Furnace Steel Research Articles

Renewable Electricity and Green Hydrogen Integration for Decarbonization of “Hard-to-Abate” Industrial Sectors

This paper investigates hydrogen’s potential to accelerate the energy transition in hard-to-abate sectors, such as steel, petrochemicals, glass, cement, and paper. The goal is to assess how hydrogen, produced from renewable sources, can foster both industrial decarbonization and the expansion of renewable energy installations, especially solar and wind. Hydrogen’s dual role as a fuel and a chemical agent for process innovation is explored, with a focus on its ability to enhance energy efficiency and reduce CO2 emissions. Integrating hydrogen with continuous industrial processes minimizes the need for energy storage, making it a more efficient solution. Advances in electrolysis, achieving efficiencies up to 60%, and storage methods, consuming about 10% of stored energy for compression, are discussed. Specifically, in the steel sector, hydrogen can replace carbon as a reductant in the direct reduced iron (DRI) process, which accounts for around 7% of global steel production. A next-generation DRI plant producing one million tons of steel annually would require approximately 3200 MW of photovoltaic capacity to integrate hydrogen effectively. This study also discusses hydrogen’s role as a co-fuel in steel furnaces. Quantitative analyses show that to support typical industrial plants, hydrogen facilities of several hundred to a few thousand MW are necessary. “Virtual” power plants integrating with both the electrical grid and energy-intensive systems are proposed highlighting hydrogen’s critical role in industrial decarbonization and renewable energy growth.

The Reduction Reaction Behavior of Steelmaking Dusts with Lignin under Different Atmospheres.

This study investigated lignin as a reducing agent instead of fossil carbon for the reduction of zinc oxide and zinc ferrite contained in steelmaking dusts. Three types of dusts from different steelmaking processes were considered: ferrochrome converter (CRC), electric arc furnace stainless steel (EAFSS) and electric arc furnace carbon steel (EAFCS). Zinc is primarily found in zincite phases within CRC dust, while EAFSS and EAFCS dusts contain franklinite and zincite phases as Zn-bearing minerals. The proximate analysis of lignin showed that the fixed carbon content is 28.9%. Thermogravimetric (TG) analysis coupled with differential scanning calorimetry (DSC) and mass spectrometry (MS) was used to study the reduction behavior of different mixtures of lignin and steel dusts under inert and air atmospheres. Simultaneously, the minimum ratio of lignin out of three different proportions required to achieve a complete reduction of franklinite and zincite phases into metallic zinc was identified. The results indicated that a 1.1 stoichiometric amount of lignin is sufficient for the complete reduction of zinc-bearing minerals into metallic zinc. In conclusion, lignin can be used efficiently for processing steelmaking dusts.

Experience of using evaporative cooling of graphitized electrodes to reduce their consumption in ore smelting furnaces

Consumable graphitized electrodes (GE) are widely used for supplying current to AC and DC EAF's, ore-smelting and indirectly heated electric arc furnaces. Due to large current, thermal and mechanical loads, their consumption in the structure of the cost of smelting in some cases, for example, in steel smelting reaches 30 %. Considering this, as well as the unstable global economic situation, when many enterprises use imported electrodes, solving the issue of reducing them is urgent. Foreign-made arc steel furnaces with a capacity of 100 tons and more successfully use evaporative cooling (EC) technology. Its use leads to a reduction in graphite consumption by an average of 10–15 %. However, for ore-thermal furnaces, no data on the experience of using EC GE has been found in the literature. The purpose of the work is to study the possibility of reducing the temperature and consumption of GE in arc ore-smelting furnaces when using EC technology. Experimental studies were carried out at the enterprise PC “AVISMA” (Berezniki), which includes three ore-smelting furnaces with a capacity of 100 tons. For the graphite electrodes used in these furnaces, modeling of their thermal state was performed with and without EC. Rational technological parameters of the cooling process were determined: water flow 1.5 m3/h and system turn-on time 5–15 minutes from the start of the current supply. An experimental design of the EC ring and a system for monitoring water and air flow have been developed. As a result of several heats, a decrease in the surface temperature of the GE was recorded when using EC with water on its side surface and a number of shortcomings were identified. Recommendations for improving technology and improving the design of the AI system are formulated

Evaluation of asphalt film thickness and heavy metal leaching of oxidizing slag used as an aggregate material in dense-graded asphalt concrete.

