Iron Production Research Articles

INNOVATIVE SOLUTIONS FOR IMPROVING THE EXISTING HEAT EXCHANGE EQUIPMENT OF METALLURGICAL ENTERPRISES

Considered issues regarding the refusal to use natural gas in the technological process of air heating in air heaters ofblast furnaces (coopers) of metallurgical enterprises. An innovative solution is proposed – a technological schemeusing a heat generator for heating flue gases and improving the system of their heat utilization in order to increase thetemperature of air and gas entering the air heater by 150–200°C. The results of the test trials of the technologicalscheme, which were carried out under the following conditions, are presented: calorific value of the mixture of naturaland blast furnace gas – 826.4 kcal/m3 (3,459.3104 KJ); calorific value of blast furnace gas – 750.7 kcal/m3 (3,142.43KJ); air consumption per unit of air heaters – 58 thousand m3/h; temperature of combustion components in front ofheat exchangers: air – 10 °С; fuel – 35 °C; smoke temperature: at the exit from the air heaters – 230 °C; in front of thechimney – 130 °C. The results showed that its application will ensure an increase in the average temperature of blastheating by 60-110°С without the use of natural gas, the duration of operation of heat exchangers can be increased byat least 10 years, and the technical and economic indicators of the blast furnace process will also improve. Theproposed innovative solutions will allow: to abandon the use of natural gas for air heaters; ensure coke savings up to14 kg/t; increase the average heating temperature of blowing by 110°C; stable, long-term provision of the necessaryair heating temperatures. The use of these technical solutions will allow to increase the production of cast iron andreduce the consumption of natural gas to increase the temperature of hot blasting. In the future, similar schemes maybe used in the fuel preparation system for multi-fuel boiler units of metallurgical enterprises

Putting the costs and benefits of carbon capture and storage into perspective: a multi-sector to multi-product analysis

Abstract Carbon dioxide capture, transport, and storage (CCS) is essential in achieving the net-zero target. Despite this increasing recognition, current CCS deployments are far behind targeted ambitions. A key reason is that CCS is often perceived as too expensive. While assessments of the costs of CCS have traditionally looked at impact at the plant level, the present study seeks to understand the costs and environmental benefits that will be passed to consumers via end-products and services. In particular, nine end-products/services (bridge construction, electricity from onshore wind power, electricity from offshore wind power, transport of a container via ship, a magazine, the production and transport of an avocado, a beer can, waste treatment via waste-to-energy, and long-distance air travel) connected to ten potential areas of application for CCS (cement production, iron and steel production, oil and gas production, natural gas processing, refining, ship propulsion engines, pulp and paper production, urea production, waste-to-energy, and direct air capture). The evaluations highlight that significant emission reductions (beyond 50%) could be achieved at marginal costs for end-users in six end-products/services: bridge construction, electricity from onshore wind power, electricity from offshore wind power, transport by ship, magazine, and waste treatment. Moderate emission reductions (between 11 and 37%) could be achieved in two cases at virtually no cost (increase below 1%): beer can and avocado production. Finally, only the case of using direct air capture to compensate for emissions from air travel was found to raise the cost for end-users significantly. Although more research is still needed in this area, this work broadens our understanding of the real cost and benefits of CCS and provides useful insights for decision-makers and society.

Vermicular and Chunky Graphite Nucleation during Chill Casting: Study on the Dynamics of Ductile Iron Recycling

AbstractThis investigation provides alternative insight into the dynamic behavior of spheroidal graphite structures throughout the remelting process during ductile cast iron recycling. Specifically, this study systematically analyzed the impact of the remelting process on graphite nucleation. Two approaches are included in this research: thermal analysis and the copper–mold chill casting method. Based on these results, different graphite structures nucleate in cast iron in response to the remelting and recasting processes, which correlate with the melting temperature, the cooling method, and the fading effect. Furthermore, it is indicated that the dissolution rate of spheroidal graphite is relatively slower than lamellar graphite, substantiated by the detection of residual graphite nodules in the case of low melting temperature applied during the remelting process. In addition, the formation of vermicular and potentially chunky graphite structures can also be observed to a certain extent during this set of investigations, thus providing further insight into their relation to the ductile cast iron production process. Graphical Abstract

A Discrete Brain Storm Optimization Algorithm for Hybrid Flowshop Scheduling Problems with Batch Production at Last Stage in the Steelmaking-Refining-Continuous Casting Process.

