Metallurgical Technology Research Articles

A metallurgical technology investigation of the Wangxiangping ancient smelting sites at Daye County, Hubei Province

In the spring of 2022, the Beijing University of Science and Technology conducted an archaeometallurgical survey at the Wangxiangping site in Daye County. This exploratory excavation revealed pottery and metal smelting artifacts dating back to the Shang and Zhou dynasties. Charcoal samples from the third stratigraphic layer were carbon-dated to as early as the late Shang Dynasty. The SEM-EDS (Scanning Electron Microscopy-Energy Dispersive Spectroscopy) method was utilized for analyzing metallurgical artifacts across all stratigraphic layers at the site. The findings suggest that both pure copper smelting and tin bronze smelting activities were simultaneously conducted at this location. The analysis indicates that secondary copper oxide ore underwent reduction smelting, leading to the production of pure copper and high-grade matte. Additionally, tin ore was used in bronze production, with tin serving as an alloying element. However, no remnants from casting activities were identified during this survey. The investigation and subsequent analytical processes performed at this site provide substantial evidence supporting further research into copper smelting practices in Daye area during Shang and Zhou dynasties.

SIGNIFICANCE OF ASSESSMENT AND COMMUNICATION WITH THE TEACHER IN THE CHEMICAL TECHNOLOGY LEARNING PROCESS

SIGNIFICANCE OF ASSESSMENT AND COMMUNICATION WITH THE TEACHER IN THE CHEMICAL TECHNOLOGY LEARNING PROCESS

CONDITION BASED ASSESSMENT FOR PREDICTIVE MAINTENANCE OF METALLURGICAL EQUIPMENT

The continuous nature of metallurgical technologies and the intensification of production increase the risk of damage to high-temperature equipment during the technological process. The destruction of the structural integrity of the refractory insulation of this equipment leads to the forced interruption of production and significant costs of emergency response and require measures to be taken to reduce the risk of such situations. An opportunity to solve these problems in the metallurgical industry is the introduction into the production process of sustainable systems for making informed decisions and predictive maintenance of equipment, based on continuous or periodic monitoring of the condition of refractory insulation of high-temperature furnaces and auxiliary equipment.
 Predictive maintenance of technological equipment and aggregates, based on an assessment of their current condition, extends their life, reduces downtime, maintains the optimal level of production, and guarantees compliance with the exact delivery time of production (raw materials, materials, energy). A procedure is presented for assessing the real condition of steel ladles based on periodic monitoring results as part of a decision-making system for predictive and safe use of their maximum resource.

Évaluation de la pensée philosophique sur l’ancienne culture chinoise de la technologie métallurgique

Abstract: Ancient China’s metallurgical technology is known for its antiquity and delicacy, but, for a long time, people have always been sensitive to the philosophical ideas contained in it, lacking a rational understanding and theoretical generalization. Metallurgical technology is a typical technology in ancient Chinese craftsmanship. It provided a detailed analysis of the philosophical ideas contained in metallurgical technology, including ironmaking (steelmaking) technology and bronze smelting and casting technology. It is believed that the prominent features of ancient Chinese metallurgical technology culture are the emphasis on the importance of philosophy, the emphasis on “timing, geographical advantages, and human harmony”, and the emphasis on the philosophical thought of “harmony”.

The Low‐Carbon Production of Iron and Steel Industry Transition Process in China

Severe greenhouse gas emissions have made global warming one of humanity's most critical and intricate environmental challenges. As the world's largest producer and exporter of steel, China's steel industry contributes substantially to carbon emissions. The government formulated the policies and pathways to achieve carbon neutrality, and enterprises have proactively pursued low‐carbon technologies. In this review, the decarbonization process in the Chinese steel industry is classified into three stages according to the decarbonization amount and technological maturity: the improvements of the blast furnace‐basic oxygen furnace, the attempt of the nonblast furnace, and the preparatory electricity‐hydrogen coupling metallurgy. This article reviewed the industrial‐scale low‐carbon metallurgical technologies represented by the Baowu HyCORF process, bottom‐blowing O2‐CO2‐pulverized lime converter process, gas‐based direct reduction shaft furnace process, Molong HIsmelt process, and Ouye furnace process, as well as pointed out the development limitations of those processes. Additionally, the study presented prospects for zero‐carbon emission technologies coupling green energy generation and hydrogen metallurgy. These findings will offer substantial support for advancing research and development of low‐carbon metallurgical technologies and formulating relevant policies in the future.

