Abstract: A method supplies reactants, including fuel gas, to burners that discharge the reactants into a furnace process chamber. In a stable flame mode of operation, stable flames are projected from the burners into the furnace process chamber. At a time when the furnace process chamber has a temperature at or above an autoignition temperature of the fuel gas, a diffuse combustion mode is initiated by supplying a selected burner with additional reactants, including reactants diverted from another burner, to blow off the stable flame at the selected burner.

Abstract: A rotary hearth furnace for treating metal oxide materials comprises a hearth mounted for rotary movement within an enclosure. One or more fuel burners are positioned above the hearth. The burners are operably fired to heat the furnace so that heat radiates toward the hearth. One or more oxygen nozzles are positioned between the hearth and the burners in a manner that avoids substantial contact between the oxygen and the briquettes, thereby creating a quiescent zone immediately above the briquettes, with the quiescent zone being sufficient to minimize reoxidation of the reduced briquettes, and minimize entrainment of particulate matter from the briquettes.

Abstract: A reduction treatment apparatus can include a reduction furnace configured to reduce zinc and/or iron oxide through heat treatment of zinc-containing iron oxide or zinc oxide or iron oxide, with a reducing material. The reduction treatment apparatus also has an oxide inlet configured to supply to the reduction furnace the zinc-containing iron oxide or zinc oxide or iron oxide. The reduction treatment apparatus further has a reducing material inlet configured to supply to the reduction furnace the reducing material. The reducing material can comprise at least one of ASR, shredder dust of home electric appliances, waste plastics, refuse derived fuel, refuse paper and plastic fuel, sludge, oil mud, chips of wood, thread debris, rubber debris, and animal and plant residues. The reduction furnace can be configured to use the reducing material as a heating material and reduce the zinc-containing iron oxide or zinc oxide or iron oxide without auxiliary fuel.

Abstract: A method for producing char and fuel gas includes degasifying a carbonaceous material with oxygen-containing gases in a fluidized bed reactor at a temperature of more than about 1000° C. and at a pressure of from about 1 bar to about 40 bar. A supply of oxygen within the fluidized bed reactor is adjusted so as to recover more than 60% of fixed carbon in the carbonaceous material in a char product, and an oxygen availability in a lower or bottom region of the fluidized bed reactor is less than 80% of an oxygen availability in an upper region of the fluidized bed reactor.

Abstract: Metallic iron nuggets made by reducing-melt of a material containing a carbonaceous reductant and a metal-oxide-containing material, the metallic iron nuggets comprising at least 94% by mass, hereinafter denoted as “%”, of Fe and 1.0 to 4.5% of C, and having a diameter of 1 to 30 mm are disclosed.

Abstract: Method and system for producing metallic nuggets includes providing reducible mixture (e.g., reducible micro-agglomerates; reducing material and reducible iron bearing material; reducible mixture including additives such as a fluxing agent; compacts, etc.) on at least a portion of a hearth material layer. In one embodiment, a plurality of channel openings extend at least partially through a layer of the reducible mixture to define a plurality of nugget forming reducible material regions. Such channel openings may be at least partially filled with nugget separation fill material (e.g., carbonaceous material). Thermally treating the layer of reducible mixture results in formation of one or more metallic iron nuggets. In other embodiments, various compositions of the reducible mixture and the formation of the reducible mixture provide one or more beneficial characteristics.

Abstract: The invention provides a method and apparatus for charging a raw material and a carbonaceous material, in which a reduced product generated on a hearth can be quickly melted for reliable separation into a metal and slag, and the metal and the slag can be easily discharged out of a furnace as individual small agglomerates. With the charging method and apparatus, when charging the raw material and the carbonaceous material onto the moving hearth of the moving hearth furnace, the carbonaceous material is first charged onto the moving hearth to form a carbonaceous material layer thereon. The raw material or a mixture of the raw material and a carbonaceous material is then charged onto the carbonaceous material layer to form a raw material layer thereon. A projection is then pressed against the raw material layer from above, thereby forming a plurality of recesses in the surface of the carbonaceous material layer.