The iron and steel industry is energy-intensive due to the large volume of steel produced and its high-temperature and high-weight characteristics, sensors such as high-temperature application sensors can be utilized to collect production data and support the process control and optimization. Steelmaking-refining-continuous casting (SRCC) is a bottleneck in the iron and steel production process. SRCC scheduling problems are worldwide problems and NP-hard. The problems are not only important for iron and steel enterprises to enhance production efficiency, but also play a significant role in saving energy and reducing resource consumption. SRCC scheduling problems can be modeled as hybrid flowshop scheduling problems with batch production at the last stage. In this paper, a Discrete Brain Storm Optimization (DBSO) algorithm is proposed to handle SRCC scheduling problems. In the proposed DBSO, population initialization and cluster center replacement are specially designed to enhance the intensification abilities. Moreover, a perturbation operator is devised to enhance its diversification abilities. Furthermore, a new individual generation operator is devised to improve the intensification and diversification abilities simultaneously. Experimental results have demonstrated that the proposed DBSO is an efficient method for solving SRCC scheduling problems.

Life cycle assessment of a process integrating supercritical water gasification with direct reduced iron production

Life cycle assessment of a process integrating supercritical water gasification with direct reduced iron production

A Study of the Possibility of Producing Annealed and Metallized Pellets from Titanomagnetite Concentrate.

The current intensive development of steelmaking is being impeded by a scarcity of pure scrap. The potential to replace pure scrap with metallized raw materials that are naturally alloyed with vanadium and titanium, such as annealed unfluxed titanomagnetite pellets, could facilitate the achievement of key objectives in metallurgical development, particularly in the smelting of electric steel. The objective of this research was to produce annealed and metallized pellets from titanomagnetite concentrate under laboratory conditions, with the intention of further processing them as a commercial product in a blast furnace or as an intermediate product for the production of hot briquetted iron (HBI). The results demonstrate that pellets derived from titanomagnetite concentrate exhibit sufficient compressive strength (up to 300 kg/pellet) and a degree of metallization exceeding 90%, which aligns with the requirements for electric steelmaking. The suitability of pellets derived from titanomagnetite concentrate for use in both blast furnaces and metallization processes has been corroborated.

Waste refractory brick material added chitosan/oxidized pullulan complex gel production and removal of heavy metals from waste water

Wastewater is a by-product of numerous industrial processes that have been demonstrated to have adverse effects on human and natural health due to the pollutants it contains. The pollutants in these substances are organic or inorganic molecules and heavy metal ions that significantly harm the environment and human health. A variety of techniques have been devised for the removal of heavy metal ions from wastewater. The adsorption process has attracted significant attention due to its straightforward implementation, cost-effectiveness, and the environmentally friendly production of adsorbent materials using biocompatible substances. In this study, the removal of Cu2+ ions from wastewater was conducted using chitosan pullulan, a biocompatible and biodegradable polymer. In addition to chitosan and pullulan, waste refractory materials from a furnace used in iron and steel production were added to these polymer materials to increase the adsorption capacity. The initial step involved grinding the waste refractory brick material. Subsequently, chitosan was dissolved in acetic acid. After that, the refractory material was suspended in this solution, facilitating the formation of hydrogel beads using a NaOH solution. The obtained hydrogels were coated with pullulan to produce polyelectrolyte gel. Pullulan was oxidized to 6-carboxypullulan by the TEMPO (2,2,6,6-Tetramethylpiperidin-1-yl)oxyl) oxidation method and the negatively charged groups in its structure interacted with the positively charged groups in the chitosan structure to produce a complex gel. The chemical structure, morphological analysis, thermal analysis, and water release analysis of the produced waste refractory brick material added chitosan/oxidized pullulan complex gels were examined. The impact of the 6-carboxypullulan coating on the gels’ properties was elucidated. Furthermore, the adsorption of Cu2⁺ was conducted using solutions containing 100, 500, and 1000 ppm Cu2⁺ ions. It has been observed that the material can clean water with over 98% efficiency, even in solutions that exceed the standards set for wastewater. The material’s efficacy in cleaning solutions with concentrations above the standard for wastewater cleaning is evidence of its high performance. Furthermore, the kinetics and isotherm of the adsorption reaction were examined. The kinetics were determined to be consistent with the Pseudo Second Order (chemical reaction controlled) and aligned with the Langmuir and Freundlich Isotherm (mixed adsorption occurred on homogeneous and heterogeneous surfaces).