Corrosion inhibition induced by captopril in Hanks’ solution on bioresorbable Mg–Zn-(Y, Nd) alloys fabricated by powder metallurgical technology

Mg–Zn alloys containing rare-earth elements (REEs) have been regarded as potential candidates for bioresorbable stent materials. As implanted in coronary arteries, stents could be exposed to angiotensin-converting enzyme (ACE) inhibitor drugs that are widely used for post-percutaneous coronary intervention patient therapy. This work investigates the inhibitory effect of an ACE inhibitor drug, namely captopril, on the corrosion behavior of Mg–Zn-(Y, Nd) alloys in Hanks' solution. Three alloy compositions, namely Mg–1Zn-2.9Y, Mg–5Zn-1Nd, and Mg–2Zn-0.2Y-0.5Nd, were prepared by a powder metallurgical (PM) method. The corrosion behavior and inhibition efficiency were studied using potentiodynamic polarization, electrochemical impedance spectroscopy (EIS), Mott-Schottky analysis, and a hydrogen evolution test. It is shown that captopril suppressed the dissolution kinetics of Mg–Zn-(Y, Nd) alloys in Hanks' solution. The captopril inhibition efficiencies (η) for the alloys are in the order of Mg–2Zn-0.2Y-0.5Nd > Mg–5Zn-1Nd > Mg–1Zn-2.9Y. A remarkable η of 48.4 % has been achieved for the Mg–2Zn-0.2Y-0.5Nd alloy. The EIS results revealed that the polarization resistance increased in the alloys after the addition of captopril to Hanks' solution. The Mott-Schottky analysis showed that the Mg–Zn-(Y, Nd) alloys behaved as an n-type semiconductor but switched to a p-type for the Mg–1Zn-2.9Y alloy in the captopril-containing Hanks’ solution. The surface analysis of the post-corrosion-tested sample has observed captopril film partially covering the α-Mg matrix, which acted as a protective layer against corrosion.

Kinetics analysis of direct reduction of iron ore by hydrogen in fluidized bed based on response surface methodology

The present research investigates the efficacy of fluidized bed direct reduction of hematite ore using H2 as a metallurgical technology. The study uses response surface methodology (RSM) to obtain the optimal kinetics system for fluidized H2 reduction of hematite ore. The interaction of independent parameters, including reduction time, reduction temperature, fluidizing velocity, and H2 concentration with dependent variables comprising the reduction degree are explored. The final equation for the reduction degree can be established according to RSM analysis. Additionally, for the hematite reduction using H2 in a fluidized, the study investigates the mechanisms and kinetics of isothermal reduction. The result demonstrates that the reduction degree increases with the reduction temperature, fluidizing velocity, and H2 concentration, as well as the reduction mechanisms change with reduction conditions. For instance, an increase in fluidizing velocity and H2 content promotes the transformation of the kinetics model from D3 to D3+F1 and R3+F1 mixed control, respectively. The activation energy for the fluidized H2 reduction of hematite ore to metallic iron Fe ranges from 23.76 to 54.89 kJ/mol.

Microscale iron spherules as a trace of metallurgical activity in Old-Polish Industrial District river valleys

Abstract In the last few centuries, a metallurgical industry based on forges driven by water wheels developed in many European valleys. One such area is the Old-Polish Industrial District (OPID) in Central Poland, which is one of the largest of this type of industrial center. Metallurgical activity developed here from the Prehistoric to modern times. The transformation of metallurgical technology led to the collapse of production, and the ongoing renaturation obliterated most of the traces of former industrial activity. The Magnetic Spherule Separation method used so far in Western Europe, and recently in Poland, has been able to detect traces of former metallurgical activity preserved in alluvium. Fluvial deposits contain microscopic, perfectly spherical iron hammerscales formed during metallurgical production. The results of the study of the alluvium of selected rivers in the OPID indicate the presence of iron spherules of various origin and facies in the sediments of the floodplain, which accumulated during the period of metallurgical activity and were redeposited in modern times. This allows us to estimate, among other things, the age, rate of accumulation and impact of anthropopressure on sedimentation conditions.