Electric-arc-furnace (EAF) steelmaking uses scrap iron and steel as raw materials. Scrap iron and steel originate from complex sources and may contain heavy metal components which can leach into the environment over time due to wear-and-tear. A by-product of the EAF steelmaking process is oxidizing slag, and approximately 1.2 million metric tons is produced every year in Taiwan alone. This study investigated substitution of natural aggregates with oxidizing slag in dense-graded asphalt concrete. We evaluated the water resistance and asphalt film thickness of the oxidizing slag substituted asphalt concrete and further explored the performance of oxidizing slag as paving material. We determined the dissolved and total amounts of heavy metals in the oxidizing slag, comparing these results with current regulatory controls to assess the environmental compatibility of the oxidizing slag. We found that due to the complicated sources of oxidizing slag, the basic properties should be analyzed on a batch-to-batch basis. Furthermore, we recommend trial mixing before upscaling the production of oxidizing slag substituted dense-graded asphalt concrete to confirm the mixing time required to achieve uniformity. The results also show that in comparison to natural aggregates used in asphalt concrete, oxidizing slag exhibits superior performance in terms of increased asphalt film thickness and improved water resistance. Furthermore, oxidizing slag as an aggregate material was associated with decreased heavy metal leaching and reduced environmental pollution. The results of the toxicity characteristic leaching procedure (TCLP) met regulatory requirements. However, the microwave-assisted aqua-regia digestion procedure showed heavy metal concentrations exceeding the monitoring standards for food crops. Considering environmental compatibility, it is recommended that controlling the total amount of heavy metals in oxidizing slag should be included in regulatory requirements. Furthermore, we should prohibit the use of materials such as oxidizing slag and other steel furnace slag in the roadways adjacent to edible crop farmlands.

Sustainable solutions for railway using recycled rubber

This paper introduces four innovative applications of waste rubber from scrapped tyres or conveyor belts in railway tracks. They include (a) a synthetic energy-absorbing layer of coalwash, steel furnace slag and rubber crumbs (SFS + CW + RC) for railway subballast, (b) a rubber inter-mixed ballast system (RIBS), (c) energy-absorbing rubber geogrids, and (d) a hybrid track incorporating tyre cells and elements of off-the-road truck tyres. Comprehensive laboratory and field tests have been conducted to investigate the geotechnical properties of these applications. Specifically, an empirical model was developed to predict the permanent deformation response of SFS + CW + RC mixtures that incorporate the effect of granular rubber and axial loads based on cyclic triaxial tests. Large-scale triaxial tests and field trials proved that RIBS exhibited improved energy-absorbing properties, sufficient shear strength and the promising ability to mitigate ballast breakage and stress distribution. A rubber geogrid with an optimal rib thickness of 10.6 mm was selected based on drop-hammer impact tests. The performance of the hybrid track was investigated using the National Testing Facility for High-speed Rail (NTFHR), from which it was found that the reinforced track had significantly less settlement, lateral deformation and ballast breakage than the traditional track.

Sustainable Performance of Recycled Rubber and Mining Waste Utilized for Efficient Rail Infrastructure

AbstractUtilizing waste byproducts from mining industries and recycled rubber as alternate materials in railway tracks promotes sustainability of transportation infrastructure, while also increasing track longevity by reducing ballast degradation. This paper provides an overview of two such applications including (i) rubber-intermixed ballast stratum (RIBS) by replacing 10% ballast aggregates with granulated rubber particles with the particle sizes carefully selected according to Australian Standards, (ii) synthetic energy absorbing layer using a mixture of steel furnace slag, coal wash and rubber crumbs to replace traditional capping layer. These materials when tested using large-scale triaxial apparatus and field trials proved that tracks with waste materials performed better than the conventional ballasted tracks by reducing ballast breakage and exploiting the higher damping potential of these materials. Though the vertical deformations of the track slightly increased by using these materials albeit within the specified standards, the overall stability improved by reduced dilation and track vibrations. Increasing the life of ballast layer can lead to long-term cost benefits by saving millions of dollars in track maintenance and provide environment benefits through minimizing quarrying of natural rock aggregates and reducing the carbon footprint of mining industries.