Advanced Ancient Steelmaking Across the Arctic European Landscape

Abstract This article presents results that seriously challenge conventional frameworks regarding the time, course, and cultural context of the introduction of iron and steel in Europe, in turn central metals in the narrative of civilization development. From focusing on 2,000-year-old finds from 42 different sites across the national borders of present-day northernmost Norway, Finland, and Sweden, our study reveals advanced iron and steel production contemporaneous with Roman steel production within the hitherto unthinkable cultural context of hunter-gatherers. By employing archaeometric analyses alongside a lens that considers the Arctic climate and landscape, long-standing inadequate interpretative frameworks are challenged and we manage to shed novel light on the metallurgical practices and skills of the ancient Arctic hunter-gatherers. By examining local conditions, the research specifically reveals adaptation strategies and previously underexplored social and organizational aspects of early ironmaking. The implications of these findings are profound, urging historians and archaeologists to adopt similar methods and perspectives to potentially uncover additional “unthinkable” locations/regions or contexts with advanced and early metalworking.

Sedimentary geochemistry in P-limited freshwater drained marshes (Charente-Maritime, France): Original drivers for phosphorus mobilization

Phosphorus bioavailability is a major issue in aquatic environments, where it generally limits primary production. In this work, the analysis of the pore water and the solid phase of the sediment was carried out over a 9-month monitoring period between February 2020 and April 2021 in two drained marshes (Marans and Genouillé, France) distinct by their uses and management tools. Soluble reactive phosphorus (SRP) enrichment in the sediment was intimately controlled by iron oxide dissolution. The latter seemed highly controlled by seasonal nitrate inputs (winter and early spring) that favoured denitrification as a major benthic mineralization process promoting iron curtain development and stability. Following benthic mitigation of nitrate other anaerobic metabolisms developed such as iron dissolutive reduction promoting P recycling and planktic bioavailability. Surprisingly, sulphur cycle seemed to affect P dynamics, especially in the absence of nitrate. The absence of NO3− triggered high sulphate reduction rates in the two first centimeters depth, reaching −8.9 E−03 ± 0.5 E−03 and -5.0 E−03 ± 0.2 E−03 nmol cm−3 s−1 in August and July at Marans and Genouillé respectively. These values placed this process at higher rates than the denitrification (maximum in May at Marans with −5.0 E−03 ± 1.1 E−03 nmol cm−3 s−1) and reduced iron production (maximum in July at Genouillé with 0.5 E−03 ± 0.1 E−03 nmol cm−3 s−1). The rapidity with which process changes occur (monthly scale) testified to the dynamism of these systems. The similarity in geochemical patterns regarding NO3− pressure at both sites underlines the importance of diffuse pollution in coastal systems for nitrogen mitigation and phosphorus trapping. The results obtained in this study could lead to the development of a generalized diagenetic operating model for temperate systems with high agricultural pressure. This would enable to target management efforts to both optimize the purification function and limit eutrophication risks in these systems.

Can Australia Become a Green Iron Powerhouse?

AbstractAs a country with an abundance of renewable resources, Australia has an opportunity to emerge as a global leader in the production of green iron rather than simply extracting and exporting iron ore around the world. While it makes sense to do so in the changing geopolitical environment, and to assist in achieving our commitments to dramatically reduce our carbon emissions, this paper sheds light on the complex technical and economic arguments for the creation of a green iron industry here in Australia. We argue that targeted government intervention coupled with industry commitment to transforming the sector could realistically result in the emergence of a nascent green iron industry in the medium term.