Contribution of mineral processing and metallurgical technology to sustainable development of world mining industry

Contribution of mineral processing and metallurgical technology to sustainable development of world mining industry

The effect of chemical variability and weathering on Raman spectra of enargite and fahlore

Abstract. Enargite (Cu3AsS4) and tennantite (Cu12As4S13) are typical As-bearing sulfides in intermediate- and high-sulfidation epithermal deposits. Trace and major element variations in enargite and tennantite and their substitution mechanisms are widely described. However, Raman spectra of the minerals with correlative quantitative chemical information are rarely documented, especially for enargite. Therefore, comparative electron and μ-Raman microprobe analyses were performed on enargite and fahlore grains. These spectra can be used in the industrial detection and subsequent removal of As-bearing sulfides prior to ore beneficiation in order to diminish the environmental impact of the metallurgical technologies. A simple Sb5+–As5+ substitution in enargite was confirmed by Raman analyses. Similarly, a complete solid solution series from tetrahedrite to tennantite (i.e., Sb3+–As3+ substitution) can be correlated with a gradual evolution in their Raman spectra. In turn, Te4+ occupies the As3+ and Sb3+ sites in fahlore by the coupled substitution Te4+ + Cu+ → (As, Sb)3+ + (Cu, Fe, Zn)2+. Accordingly, Raman bands of goldfieldite (Te-rich member) are strongly broadened compared with those of tetrahedrite and tennantite. A secondary phase with high porosity and a fibrous or wormlike texture was found in enargite in a weathered sample. The chemical composition, Raman spectrum, and X-ray diffraction signature of the secondary phase resemble tennantite. A gradual transformation of the primary enargite into this secondary phase was visualized by comparative electron and Raman microprobe mapping.

A new piece of the puzzle: slag and ore analysis to reconstruct the prehispanic smelting technology at the Atacama Desert, Chile

The Incas appropriated many local metallurgical technologies throughout the Andes, each of which had its unique peculiarities and was based on local ancestral knowledge. The widespread use of tin-bronze during the Inca expansion, the development of mining and smelting sites, as well as ethno-historical records evidence the Incas’ interest in copper smelting, a key activity in the Andes since ca. 1400 BC. However, little is known about the technical parameters achieved by ancient metallurgists and the changes that occurred during the Inca expansion. In this paper, we address these changes through a case study of Copiapó valley, focusing on the Viña del Cerro site, one of the most famous Inca smelting centres of the southern Andes. Although this place was architectonically restructured by the Incas, its operations began long before the imperial expansion and used wind-powered furnaces. We analysed 19 slag and 11 copper ore samples using OM, SEM–EDS, WD-XRF, and XRD analyses. Results identified heterogeneous and viscous slags, rich in SiO2 (43 wt%) and poor in FeO (13 wt%). Copper retention was high (up to 60 wt%). Microstructural analyses indicate that slags were formed under unstable oxidising conditions, reaching temperatures that ranged between 1000 to 1100 °C. The copper produced was very pure. High-grade copper ores containing up to 69 wt% CuO were reduced at the site, combining carbonates (malachite, azurite), halides (buttgenbachite, clinoatacamite), and some sulphates (brochantite). We propose that even under the relatively unfavourable conditions for slag formation, the smelting conditions generated at Viña del Cerro were competent enough to extract metal, but not necessarily enough to form liquid slag. These conditions were facilitated by the local metallurgists’ thorough knowledge of the wind flow and their ability to select the right ore. This new information contributes to understanding the efficiency of metallurgical technology and the knowledge, skills, and adaptability of the ancient metallurgists from Copiapó valley, a group that was integrated into the economic networks of the Inca Empire.

