According to the International Energy Agency (IEA)[1]  , the steel sector, among heavy industries, ranks first in CO2 emissions and second in energy consumption. Brazil is the largest steel producer in Latin America and the ninth largest in the world, according to the Instituto Aço Brasil[2] . This work aims to analyze existing standards and definitions for greener steel in Brazil and Europe in order to contribute to achieving the goals of the Paris Agreement [3].The steel industry faces major challenges to become more sustainable. Steel production is very carbon-intensive. This contributes significantly to greenhouse gas emissions.The industry is under pressure to reduce its carbon footprint. It needs to adopt more sustainable practices. A recent report emphasizes the importance of a low-carbon economy. [Green steel seeks to reduce carbon emissions. This is done by using renewable energy and sustainable materials. Green steel is a cleaner option than traditional steel. It is made with technologies that reduce gas emissions. Our goal is to make steel without much impact on the environment.4]

Nanocrystalline soft magnetic materials are widely used in the manufacture of magnetic systems of transformers, electric reactors, chokes, and other devices . High magnetic permeability and low magnetic losses are provided by the nanosized crystal structure of the materials [1]. In the material of the Finemet type with the chemical composition of Fe_73.5Cu₁Nb₃Si_13.5B₉, the average size of Fe-Si crystallites is of the order of 10 nm [2]. Such a structure is formed in the course of amorphous precursor crystallization, which is produced using the technology of rapid quenching from the melt. In this alloy, Nb is used for inhibition of grain growth. Other elements can also find their application as inhibitors  and they can be arranged in the order of increasing the efficiency of grain refinement: Cr, V, W = Mo, Nb = Ta, Zr. 

The Fe_73.5Cu₁M₃Si_13.5B₉alloys where M = Nb, W, Mo, V, Cr were melt in a vacuum induction furnace. A 25 μm thick and 10 mm wide ribbon with the amorphous structure was produced by the planar flow casting process. The ribbon was wound up onto ring-type cores with the 32 mm outer diameter and 20 mm inner diameter. The cores were subjected to annealing at the temperature T_a = 823 К. The thermomagnetic analysis was performed with the simultaneous recording of the temperature inside the core by a thermocouple and the inductance of the winding wound over the core. The initial permeability μ was calculated based on the inductance measurements at 1 kHz. The structural state of specimens was studied using transmission electron microscopy on a JEM 200CX microscope. The data for calculating the average size of grains and histograms of the size distribution was received based on the results of processing of the dark-fields images of 300 grains. X ray analysis was performed on a diffractometer D8 DISCOVER in copper radiation (Cu K_α1,2) with the Bragg-Brentano focusing device and graphite monochromator at the diffracted beam. The processing of data was carried out with the use of analytical FullProf program TOPAS 3. When estimating the average size of crystallites, the correction coefficient К = 0.89 was employed in the Sherrer equation. The volume fraction of amorphous phase was estimated based on two diffusion maxima. The error of determination of the lattice parameter a for Fe₃Si made up 0.0005 nm.

The paper presents the result of investigation of physical origin of different efficiency of impact that inhibitors exert on the structure and magnetic properties of nanocrystaline alloys Fe_73.5Cu₁M₃Si_13.5B₉ where M = Nb, W, Mo, V, Cr. It is shown that the efficiency is directly related to the solubility of inhibitory elements in αFe, which in turn affects the diffusivity of atoms. Upon slow migration of grain boundaries, the inhibitory atoms with a lower diffusivity, being concentrated near the front of moving boundary, provide a stronger drag [3]. The weakening of the effect manifests itself in the lowering of the onset temperature of crystallization, as well as in the increase in the rate of elevating temperature and in the peak temperature of the core heating. This in turn results in the increase in the grain size and volume fraction of stable crystalline phases.

The present study introduces an industrial-scale innovation for intensifying the iron ore sintering process through coal gas injection via a waste gas recirculation system. Coal gas, a byproduct generated during the coking process in coke ovens, is rich in combustible components such as hydrogen, methane, and carbon monoxide. Coal gas, injected into the upper layer of the sinter bed through a specially designed pipeline and nozzle arrangement within the recirculation hood, promotes a more uniform combustion front, enhances high-temperature retention, and improves heat transfer across the sintering bed. 

The process has been successfully implemented at the plant level and has shown clear operational benefits. Key improvements include a 5–10% increase in the yield of coarse sinter (+10 mm), a 1–2% reduction in fine particles (−5 mm), and a 1–2% gain in sinter mechanical strength. The mean sinter particle size also increased by several millimeters, contributing to better handling and blast furnace performance. Furthermore, solid fuel (coke) consumption was reduced by 3–5% per ton of sinter produced, demonstrating significant potential for energy savings. 

By partially substituting coke with cleaner-burning coal gas, the process also contributes to lower carbon emissions and reduced environmental impact. These improvements underscore the dual benefits of this technique: enhancing product quality and operational efficiency while supporting sustainability goals. Overall, coal gas injection through the waste gas recirculation system offers a robust, scalable, and cost-effective upgrade for integrated steel plant sintering operations.