Examining the Effects of Ailing Ajaokuta Steel Plant on Industrialization and Technological Growth in Nigeria

Nigeria, out of the exigency to feed her bulging population established a mega iron and steel complex in Ajaokuta, Kogi state to drive technological innovation for productive activities in the country. The steel project was designed to serve as a catalyst for growth and development of industries as well as other sectors of the Nigerian economy. While the existing literature is replete with studies focusing on the factors undermining the operations of Ajaokuta Steel Plant, the effects of underutilized Ajaokuta Steel Plant on the Nigerian economy has received less academic attention. It is against this backdrop that the study examined the effects of ailing Ajaokuta Steel Plant on industrialization and development of technology in Nigeria. The study relied on documentary method of data collection and qualitative descriptive method of data analysis. The study revealed among others that the ailing state of Ajaokuta Steel Plant has adversely affected the growth of indigenous technologies and industries in Nigeria. The failure of the Ajaokuta Steel Plant to produce iron and steel products for the creation of indigenous means of labour has made the Nigerian economy an outrageous consumer of foreign techs and manufactured products. This has not only halted country’s quest for industrialization but has truncated its ability to manufacture what it consumes.

Advancing carbon-neutral iron production: Non-equimolar diffusion kinetics of coke with H2O in hydrogen-rich blast furnaces

This study presents a non-equimolar diffusion model to enhance the predictive accuracy of coke degradation kinetics in hydrogen-rich blast furnaces, where elevated water vapor (H2O) levels are present. The model integrates the unreacted core shrink model with the Maxwell-Stefan equation to delineate the 3D curved surface distribution of H2O concentration and the effective diffusion coefficient within the coke ash layer. Validated against experimental data, the model demonstrated a significant improvement in accuracy, with a deviation range of 0.77%-3.5%, compared to the 15.61%-18.92% deviation for the traditional unreacted core shrink model. This advancement is crucial for optimizing blast furnace design and operation, supporting the industry's transition toward low-carbon ironmaking. The findings highlight the importance of considering non-equimolar diffusion in the reaction kinetics between coke and H2O, contributing substantially to the scientific understanding and technological advancement in ironmaking.

A systematic review of decarbonization pathway and modeling conception in iron and steel industry at micro-, meso-, and macro-levels.

To meet the carbon-neutral goal in 2050, an accelerated transition of decarbonization is needed in the iron and steel industry. Lots of decarbonization path models are recently being used to analyze the technology pathways, industrial structure adjustments, and short- or long-term policies for greenhouse gas emission reduction. Thus, systematic insight is required for better making sense of the status quo and differences in low-carbon transition pathways at different levels. This paper reviews the carbon emission reduction of steel production routes and summarizes the decarbonization models from micro-, meso-, and macro-level perspectives, respectively. First, we systematically analyze the capacity and potential of both available and emerging technologies in the iron and steel production process. Additionally, we conduct a theoretical analysis of the bottom-up models currently used as effective tools to assess decarbonization technology pathways. Subsequently, pathways and models in terms of industrial synergy are elaborated. Policy guidance and market support are explored to overcome the challenges of collaborative carbon reduction faced by global steel producers. The characteristics of top-down models for supporting carbon reduction are also discussed. Finally, gaps in the literature and future research agendas are identified. Advancing this research could enrich discussions on steel industry decarbonization and provide clearer assessments of modeling approaches. The results indicate that existing energy-saving technologies in the iron and steel industry have limited carbon reduction capacity. Significant reduction requires coordinated efforts with upstream and downstream industries, particularly in hydrogen and power sectors, along with financial support and favorable policies.

