag having a basicity of 1.0 to 1.4 and a step in a second furnace of melting a remainder of the solid reduced iron together with the molten pig iron separated in the first furnace and blowing oxygen onto the molten material to decarburize into a molten steel.

In a method for producing a molten steel according to one aspect of the present invention, the solid-state direct reduced iron contains 3.0% by mass or more of SiO.sub.2 and Al.sub.2O.sub.3 in total and 1.0% by mass or more of carbon. A ratio of a metallic iron to the total iron content contained in the solid-state direct reduced iron is 90% by mass or more, and an excess carbon content Cx is 0.2% by mass or more to the carbons contained in the solid-state direct reduced iron. The method includes a step in a first furnace of melting 40 to 100% by mass of the solid-state direct reduced iron, and separating a molten pig iron having a carbon content of 2.0 to 5.0% by mass and a temperature of 1350 to 1550° C. and a slag having a basicity of 1.0 to 1.4 and a step in a second furnace of melting a remainder of the solid reduced iron together with the molten pig iron separated in the first furnace and blowing oxygen onto the molten material to decarburize into a molten steel.

A system and method of direct reduction of iron (DRI) is disclosed, having a reduction unit configured to reduce iron oxides to metallic iron; a process gas heater coupled to the reduction unit, the process gas heater configured to supply the reduction unit directly with a source of heated reducing gas, where the process gas heater is further configured to receive a synthetic combustion air stream for heating the reducing gas, the synthetic combustion air stream comprising a source of oxygen with essentially no nitrogen. A method of carbon dioxide emission reduction from a direct reduction of iron (DRI) process is also disclosed.

A system and method of direct reduction of iron (DRI) is disclosed, having a reduction unit configured to reduce iron oxides to metallic iron; a process gas heater coupled to the reduction unit, the process gas heater configured to supply the reduction unit directly with a source of heated reducing gas, where the process gas heater is further configured to receive a synthetic combustion air stream for heating the reducing gas, the synthetic combustion air stream comprising a source of oxygen with essentially no nitrogen. A method of carbon dioxide emission reduction from a direct reduction of iron (DRI) process is also disclosed.

A continuous process provides direct reduction of iron ore in a solid state. Briquettes of iron ore fragments and biomass are transported through a preheating chamber and preheated to a temperature of at least 400° C. The preheated briquettes are transported through a heating/reduction chamber that has an anoxic environment, and iron ore and biomass in the briquettes are exposed to electromagnetic energy in the form of microwave energy under anoxic conditions. Microwave energy generates heat within iron ore, and biomass acts as a reductant and reduces iron ore in a solid state, as the briquettes move through the heating/reduction chamber.