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.

The disclosure discloses a method of operating an electric arc furnace, the method comprising capturing, from at least one facility of a steel mill, a heated metallurgical gas comprising water and carbon monoxide; conducting, by a reactor supply line, said metallurgical gas to a reactor; transforming, by a treatment of said metallurgical gas within said reactor, the carbon monoxide and water into hydrogen and carbon dioxide according to a water-gas shift reaction; and subsequently separating said hydrogen by a separation device. The method is characterized in that it further comprises providing an iron-bearing material, which comprises iron mainly in the form of iron oxide, to the electric arc furnace; at least partially melting the iron-bearing material to obtain a molten bath; conducting, by a furnace supply line, said hydrogen to the electric arc furnace, which is arranged downstream of the furnace supply line; and injecting, by a plurality of hydrogen injection devices, said hydrogen into said electric arc furnace, such that said hydrogen reacts as a reducing agent for reducing iron oxide in the molten bath during a smelting operation of the electric arc furnace.

Method for producing direct reduced metal material, comprising the steps: a) charging metal material (142) to be reduced into a furnace space (120); b) providing heat and a reducing gas into the furnace space (120), so that heated reducing gas heats the charged metal material (142) to a temperature high enough so that metal oxides present in the charged metal material (142) are reduced, in turn causing water vapour to be formed; and c) condensing and collecting the water vapour formed in step c in a condenser (280); The method is characterised in that, in step a), the metal material (142) is charged onto a gas-permeable floor (151), in that the reducing gas is circulated in a closed loop upwards through said floor (151), through the charged metal material (142), and further via said condenser (280) and a gas forced circulation device (250), and in that the method further comprises the step d) supplying additional reducing gas to achieve and/or maintain a predetermined pressure in said furnace space (120). The invention also relates to a system.

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.

The present disclosure is directed to an improved direct smelting process for improving the efficiency of energy/heat recovery from hot smelter offgas for the purpose of steam raising and power generation. In examples, the formation of alkali sulfate accretions in the temperature range 500-1000 C. are removed by introducing a mechanical sweep-cleaning system to an offgas duct of the smelter. The sweep-cleaning system comprises at least one central rotating shaft with chains, with each chain optionally having an accretion-removal member at its distal end. When rotated, the chains lift and the accretion-removal member sweeps the walls of the duct to remove the accretions.