Fuel use in medieval iron production in central Jutland, Denmark

Fuel use in medieval iron production in central Jutland, Denmark

Global trade of green iron as a game changer for a near-zero global steel industry? - A scenario-based assessment of regionalized impacts

The currently most promising approach for reducing CO2 emissions of the global steel production is reducing iron ore in shaft furnaces with (green) hydrogen instead of blast furnaces. Unlike to the liquid iron produced in blast furnaces, the direct reduced iron produced in this route (green iron) exists in a solid state and can be transported at reasonable costs over long distances. This allows for spatial decoupling of the iron reduction step from the steelmaking step and may lead to global trade in green iron as a new intermediate product in the steelmaking value chain. This article assesses the potential impact of a global green iron trade in terms of shifting energy demand between regions and in terms of cost savings by comparing three scenarios for a global near-zero GHG steel industry: The Domestic scenario, assuming strict regional co-location of green iron and steel production; The Max Trade scenario, assuming early emergence of a global green iron market and the Intermediate Trade scenario, assuming late emergence of a global green iron market. In the trade scenarios, 12-21% of global crude steel is produced from traded green iron in 2050. 15-26 Mt/a of hydrogen consumption is relocated to global “sweet spots”, resulting in cost savings of 2.2-3.9% of the global annual steel production costs, which can provide important support for the development of net zero steel production. Enablers and barriers for global green iron trade are discussed.

HR-GO

Context. Dwarf galaxy streams encode vast amounts of information essential to understanding early galaxy formation and nucleosynthesis channels. Due to the variation in the timescales of star formation history in their progenitors, stellar streams serve as ‘snapshots’ that record different stages of galactic chemical evolution. Aims. This study focusses on the Cetus stream, stripped from a low-mass dwarf galaxy. We aim to uncover its chemical evolution history as well as the different channels of its element production from detailed elemental abundances. Methods. We carried out a comprehensive analysis of the chemical composition of 22 member stars based on their high-resolution spectra. We derived abundances for up to 28 chemical species from C to Dy and, for 20 of them, we account for the departures from local thermodynamic equilibrium (NLTE effects). Results. We confirm that the Cetus stream has a mean metallicity of [Fe/H] = −2.11 ± 0.21. All observed Cetus stars are α enhanced with [α/Fe] ≃ 0.3. The absence of the α-‘knee’ implies that star formation stopped before iron production in type Ia supernovae (SNe Ia) became substantial. Neutron capture element abundances suggest that both the rapid (r-) and the main slow (s-) processes contributed to their origin. The decrease in [Eu/Ba] from a typical r-process value of [Eu/Ba] = 0.7–0.3 with increasing [Ba/H] indicates a distinct contribution of the r- and s-processes to the chemical composition of different Cetus stars. For barium, the r-process contribution varies from 100 to 20% in different sample stars, with an average value of 50%. Conclusions. Our abundance analysis indicates that the star formation in the Cetus progenitor ceased after the onset of the main s-process in low- to intermediate-mass asymptotic giant branch stars but before SNe Ia played an important role. A distinct evolution scenario is revealed by comparing the abundances in the Ursa Minor dwarf spheroidal galaxy, showing the diversity in – and uniqueness of – the chemical evolution of low-mass dwarf galaxies.

Promising directions for reducing CO2 emissions in production of vanadium cast iron

Promising directions for reducing CO2 emissions in production of vanadium cast iron

EVALUATION OF CARBONATED PRODUCT FROM MINERAL CARBONATION OF MINING WASTE FOR CARBON SEQUESTRATION

Mining operations generate significant quantities of waste containing alkaline earth silicates, which are valuable for carbon sequestration. Hence, the goal of this study is to assess the possibility of using mining waste to store carbon through a process of mineral carbonation. The study tested mineral carbonation under low reactivity conditions, including ambient pressure and low temperature, to evaluate the effect of pH levels on process efficiency. The samples were discovered to have an alkaline pH, suggesting that they were suitable for mineral carbonation reactions from the beginning. The carbonation process of the mineral was conducted at different pH levels of 8, 10, and 12. The findings showed that the carbonation efficiency was approximately 3%, with the highest level observed at pH 12. Through thermogravimetric analysis, it was observed that there was a multi stage transformation of minerals, which indicated the formation of carbonates containing iron and magnesium. The process captured approximately 33 and 39 g of CO2/kg. The process indicates that mine waste can be used as a source material for mineral carbonation, as demonstrated by the formation of iron and calcium carbonate products. This research demonstrates that mine waste has the potential for long-term carbon storage, offering a beneficial method for waste management and carbon capture strategies.