Iron ore sintering is a critical agglomeration process in iron and steelmaking, enhancing the physical and chemical characteristics of raw materials to optimize blast furnace performance. The granulation stage, wherein fine iron ore particles are combined with fluxes, fuels, and binders, is pivotal in determining the quality of the final sinter. Conventional granulation methods typically employ ambient-temperature water, often resulting in suboptimal granule formation, uneven moisture distribution, and reduced permeability in the sinter bed. This study investigates the application of hot water, at temperatures ranging from 60°C to 95°C, during the granulation process to improve raw mix properties and sintering performance. The controlled addition of hot water raised the temperature of the green mix by at least 10°C, achieving final mix temperatures between 35°C and 45°C and a target moisture content of 7.5% to 8%. The modified process led to more uniform water dispersion and improved granule formation, as reflected by an increase in the balling index from 1.22% to 1.53%. The granulated mix was subsequently sintered under controlled suction conditions, resulting in enhanced sinter yield and higher production rates. Overall, the use of hot water in the granulation stage significantly improves process efficiency, granule quality, and the performance of the sintering operation.

Gas carburizing of solid steel is carried out by using a large amount of hydrocarbon in order to keep the furnace atmosphere as long as constant, because carbon from hydrocarbon is consumed for carburization of the steel surface and hydrogen remains in the furnace. In the present study, selective removal methods of H₂ were surveyed and fundamental experiment was done by using Proton Conductor SrZr_1-xY_xO_3-a , which was prepared by spark plasma sintering method; hydrogen gas was separated from wet simulated coke oven gas atmosphere at high temperature successfully.

Therefore, injection of hydrogen through the tuyers of the blast furnace is expected to reduce coke rate; this is a kind of bridge technology for conventional blast furnace system to hydrogen reduction furnace system.

 At the same time, reported method to selectively remove H₂ was also applied to bench scale furnace for gas carburizing of solid steel by using gas filter module made of poli-imido fiber tube. The control of the furnace atmosphere was very important to keep it constant, which was also studied numerically as well as experimentally. Finally, selective removal of H₂ from the furnace was verified experimentally and the flow rate of so-called “carrier gas” (hydrocarbons) could be reduced more than 75 % under the condition of the same quality of steel surface by the carburization treatment. As a result, exhaust gas volume could also be reduced and the burnt exhaust gas, namely, CO₂ emission was minimized.

Control of the blast furnace hearth lining is an important aspect in ensuring efficient and safe operation of blast furnace production [1, 2]. The furnace lining plays a key role in protecting the blast furnace from high temperatures and chemically aggressive slag melt. Early detection of areas of increased wear allows you to plan preventive maintenance, minimizing downtime and loss of productivity. The article describes the developed three-dimensional unsteady furnace hearth model based on thermocouple data. The model makes it possible to estimate the shape of the furnace hearth and the temperature distribution in the furnace brickwork in three-dimensional and two-dimensional (graphical) form. To assess the condition of the furnace lining, the readings of thermocouples installed in the furnace lining of the blast furnace in the area of the three lower belts of refrigerators were used. The specified mathematical model can be used to control the blast furnace process at any time after capital repair of the first category.

In [1, 2] based on modern concepts the results of many years of research on the development and implementation of a heat control system for refractory lining of a blast furnace hearth are presented. A system for monitoring the condition of the refractory lining of a blast furnace hearth is proposed, designed to prevent emergency situations. The duration of the blast furnace campaign, that is, the time from one major repair to another, ranges from 5 to 20 years. One of the reasons that can significantly shorten the campaign period is the breakthrough of liquid cast iron through the lining of the lower part of the blast furnace (hearth). The analysis of existing methods for monitoring the condition of the refractory lining of a blast furnace hearth and extending the duration of its campaign in the world is presented. A mathematical description, algorithm, and computer program for calculating two-dimensional temperature fields in any vertical and horizontal section of the blast furnace hearth lining have been developed. The calculation is carried out by solving the equations of thermal conductivity using the readings of a large number of temperature sensors (up to 700) mounted in the lining of the furnace between the refractory blocks. The calculation algorithm has been improved in terms of taking into account the complex profile of the lower part of the blast furnace using the counting theorem. A system for collecting, processing and transmitting information from temperature sensors to the program database is used. Continuous monitoring of temperature changes at each point allows you to determine the remaining thickness of the refractory lining or the appearance of a scull and warn the furnace staff about the beginning of the lining heat. The developed program interface allows the furnace master to use many additional monitoring functions, in particular, the history of sensor readings, remaining wall thickness, etc. The monitoring systems for the refractory lining of the blast furnace hearth are installed at five blast furnaces of metallurgical plants in China and six blast furnaces in Russia.

The exhaustion of natural resources (quantity and quality) and CO₂ emission controls are becoming increasingly important in steel industry.  A lot of steel engineers studied various means to decrease reducing agent at blast furnace for reduction of CO₂ emissions.  For example, injection of waste plastics and carbon neutral materials such as biomass into blast furnace is better alternative. Especially, biomass has novel advantage, namely, no CO₂ emissions, because of carbon neutral.  Production of carbon composite iron ore agglomerates having good reducibility and strength is becoming one of the most important subjects. 

   Carbon composite iron oxide pellets using semi-char or semi-charcoal were proposed in order to enhance the reduction rate of iron oxide at lower temperatures.  The carbonization was done under a rising temperature condition until arriving at a maximum carbonization temperature Tc,max to release some part of the volatile matter included (V.M.).  Starting point of reduction of carbon composite pellet using semi-charcoal produced at Tc,max = 823 K under the rising reduction- temperature condition was observed at the reduction temperature T_R = 833 K, only a little higher than Tc,max (823 K), which was the aimed phenomena.  As Tc,max increases, the emitted carbonization gas volume increases, while the residual V.M. decreases, and, as a whole, the total heat value of the carbonization gas emitted tends to increase monotonically.