Reducing skid marks on steel slabs by developing an improved design scheme of water beam

Due to the existence of cooling water pipes and thermoduric skids in the walking beam type reheating furnace, skid marks always occur on the bottom of the steel slab and the quality of the steel slab is seriously affected. In this paper, the coupled heat transfer model among steel slab, water beam, furnace gas and furnace walls is established to accurately simulate the reheating process of the steel slab. The discrete ordinates method (DOM) is adopted to solve radiative heat transfer problem in reheating furnace. To get closer to the real situation, the relative movement between steel slab and thermoduric skid is taken into account strictly. The formation process of skid mark is clarified based on the calculated results of coupled heat transfer, and an improved design scheme for water beam is proposed to make the new skid marks produced after water beam dislocation not overlap each other, which effectively reduces the skid marks. Our study can provide helpful advising for the improvement of steel slab quality and the design of water beam structure in reheating furnace.

Determining the content of steel furnace slag in asphalt concrete

Steel furnace slag containing heavy metal components is covered by asphalt cement when it is used to replace natural aggregates in road paving. When such a pavement deteriorates as a result of wear by people and vehicles as well as washing by rain, the aggregates are worn away and the heavy metal components within can overflow on the road’s surface, forming rust spots. This phenomenon has been observed on many roads, leading the general public to question the validity of using steel furnace slag and whether this is in violation of a contract with the contractor. However, it is known from literature that such rust spots on a road surface may also be caused by natural minerals such as pyrite that are contained in natural aggregates. Unlike cement concrete, the slag cannot be separated from the mixture after hardening; however, the asphalt cement can be separated from the aggregates by using a solvent. In this study, separated aggregates are tested for pH value, magnetic attraction, and elemental composition in order to assess the usability of slag. Based on the findings and the characteristics of steel furnace slag, this paper proposes a method for detection of steel furnace slag in asphalt concrete, which is divided into two stages. In the first stage, core samples of asphalt concrete are obtained from the road site. The asphalt cement is separated from the aggregates according to AASHTO T164 and then the separated aggregates are analyzed in pH value and magnetic attraction tests. When one or both of the tests indicate steel furnace slag characteristics, that is, alkalinity or magnetism, then it is possible that the asphalt concrete sample contains steel furnace slag, and should be tested in the second stage for further confirmation. In the second stage, the separated aggregates are grinded to less than 0.075 mm (No. 200) and their elemental composition is analyzed. Based on the composition of steel furnace slag, when the analysis results indicate ≥30 % CaO and ≥10 % Fe2O3, it can be regarded that steel furnace slag has been used in the asphalt concrete.

Carbonated steel slags as supplementary cementitious materials: Reaction kinetics and phase evolution

With increasing interest in utilizing metallurgical slags for mineral carbonation, there is a need to find applications for carbonated slags. The scope of this study is to explore the utilization potential of carbonated steel furnace slags (SFS) as supplementary cementitious materials (SCM) to produce low-CO2 cement-based materials. Two different types of SFS are studied with comparable amounts of major oxides but significantly different mineral phase compositions. In the first phase of the study, several parameters that affect the CO2 uptake during mineral carbonation are considered (temperature, CO2 pressure, particle size, and duration) for the two slags namely, basic oxygen furnace slag (BOFS) and desulfurized slag (DeSS). Among the two slags, the DeSS exhibited significantly higher degrees of carbonation than BOFS, and the higher carbonation of DeSS is attributed to the presence of Ca as Ca(OH)2 rather than Ca–Si in BOFS. For both the slags, increase in temperature and CO2 pressure generally led to increase in the degree of carbonation. In the second phase of the study, 30 wt% of white Portland cement (WPC) was replaced by carbonated slags (used as SCM) in the cement mixture. The cement mixture with the BOFS carbonated at 60 °C and 1 bar CO2 pressure, as SCM, exhibited compressive strength comparable with that of WPC. Higher degrees and rates of carbonation under different conditions appears to have reduced their reactivities as SCM.