Numerical simulation study on the effects of co-injection of pulverized coal and SPL (Spent Pot-Lining) into the blast furnace

This study investigated the potential use of spent pot-lining (SPL) as a supplementary fuel in blast furnaces (BFs) to replace coke or pulverized coal (PC). A numerical model was established to study the combustion behavior of mixed fuel (MF) containing 80 % PC and 20 % SPL in the raceway of BF. The study focused on the effects of blast velocity, temperature, injection rate, and oxygen content on combustion. Results showed that the burnout rate has a positive relationship with blast velocity and oxygen content, and decreases with the increase of blast temperature and injection volume. To obtain a high temperature zone, it is recommended to increase the oxygen content and air volume of the blast, and the blast temperature (1473 K) and injection volume (169 kg/t) maintain the basic operating conditions. These results can provide insights into the potential use of SPL as a waste resource in iron-making processes, which can promote the substitution of industrial waste SPL for PC in high-energy-consuming industries, contribute to the development of green metallurgical technology, and advance global energy conservation and emission reduction techniques.

TRADITIONAL GOLD MINING IN AKYEM ABUAKWA IN GHANA’S EASTERN REGION

This study examines precolonial gold mining in Akyem Abuakwa in Ghana's Eastern Region. It uses a historiographical approach, combining primary and secondary data and oral interviews to show the mineral processing and metallurgical technology used in mining Abuakwa gold in the historic period. It also demonstrates that precolonial gold mining in Akyem Abuakwa was less destructive to the environment, compared to the modern mining. It also highlights the techniques utilised by native Africans to mine gold, before the advent of Western technology and finance.

Self-Assembly and Properties of Elastic Nanocellulose-Carbon Airgel with Ordered Porosity by Template-Free Directional Freezing

Porous cellulose aerogels with different compositions have been fabricated via three methods, including regular freezing, directional freezing, and hydrothermal treatment, using pure cellulose oxide and cellulose oxide/graphite oxide composites, respectively. The cellulose aerogels are highly elastic and light in weight. The carbon aerogels show an ordered structure through directional freezing with layered skeleton bones and some folds. Unlike low-temperature freezing, the structures can obtain elastic properties. When the deformation is 20%, carbon aerogels can rebound to 95% of their original volume. The cellulose oxide/graphite oxide composite aerogels are synthesized into carbon–aerogel composites, which also have stable and robust structures of bone skeletons due to nanosheets. The carbon–aerogel composites have more than 85% resilience under 40% deformations. Carbon aerogels prepared from nanocelluloses have a novel three-dimensional network structure and have the application of elasticity, which is expected to be applied to metallurgical technology and the aerospace field. Through directional freezing, the carbon aerogels have regular structures of layered skeleton bones with some folds. In contrast to low-temperature freezing, the structures possess excellent elastic properties.

Assessing the iron-working skills at Roman Iudaea: An archaeometallurgical study of two Bar-Kokhba revolt assemblages from Israel

Studies of Roman metallurgical technology in the Eastern Mediterranean region have been rarely published. Despite many excavations and ferrous finds, this absence is also attested at the Roman province of Iudaea. In order to further our understanding of this craft at Roman Iudaea, twelve artifacts from two adjacent sites, Horvat Tsalit and the Nahal Yattir Site, were sampled for a metallographic study, applying both optical and electron microscopy. Dating to the late 1st – early 2nd cen. CE, both sites were Jewish villages destroyed by the Roman army during the Bar-Kokhba revolt. The assemblage includes Roman arms, local agricultural tools, and non-utilitarian artifacts. Despite the corroded samples, examining a range of artifact functions has allowed us to identify that low-carbon steel semi-products were typically used. Smiths provided these with mechanical properties requisite to different functions by hardening techniques such as forge-welding steels of varying C content and cold-working. On the other hand, some objects were intentionally made to be malleable. We hope that a growing body of comparable studies from the region will allow us to gain further insights into local smithing traditions and the relation between artifact type, function, and technology.

Formation of Twin Boundaries in Rapidly Solidified Metals through Deformation Twinning.

The rapid solidification process is relevant to many emerging metallurgical technologies. Compared with conventional solidification processes, high-density microstructure defects and residual thermal stress are commonly seen in rapidly solidified metals. Among the various defects, potentially beneficial twin boundaries have been observed in the rapidly solidified nanocrystalline microstructures of many alloy systems. In this work, a pathway for forming twin boundaries in rapid solidification processes is proposed. A detailed derivation of strain inhomogeneities upon thermal shrinkage and the deformation twinning phase field method is given. By calculating cooling-induced thermal strain inhomogeneity in nanocrystalline metals and growth thresholds for deformation twinning using the phase field method, it is shown that residual thermal strain hotspots in the microstructure can reach the threshold for deformation twinning when the shear elastic property of grain boundaries is significantly different from the bulk.

