Methods of reducing copper metal content of shredded scrap steel are provided. The method includes continuously separating a first scrap steel fraction from an amount of scrap steel concurrently with separating a second fraction from the amount of scrap steel; continuously separating the second fraction and providing a nonmagnetic fraction and, concurrently, a third scrap steel fraction; grinding the nonmagnetic fraction followed by magnetic separation to provide a fourth scrap steel fraction and, concurrently, an enriched nonmagnetic fraction; continuously combining the first scrap steel fraction, the third scrap steel fraction, and the fourth scrap steel fraction to obtain a combined scrap steel product comprising scrap steel with reduced copper metal content; and introducing the combined scrap steel product to an electric arc furnace. Systems of reducing copper metal content of shredded scrap steel are also provided.

In some variations, the invention provides a biocarbon pellet comprising: 35 wt % to 99 wt % of a biogenic reagent, wherein the biogenic reagent comprises, on a dry basis, at least 60 wt % carbon; 0 wt % to 35 wt % water moisture; and 1 wt % to 30 wt % of a binder, wherein the biocarbon pellet is characterized by an adjustable Hardgrove Grindability Index (HGI) from about 30 to about 120, as shown in the Examples. The pellet HGI is adjustable by controlling process conditions and the pellet binder. The binder can be an organic binder or an inorganic binder. The carbon is renewable as determined from a measurement of the .sup.14C/.sup.12C isotopic ratio. Many processes of making and using the biocarbon pellets are described. Applications of the biocarbon pellets include pulverized coal boilers, furnaces for making metals such as iron or silicon, and gasifiers for producing reducing gas.

A charged material containing alloy iron of at least one of ferrochrome containing metallic Si or ferrosilicon, and unreduced slag containing Cr oxide generated by oxidative refining, is charged into an electric furnace as a mixture in which a mass ratio of a metallic Si amount to a Cr oxide amount is from 0.30 to 0.40, and a C concentration is in a range of from 2.0% by mass to a saturation concentration, and molten iron containing Cr obtained due to the Cr oxide undergoing reduction processing is produced, such that, when the charged material is heated and melted in the electric furnace, an attainment temperature is set to from 1400° C. to 1700° C., a maximum average heating rate in any 80° C. interval from 1300° C. to the attainment temperature is set to 15.0° C./min or less, and a minimum average heating rate in any 80° C. interval from 1300° C. to the attainment temperature is set to 3.0° C./min or greater.

A charged material containing a metal raw material of at least one of ferrochromium containing metal Si or ferrosilicon and unreduced slag containing Cr oxide generated by oxidation refining is charged into an AC electric furnace including three electrodes, a mass ratio of a metal Si amount to a Cr oxide amount being from 0.30 to 0.40, and a C concentration being from 2.0% by mass to a saturation concentration, and operation is performed under a condition where a diameter PCD (m) of a circle passing through the centers of the three electrodes viewed in a plan view from a central axis direction of the electric furnace, an average electrode height H.sub.e (m) that is a vertical distance from a tip of each electrode to a molten metal surface, a furnace inner diameter D.sub.f (m), a molten slag thickness H.sub.s (m), a spreading diameter D.sub.arc (m) of an arc on the molten metal surface, and a deflection angle θ (deg) of the arc satisfy the following relationships to produce molten iron containing Cr.

D.sub.arc=PCD+2H.sub.e.Math.tan θ

θ=52.5−75.Math.(PCD/D.sub.f)

0.22≤D.sub.arc/D.sub.f≤0.30

0.35≤H.sub.e/H.sub.s≤1.50

Method for the production of metal products starting from ferrous material, by means of an electric arc furnace.

A method for preheating metal pellets before charging into a melting furnace, wherein the pellets are transported by a conveyor belt to a chute and discharged from the chute into the melting furnace, the method including heating the pellets by direct flame impingement from two or more banks of burners, wherein the two or more banks of burners comprise an upstream bank of burners and a downstream bank of burners; and controlling the upstream bank of burners to operate oxygen-rich so as to create an oxidizing zone and the downstream bank of burners to operate fuel-rich so as to create a reducing zone.

Disclosed is a method for smelting low nitrogen steel by using an electric furnace. The smelting is performed using a dual-shell electric furnace, The dual-shell electric furnace has two furnace shells. An arc power system of the dual-shell electric furnace is used for alternatively electric heating on the two furnace shells, wherein when one of the two furnace shells is subjected to electric heating, feeding, sealing of a molten pool and blowing of a combustion medium and oxygen are sequentially carried out in the other furnace shell to start smelting. When the temperature of molten steel in the furnace shell subjected to electric heating reaches a target temperature, electric heating starts to be carried out on the other furnace shell. The method for efficiently smelting the low nitrogen steel by using the electric furnace of the disclosure, not only can shorten the smelting period and improve the throughput of a production line of an electric furnace, but also smelt low nitrogen steel to satisfy the requirements of the market on high-end steel. in addition, the method for efficiently smelting the low nitrogen steel by using the electric furnace of the disclosure can reduce the discharge of dust and smoke, thereby protecting the environment.

Methods and systems for determining a feed rate (unit mass/unit time) of metallic scrap material in real time being charged to an electric arc furnace (EAF) is provided, in which the methods and systems determine the speed of the metallic scrap material in real time and the volume of the metallic scrap material in real time. The methods and systems also classify the metallic scrap material via a machine learning model based on digital images of the metallic scrap material and assign a density to the metallic scrap material. The feed rate is determined based on the speed and volume of the metallic scrap material and the assigned density.

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.

An apparatus for supplying gas to a determinate number of injector devices of a melting furnace for the production of metal, including a main feed line, a first secondary feed line and a second secondary feed line which are respectively configured to supply, selectively and in a controlled manner, a process gas, an inert gas and a purge gas to each of the injector devices.