Additive for the thermochemical treatment of molten iron in order to separate, distribute, agglomerate, precipitate, spheroidize and/or crystallize combined, solvated and/or colloidal carbon present in molten iron in the liquid state into graphite in its hexagonal diamond or Lonsdaleite form, in order to produce ductile, nodular, spheroidal, vermicular, coral, spheroidized or grey iron with superior mechanical properties, iron with high metal yield and zero contraction during casting; the additive comprises two or more elements in the metallic state selected from the S-block of periods 2 to 7 of the periodic table of elements; and two or more elements in the metallic state selected from F-block of periods 6 to 7 of the periodic table of elements. The additive makes it possible to produce cast iron parts with Type I and II spheroidal graphite in hexagonal diamond or Lonsdaleite form as per the ASTM-A247 standard.

Solar energy is concentrated and transferred to a heat transfer fluid, thereby heating the heat transfer fluid. The heat transfer fluid includes solid particles. Heat from the heat transfer fluid is used to melt a metal. While transferring heat to the furnace, at least a portion of the melted metal is oxidized to form steel. Heat is transferred from a first portion of the heat transfer fluid to a working fluid. The working fluid is then flowed through a turbine generator, which generates electrical power in response. A first water stream is electrolyzed using the electrical power generated by the turbine generator to produce a first oxygen stream and a first hydrogen stream. Heat is transferred from a second portion of the heat transfer fluid to a reactor that houses a recycling agent to thermochemically split a second water stream into a second oxygen stream and a second hydrogen stream.

A refining process control device includes: a past similar performance extraction unit configured to extract, from the refining performance database, a performance value of a past refining process in which a refining condition being a refining process condition acquired before the start of the refining process and including a result of an immediately preceding refining process in the refining facility, is similar to a refining process condition as a calculation target and the evaluation value is high; and an operation amount determination unit configured to determine an initial operation amount at the start of a refining process based on the performance value of the past refining process extracted by the past similar performance extraction unit, and determine an operation amount based on a change amount of the initial operation amount after the start of the refining process.

A method for manufacturing steel according to an embodiment of the present invention comprises the steps of: preparing a first molten metal manufactured using a first raw material including iron ore and a second molten metal manufactured using a second raw material including iron scrap; mixing the first molten metal and the second molten metal to manufacture a third molten metal; adjusting components of the third molten metal to manufacture a fourth molten metal; and manufacturing a product by processing the fourth molten metal.