According to embodiments, disclosed is a method and system to maintain the soft and sparse slag characteristic favorable for an electric arc to efficiently transfer the energy to molten iron with the power input per furnace area higher than 600 KW/m2 while keeping FeO amount less than 5% in the slag and carbon amount higher than 2.5% in the product hot metal at a DRI melting furnace.

A method and system of extracting iron oxide from ore is provided, which may include adding a chelating agent to an iron ore to form an iron ore and chelating agent solution, heating the solution to reflux in water, and filtering the solution to yield an extraction residue and a chelated iron solution. The chelated iron solution may be treated with a potassium hydroxide and water solution to yield iron hydroxide.

A method for ironmaking by smelting reduction in a stir-generated vortex includes: (1) placing a pig iron in an induction furnace, and then heating the pig iron to a molten state to form a molten iron, and maintaining the molten iron to be greater than or equal to 1450° C.; (2) stirring a center of the molten iron to form a vortex with a height-to-diameter ratio of 0.5-2.5, and continuously performing stirring; (3) mixing and grinding on an iron-containing mineral, a reducing agent and a slag-forming agent in a mass ratio of 1:(0.1-0.15):(0.25-0.4) to obtain a powder mixture, spraying and blowing the powder mixture to a center of the vortex, performing a reduction reaction, and stopping the stirring after the molten iron and molten slags are obtained, wherein a waste gas is produced; and (4) discharging the molten iron and the molten slags respectively, and exhausting a treated waste gas.

The present disclosure relates, according to some embodiments to a method for steel production, the method comprising forming a hydrogen and a carbon from a natural gas using thermal plasma electrolysis; reducing iron ore fines with the H.sub.2 to form an iron briquette; melting the briquette iron from the furnace to form a melted iron and melted non-metallic slag; separating the non-metallic slag from the melted iron in the furnace; combining the carbon and the melted iron in a furnace to form a carbon black and iron mixture; and alloying the melted iron with the carbon black to form a steel.

A method and system of extracting iron oxide from ore is provided, which may include adding a chelating agent to an iron ore to form an iron ore and chelating agent solution, heating the solution to reflux in water, and filtering the solution to yield an extraction residue and a chelated iron solution. The chelated iron solution may be treated with a potassium hydroxide and water solution to yield iron hydroxide.

The invention relates to the use of pellets comprising one or more thermoplastic material(s) of more than 40%, based on the total dry weight of the pellets and one or more cellulosic material(s) of more than 20%, based on the total dry weight of the pellets, as a reducing agent in a process for making pig iron in a blast furnace. Said pellets can be provided in unground form, as a partial replacement of coke through the top of the blast furnace, or can be provided as reducing agent in the raceway in an amount of higher than 10 kg/ton iron.

The invention relates to a plant complex for steel production comprising a blast furnace for producing pig iron, a converter steel mill for producing crude steel and a gas-conducting system for gases that occur when producing the pig iron and/or producing the crude steel. According to the invention, the plant complex additionally has a chemical plant or biotechnological plant, connected to the gas-conducting system, and also energy storage for covering at least part of the electricity demand of the plant complex. Also the subject of the invention is a method for operating the plant complex.

The present invention provides a method of simultaneously recycling plastics and detoxifying chromite ore processing residue with residual heat from a steel slag. By heating and gasifying plastics with steel slag, followed by catalytically split-decomposing the plastics with catalysts such as chromite ore processing residue, the plastics are thoroughly converted into a energy gas under water vapor gasification. The surface coking of Chromite Ore Processing Residue is avoided. Meanwhile, the energy gas reduces Cr.sup.6+ in Chromite Ore Processing Residue into Cr.sup.3+, and the energy gas is cooled, and CO.sub.2 and Cl in the energy gas are adsorbed by alkaline substances in Chromite Ore Processing Residue. With this method, chromite ore processing residue is detoxified, and steel slag is cooled, furthermore, energy is saved and a energy gas is obtained.

In various aspects, systems and methods are provided for operating a molten carbonate fuel cell, such as a fuel cell assembly, with increased production of syngas while also reducing or minimizing the amount of CO.sub.2 exiting the fuel cell in the cathode exhaust stream. This can allow for improved efficiency of syngas production while also generating electrical power.

A process for the production of carburized sponge iron, including charging iron ore into a direct reduction shaft, and/or discharging carburized sponge iron from the direct reduction shaft, whereby a seal gas is introduced into the direct reduction shaft; removing a top gas from the direct reduction shaft; recycling a proportion of the top gas and mixing with a make-up gas to form a reducing gas; and introducing the reducing gas into the direct reduction shaft in countercurrent flow to the iron ore in order to reduce the iron ore and produce carburized sponge iron. The seal gas consists essentially of carbon dioxide, and the make-up gas comprises greater than 80 vol % hydrogen gas. Also provided is a system for the production of carburized sponge iron, as well as a carburized sponge iron produced by the aforementioned process.