Abstract: A method for making metal nuggets comprises heating a material containing a metal-oxide-containing substance and a carbonaceous reductant to reduce metal oxide in the material and then further heating the produced metal so as to melt the metal while allowing the metal to separate from a by-product slag component and to form granular iron. A cohesion accelerator for the by-product slag is mixed into the material to produce metal nuggets having a high metal purity, a large diameter, and superior transportation and handling qualities at a high yield and high productivity.

Abstract: An apparatus for producing liquid pig iron, including an iron oxide reducing furnace, a melting furnace positioned to receive and melt iron oxides reduced in the reducing furnace, a pig iron discharge device associated with the melting furnace, a slag discharge device associated with the melting furnace, at least one supply pipe connecting the reducing furnace and the melting furnace such that a mixture of metallized iron from the reducing furnace may be transferred to the melting furnace under gravity, and at least one discharge pipe connected to discharge combustion gases from the melting furnace to the reducing furnace, wherein the at least one supply pipe is provided with a plurality of regulating flap valves configured to allow sufficiently large accumulation of a mass of the mixture of metallized iron and to pour the mixture of metallized iron from a certain height such that the mixture of metallized iron being poured penetrates the pig iron in a molten phase forcefully.

Abstract: Solid state iron oxide reduction in a gas-solid reduction zone is combined with continuous melting of the hot solid reduced iron in a fuel-fired gas-solid-liquid melting zone within a rotary furnace by pneumatic transfer of the hot reduced iron by carrier gases through a transfer duct connected into an injection lance projecting into the melting zone and carrying a nozzle which directs a jet of hot reduced iron downwards into the metal bath, with a preferred embodiment of continually traversing the lance and thereby the jet of carrier gases and hot reduced iron longitudinally forwards and backwards enhancing heat transfer. The invention embraces a broad range of known solid-state reduction processes, classified either as: Group A. those employing gases within a gravity contact-supported or fluidized moving bed at substantial pressures of 1-5 atmospheres; or Group B. solid carbonaceous reductants in a rotary kiln or rotary hearth conducted at near ambient atmospheric pressure.

Abstract: A method of manufacturing a molten metal iron by charging a starting material at least comprising a carbonaceous reducing material and an iron oxide-containing material into a rotary hearth furnace, reducing under heating the charged starting material into a solid reducing iron, carburizing the metal iron in the solid reduced iron with the carbon ingredient in the carbonaceous reducing material, thereby melting the metal iron, separating the slag ingredient contained in the starting material by the melting, and discharging the molten metal alloy in the molten state as it is to the outside of the rotary hearth furnace for recovery, wherein a downward inclined surface is disposed at an angle 3 to 30° relative to the horizontal plane on the upper surface of a hearth of the rotary hearth furnace on which the starting material is placed, and the molten metal iron is discharged at the discharging position for the molten metal iron from the lowest portion of the inclined surface.

Abstract: In a method of recycling iron and steel industry waste by processing the waste as an object substance by the use of a rotary kiln, the object substance is changed into a valuable material while the object substance travels within the rotary kiln from an upstream side to a downstream side. The object substance is heated on the upstream side of the rotary kiln within a reducing atmosphere to be reduced and molten into a reduced and molten product. The reduced and molten product is quickly sent to the downstream side without being adhered to an internal wall of the rotary kiln. The valuable material is extracted from the reduced and molten product which may be directly discharged out of the rotary kiln or which may be discharged after the reduced and molten product is once kept in a basin formed in the vicinity of the downstream side of the rotary kiln.

Abstract: The process of the invention comprises gaseous reduction of iron oxides in solid state combined with concurrent melting of the hot reduced iron within a closed system without cooling down the charge or exposing it to the outside atmosphere. It incorporates the continuous recycling of a major portion of the off-gases from reduction, and fully utilizes the chemical heat contained in the fuel and reductant by substantially complete oxidation to CO.sub.2 and H.sub.2 O in the system gaseous reaction products and recovery of their sensible heat, prior to final exhaustion as waste gases. Features include dewatering of the off-gas from reduction, enriching with hydrocarbon and recycling a major portion, and separately combusting a minor portion for transfer of the sensible heat to the enriched major portion, and also usually the combustion of a second minor portion with oxygen as fuel for melting, with the sensible heat of these combustion products also utilized for heating the enriched and recycled portion.