Abstract: The present invention provides a reducing furnace of the rotary hearth-type and a method for reducing a metal oxide simplified in the process from dehydration to molding, according to which a moisture-rich powdery raw material is reduced at low cost. The present invention also provides an operation method whereby dusts or sludge generated in the refining or processing of metal are economically recycled.

Abstract: A rotary hearth furnace for reducing a feed material is disclosed. The rotary hearth furnace includes a rotating hearth disposed in an enclosure and mounted for rotary movement. The enclosure includes an annular inner wall, an annular outer wall and a roof. The enclosure is sealed to the hearth and divided into a plurality of zones including at least a loading zone, a process zone and a discharge zone. The furnace further includes a plurality of burners positioned in at least the outer wall of the enclosure to provide a controlled temperature within the rotary hearth furnace and a flue positioned within the reduction zone of the furnace between the preheat zone and the discharge zone to exhaust combustion gases from the burners and gases resulting from the processing of the feed material. Said flue contains space for combustion and settling of the unburned particulates.

Abstract: 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.

Abstract: A continuous process is provided for rapid melting of a variety of virgin and recycled ferrous and non-ferrous metals. This is accomplished by distributing the introduction of the unmelted charge materials and hence the melting heat requirements along an elongate gas-solid-liquid reaction zone within a rotary furnace, according to the distribution of heat available to effect melting. In the case of fine-sized metal charge materials, fluxes and additive reagents, this charge distribution is implemented by traversing of the nozzle jet, as directed to penetrate into the metal and slag bath from a solids injection lance, successively backwards and forwards and, in the case of coarse-sized materials, by traversing of the discharge from an oscillating conveyor.

Abstract: A method of pyroprocessing mineral ores, such as iron ore. The method includes receiving a preheated product stream of iron-containing pellets at an infeed end of a rotary kiln and introducing an oxidizing gas into the tumbling bed toward the infeed end of the rotary kiln. Additionally, a combustible fuel is introduced through ports above the tumbling bed such that combustion of the introduced fuel increases the temperature of the product stream toward the infeed end. The increase in the temperature of the product stream allows the intensity of the flame from the centerline burner to be decreased, resulting in a reduction in the production of NOx. The apparatus for introducing both the oxidizing gas and fuel into the rotary kiln are common with each other.

Abstract: A method for blowing a synthetic resin material into a furnace which comprises processing film-shaped synthetic resins into a first granular resin material; crushing non-film-shaped synthetic resins into a second granular resin material; pneumatically feeding the first granular resin material and the second granular resin material to a furnace; and blowing the first and second granular resin material into the furnace.

Abstract: A method and apparatus of introducing one or more reagents into a rotary and/or elongate kiln in which titaniferous material is being treated eg upgraded wherein the reagent(s) is introduced (I) at a plurality of locations along the length of the kiln and/or (II) at or adjacent to a discharge end of the kiln. The reagents may comprise one or more of chlorine-containing compounds, sulphur, sulphur-containing compounds, magnesium compounds, manganese compounds, fluxes and glass-forming reagents, including a borate salt or mineral. The reagent may be mixed with the discharge end coal or introduced separately.

Abstract: A process for beneficiating particulate titanium-bearing ore containing iron oxides is disclosed. The first step of the process entails prereducing the ore to convert about 20-90 percent of the iron oxides in the ore to metallic iron. Next, the prereduced ore is introduced into a mechanical reduction kiln and contacted with HCl and particulate carbonaceous reducing material. The turning and cascading of the materials in the kiln, in the presence of HCl and the reducing material, converts at least some remaining iron oxide in the ore to metallic iron and causes metallic iron to be liberated from the ore grains. Particulate metallic iron having a particle size of at least 50 microns is thereby formed. Finally, the particulate iron is separated from the ore.