Non-destructive ultrasonic testing and machine learning-assisted early detection of carburizing damage in HP steel pyrolysis furnace tubes

During the operation of HP steel furnace tubes, structural deterioration occurs due to carburization mechanisms. Herein, machine learning models were employed to detect carburization damage in furnace tubes using ultrasonic signals. The microstructural and elemental analysis revealed phases like austenite, chromium carbide, and niobium carbide. Our volumetric fraction analysis showed that the harmful chromium carbide phase increased toward the tube wall thickness. Three machine learning models, namely Gaussian Naive Bayes (GNB), Kernel Naive Bayes (KNB), and Subspace Discriminant (SD), were used to analyze the ultrasound signals. The GNB model demonstrated the highest accuracy rate (99.2%) and high sensitivity for the dataset with 26 features and a K-fold cross-validation with K value = 5, arising as the most effective classifier for detecting carburization damage in HP steel. Our results underscore the efficacy of the combined use of ultrasonic testing and machine learning for detecting carburization in HP steel furnace tubes.

Prediction of chronic diseases among population caused by air emissions from mining and metallurgical plant

Purpose. To analyze the species composition and volumes of pollutants that entered the atmospheric air from ArcelorMittal Kryvyi Rih during 2014–2022 and negatively affect the environment and the population living in the territory near the enterprise. Based on the two-dimensional mass transfer equation, calculate the concentration fields of the main harmful impurities and assess the risk of chronic diseases for the population that is under long-term technogenic influence. The methods. The most significant statistical indicators were used to analyze the dynamics and trends of changes in the volume of pollutants. To find the concentration fields, the analytical method of solving the two-dimensional equation of impurity transport is applied. A non-threshold risk assessment model was used to predict the risk of chronic diseases for the population from polluted air by ArcelorMittal Kryvyi Rih. Findings. On the basis of descriptive statistics, the dynamics of changes in gross emissions of pollutants into the air from ArcelorMittal Kryvyi Rih for the years 2014–2022 were analyzed, it was shown that the decrease in emissions of pollutants into the air is related to the decrease in the production volumes of the main types products, as well as with the reconstruction and decommissioning of open-hearth steel furnaces and rotary-hearth furnaces. The resulting concentration field of nitrogen oxide, sulfur dioxide, and carbon monoxide determines the areas that are most affected by the man-made load of this enterprise. The risk of chronic diseases that may appear in the population during their lifetime in this territory due to constant exposure to those harmful impurities that enter the environment in the largest volumes from this enterprise has been assessed. The originality. Trends in changes in gross emissions of pollutants into atmospheric air from ArcelorMittal Kryvyi Rih have been established. A program for numerical calculation of the concentration field was created on the basis of the method of analytical solution of the equation of steady-state transport of pollution in a two-dimensional formulation. Computational experiments were conducted for relevant harmful impurities to assess the level of concentration and the risk of chronic diseases in the population. Practical implementation. Prediction the risk of chronic diseases for the population living near the industrial enterprises is a necessary tool for assessing the level of environmental safety.

A Study on Fire Retardant and Soundproof Properties of Stainless Steel EAF Reducing Slag Applied to Fiber Reinforced Cement Boards.