The Current Situation, Development, and Prospects of the Iron and Steel Industry in the Process towards the “Dual Carbon” Goals

The iron and steel industry is the largest carbon emitter in China’s manufacturing sector and one of the most important fields in the country’s response to climate change. This paper aims to explain the current situation, technological pathways, and future direction of green and low-carbon development of the iron and steel industry. According to the carbon emissions of the iron and steel industry, this paper analyzes the relationship between steelmaking technologies and carbon emissions, as well as the transformation trend of the world’s iron and steel industry, finding that China’s iron and steel industry faces both opportunities and challenges. Steel scrap recycling and electric furnace steelmaking technologies, re-electrification, hydrogen metallurgy, resource recycling and by-products, and carbon capture and utilization (CCU) are the main technologies tailored to the transformation pathways, and the optimization of energy consumption structure is an important direction for future development. Therefore, this paper believes that clean energy, as a guarantee for carbon mitigation, will play an increasingly important role in the process towards achieving carbon peaking and carbon neutrality goals (the “dual carbon” goals), in addition to the transformation of metallurgical technologies.

In-Pit Disposal of Mine Tailings for a Sustainable Mine Closure: A Responsible Alternative to Develop Long-Term Green Mining Solutions

In the next decades many of the old tailings storage facilities (TSFs) could be re-processed if one considers the prices of metals, new uses of metals which today are not valuable, and the application of new, more efficient metallurgical technologies. In this context, in-pit disposal of mine tailings (IPDMT) is an attractive alternative to be used as part of responsible mine closure: mines could reprocess the mine tailings and place them in an open pit as part of sustainable mine closure. This article explores a little-explored tailings disposal technique that has the potential to be considered as an environmentally friendly solution, returning mine tailings to their place of origin and providing long-term stability under a climate change scenario. This article presents the main features, benefits, and potential drawbacks of IPDMT, with an emphasis on: (i) a description of the main advantages and disadvantages of application; and design issues related to (ii) IPDMT physical stability (pit slope stability, tailings transport, placement systems); (iii) IPDMT hydrological stability (water management, seepage control, hydrogeological monitoring,); and (iv) IPDMT geochemical stability (geochemical characterization, acid rock drainage control, covers). The novelty of this article is the proposal to change the status quo of traditional management of mine tailings to a new paradigm where the technique of in-pit disposal of mine tailings can be considered a green mining solution for mine closure. Finally, some successful cases around the world that involved the implementation of this technique are presented.

Origin and Evolution of the Earliest Iron-Smelting Technologies in the Khakass-Minusinsk Basin

The Khakass-Minusinsk Basin is archaeologically one of the best studied regions of Russia. Bronze artifacts from the pre-Scythian and Scythian epoch from that area are famous worldwide. However, iron production appears rather late there. From 2009 to 2018, a joint Russian-Japanese expedition excavated several sites documenting the earliest iron manufacture in the Khakass-Minusinsk Basin. On the basis of these excavations and experiments, metallurgical technology was reconstructed. The results suggest an evolutionary model of metal production in the Khakass-Minusinsk Basin during the Xiongnu-Sarmatian period. Three types of iron-smelting furnaces are described, structurally differing in terms of air-blasting and slag removal. The conclusion is made that the initial iron production technology had been borrowed, and later evolved in situ.

Powder Metallurgy: A New Path for Advanced Titanium Alloys in the EU Medical Device Supply Chain

New beta titanium alloys are expected to present high mechanical properties with good biocompatibility to meet the demands of next-generation implants. This paper presents an overview of the current European Union titanium supply chain and several metallurgical processes and technologies required to develop the beta-based titanium alloy industry. The thermomechanical process involves manufacturing advanced beta titanium alloys, where cost reduction must involve every step of the entire process. When synergistically combined, powder metallurgical technology, together with a set metallurgical process, can produce advanced materials for the biomedical industry with a low-cost ratio compared to current melting and forging manufacturing routes. We propose a new strategy to increase the role of advanced titanium alloys in the European Union medical device supply chain.