Investigation on the effectiveness of a new hoof care product to sustainably reduce and prevent Digital Dermatitis in dairy cow herds

The regular application of hoof care and cleaning products is an important part of protocols designed to reduce burden of disease caused by the ubiquitous and multifactorial hoof disease Digital Dermatitis (DD) in dairy cows. Commonly used hoof care products such as formalin or copper sulfate applied through foot baths or by spraying hindfeet are often irritant to the skin as well as harmful to the environment or human health while scientifically proven evidence of their efficacy is scarce. Thus, in a clinical controlled trial, we investigated if the use of a hoof care product based on a mix of iron complex salts, zinc salts and aluminum designed to reduce bacterial load on the skin and to support the natural skin barrier, was able to sustainably reduce disease severity and prevent new cases in 132 cows in 2 dairy herds (n1 = 72, n2 = 60) in Germany. From Dec 2021 to Dec 2022 only one predefined hind foot of every cow was washed and sprayed with the product twice a week (treatment group), the other hind foot was only washed (control group). Heifers joining the herd were sprayed for at least 4 weeks beforehand according to the same treatment and control regimen. During the trial, hooves were scored for DD lesions on a monthly basis using a disease severity score (A): from 0 = no lesion, up to 60 = ulcerative lesion ≥2.5 cm and categorically with 3 categories (B): 'none', 'non-active' and 'active'. Results A: Mean area under the curve of the numerical score that summarizes development over time was substantially and statistically significantly smaller in the treatment group. Results B: Two-step regression analysis for the outcome category at evaluation day (with exclusion of the first baseline evaluation) showed that during the trial, compared with the treatment group, odds of having a lesion rather than none was 4 times higher in the control group and the odds of having an active lesion compared with an inactive one were almost 6 times higher in the control group. Additionally, spraying had a statistically significant preventive effect for the feet of heifers (n = 17) introduced to the herd during the trial on farm 1: Only one active lesion occurred in the treatment group with numerous active lesions observed in the control group and mean area under the curve of the numerical score over time was statistically significantly lower in the treatment group, too. No active lesions occurred in heifers of farm 2 (n = 12) in either of the study groups. The iron, zinc and aluminum-based product effectively reduced disease prevalence and disease severity during the one-year study period in the examined dairy herds and data from heifers suggest that the application of the product to heifers 4 weeks before entering a herd with controlled DD management measures has high potential for prevention of the disease.

Development of a sustainable stabilized macadam road base using steel slag as supplementary cementitious material

As the main waste product of iron and steel industry, steel slag possesses considerable cementitious activity, making it a promising alternative to cement in Cement Stabilized Macadam (CSM). However, CSM was inevitably exposed to groundwater and rainwater when served as the pavement base course, leading to concerns over poor early strength and potential pollutant leakage, which are the main factors that may hinder the widespread utilization of steel slag in CSM base. To address these issues, this study investigated the feasibility of using steel slag powder to produce CSM. Steel Slag Powder-Cement Stabilized Macadam (SSCSM) samples were prepared and the hydration products, microstructure, mechanical properties, water damage resistance and heavy metal ions leaching behavior were investigated. The results show that the nucleation effect of steel slag powder accelerates the early hydration, but the C-S-H produced by hydration is not sufficient to form a stable hydration product network, so the microstructure of SSCSM is looser than that of CSM. The addition of steel slag powder improved the shrinkage performance of SSCSM, and the mechanical properties and heavy metal ion leaching concentration of SSCSM meet the engineering application requirements when the steel slag powder replacement level does not exceed 30 %. It was also found that the addition of steel slag powder promoted the development of pores in SSCSM samples after dry-wet cycles, resulting in the reduction of water damage resistance. Compared with conventional CSM, the use of SSCSM can not only reduce 4 % of raw material cost and 23.5 % of equivalent CO2 emission, but also mitigate the heavy metal ions leaching risk associated with steel slag, making it an effective and sustainable solution for steel slag recycling.