In recent years, cases of the improper utilization of steel furnace slag have been widely reported, resulting in a crisis of nowhere for recycled resources such as inorganic slag. The misplacement of resource materials that originally had sustainable-use value not only has a great impact on society and the environment but also greatly reduces industrial competitiveness. To solve the dilemma of steel furnace-slag reuse, it is critical to find solutions to the stabilization of steelmaking slag under the innovative thinking of the circular economy. In addition to enhancing the reuse value of recycled resources, the balance between economic development and environmental impact is also crucial. The high-performance building material could provide a solution based on a high-value market. With the development of society and the increasing requirements for quality of life, the requirements for the soundproof and fireproof performance of lightweight decorative panels common in cities have gradually become popular. Therefore, the high performance of fire retardant and soundproofing could be the main development focus of high-value building materials to ensure circular economic feasibility. This study continues the research results of the application of inorganic re-cycled engineering materials in recent years, and the application of electric-arc furnace (EAF)-reducing slag to the development of base materials for reinforced cement boards, in order to complete the development of high-value panels with fireproof and sound-insulation properties in line with the engineering characteristics of the boards. The research results showed the optimization of the proportions of the cement boards with EAF-reducing slag as a raw material. The proportions of EAF-reducing slag to fly ash at ratios of 70:30 and 60:40 all met the requirements of ISO 5660-1 Class I flame resistance; the sound transmission loss in the overall frequency band can reach more than 30 dB, which is higher by 3-8 dB or more than the same board with similar specifications (such as 12 mm gypsum board) in the present building-materials market The products could be developed into building partitions and ceiling decoration boards with high performance in terms of fire retardant and soundproofing values, and also reduce the use of natural raw materials by more than 35%. The results of this study could meet environmental compatibility targets and contribute towards greener buildings. This model of circular economics would achieve energy reduction, emissions reductions, and be environmentally friendly.

Phosphorus Partition Between Liquid Crude Steel and High-Basicity Basic Oxygen Furnace Slags Containing V2O5

The influence of V2O5 on the phosphorus partition between liquid crude steel and heterogenous basic oxygen furnace (BOF) slag with CaO/SiO2 = 4.2 was investigated at a temperature of 1600 °C in a middle frequency induction furnace. Thereby the phosphorus transfer from “steel to slag” as well as from “slag to steel” was studied over a holding time of 60 minutes. The measured results were shown as phosphorus partition and phosphorus capacity and compared with the experimental values from the literature. It was found that V2O5 in highly basic BOF slags decreases phosphorus partition and phosphorus capacity. In addition, the resulting slags were investigated using a scanning electron microscope (SEM).

A Study on the Fire-Retardant and Sound-Proofing Properties of Stainless Steel EAF Oxidizing Slag Applied to the Cement Panel.

Because of incomplete recycling resource management and technology development, inorganic sludge and slag has been misused in Taiwan. The recycling of inorganic sludge and slag is a pressing crisis. Resource materials with a sustainable use value are misplaced and have a significant impact on society and the environment, which greatly reduces industrial competitiveness. To solve the dilemma of EAF oxidizing slag recycled from the steel-making process, it is important to find solutions to improve the stability of EAF oxidizing slags based on the innovative thinking of the circular economy. We can improve the value of recycling resources and solve the contradiction between economic development and environmental impact. The project team intends to investigate the development and application of reclaiming EAF oxidizing slags blended with fire-retardant materials, which will integrate R&D work from four different aspects. First, a verification mechanism is carried out to establish stainless steel furnace materials. Suppliers must be assisted in conducting quality management for EAF oxidizing slags to ensure the quality of the materials provided. Next, high-value building materials must be developed using slag stabilization technology, and fire-retardant tests must be conducted on the recycled building materials. A comprehensive evaluation and verification of the recycled building materials must be undertaken, and high-value green building materials must be produced with fire-retardant and sound-proofing characteristics. Integration with national standards and regulations can drive the market integration of high-value building materials and the industrial chain. On the other hand, the applicability of existing regulations to facilitate the legal use of EAF oxidizing slags will be explored.

Застосування графітованих гнотових електродів на дугових сталеплавильних печах постійного струму

Застосування графітованих гнотових електродів на дугових сталеплавильних печах постійного струму

Application of graphitized wick electrodes in DC arc steel furnaces

Application of graphitized wick electrodes in DC arc steel furnaces

The influence of the addition of different kinds of slags on the friction and emission behavior of a commercially employed friction material formulation

Keeping sustainability and the circular economy in mind, numerous studies have been conducted on the feasibility of the utilization of industrial wastes in friction material formulations for braking applications. One such highly produced waste is slags from blast furnaces. The present work focuses on the friction, wear, and emissions behavior of a commercially employed friction material formulation observing the inclusion of three kinds of slags. Two types of slags were obtained from a blast furnace; the difference was the cooling method. The third type of slag was collected from a basic oxygen steel furnace. The prepared samples were tested in the form of pins on a pin on disc equipment at 1.51 m/s, 1 MPa, and ambient conditions to replicate a mild braking scenario. Irrespective of the type of slag, the addition of the wastes observed either a decrease or similar emissions when compared to the virgin formulation. The friction and wear were in the range comparable to that of the reference composition; the CoF for slag specimens ranged between 0.49 and 0.51 compared to 0.45 for the reference composition. On the other hand, by inspection of the worn surfaces of the pins, it was seen that the slag-containing specimens had compact and expansive secondary contact plateaus with the inclusion of slag particles in their composition. Through this preliminary analysis, the possibility of the utilization of different slags is highlighted, especially in an already implemented commercial formulation, paving the path for further testing and validation.

Waste slags as sustainable construction materials: a compressive review on physico mechanical properties

Rapid industrialization and urbanization in emerging nations have resulted in the accumulation of various industrial wastes. As a result, reusing and recycling these wastes into an economical, durable, and environmentally friendly building material may be the most effective means of mitigating their environmental impact. Such wastes are being dumped in greater quantities, which pollute the ecosystem and the land. As a result, its efficient use and management are required, which presents a global issue for its viable recycling and safe disposal. The current review examines the use of various slags, including cupola slag, electric arc furnace slag (EAFS), steel furnace slag (SFS), and ground granulated blast furnace slag (GGBFS) in the development of sustainable construction materials considering the potential of such waste in greener concrete composites towards eco-friendly infrastructure. In order to produce environmentally acceptable construction materials, these waste slags have been used as a partial and full replacement of cement, fine and coarse aggregate with or without supplementary materials ranging from 10 to 60% for cupola slag, 20 to 50% for EAFS, 10 to 50% for GGBFS, and 10 to 30% for SFS are suggested. This review will be an inclusion that helps readers to identify gaps in experimental viability, material characterization, and physico-mechanical behaviour of waste slags, pointing to the potential for application in the production of sustainable building materials.

Steel furnace slag aggregate for railway ballast: assessment of abrasion evolution by close-range photogrammetry

Electric Arc Furnace steel slag aggregate has potential for wider application in transport infrastructures. However, the use of steel slag aggregate in the railway ballast layer, as an alternative to natural high quality crushed rock, is still restricted in some countries. This is not consistent with the current sustainable construction paradigm. To demonstrate the potential of this material, in this study the authors characterized its morphology and performance, carrying out quantitative analyses on the abrasion and 3D morphology evolution of particles submitted to micro-Deval testing. The slag particles showed higher angularity and surface texture indices than a natural granite used as reference; retained these characteristics longer; and yielded comparable or lower surface wear. These findings support the potential use of slag aggregate as an alternative to railway ballast material.

Investigation of intergranular stress corrosion cracking in a failed 347H stainless steel furnace tube

A 347H stainless steel tube of a furnace of a hydroprocessing unit was cracked during operation shortly after the last shutdown. Both internal and external surfaces of the tube were exposed to sulfur compounds. Material characterization methods including tensile test, double loop electrochemical potentiodynamic reactivation test and fractography were used to investigate the failure causes. Based on stereo investigations, the external surface of the tube was identified as the crack initiation location. The microstructure evaluation and DL-EPR test showed that sensitization with a high DOS value of 18 occurred in the tube material. The sensitization has resulted in a dramatic reduction in the elongation parameter. Fractography examination exhibited a brittle fracture with presence of sulfide corrosion products on the fracture surface. Finally, due to the combination of the obtained results and additional observations including corrosion within grain boundaries and intergranular cracking, polythionic stress corrosion cracking was determined as the failure mechanism.