Metal Products Research Articles

ANTI-CORROSION COATING BASED ON PRODUCTION AND CONSUMPTION WASTE

The process of corrosive decay of metal products leads to serious consequences both for the products themselves and for the quality of the environment, therefore protection against corrosion is carried out by isolating structures from an aggressive environment using various protective coatings. One of the promising directions in the sphere of corrosion protection is the production of such coatings based on waste with anti-corrosion potential (galvanic sludge, used motor oil), which is thesubject of this article. On the basis of the analysis of chemical composition and physicochemi-cal characteristics of the considered wastes the possibility of their use for obtaining effective anti-corrosion coating is proved. The realization of the proposed technology makes it possible to solve a number of topical issues of important social and economic importance, namely the problem of the accumulation of hazardous waste and the preservation of the general metal stock.

Environmental Assessment/Evaluation of 3D Printing and 3D Printing with Wood-PLA Composites - Case Study

In recent years, additive manufacturing has become a regular process in various industries, and consequently there is an increasing need to evaluate the environmental aspects of this technology and its associated materials. In this paper, comparative cradle-to-grave life cycle assessments between a conventional product and a 3D-printed alternative made of polylactic acid (PLA) and PLA-wood material were investigated based on the standard ISO 14044:2006. The environmental impact of each product was quantified for 18 categories. The goal of life cycle assessment (LCA) was to determine whether the use of 3D printed PLA/PLA-wood products can be a sustainable alternative to traditional metal products. The paper presents a case study in which a comparative LCA was conducted. The results show that a metal part manufactured using conventional subtractive processes (milling, drilling, welding, etc.) has a higher environmental impact compared to 3D-printed alternatives made from renewable materials. However, there are many sub-issues that need to be adequately addressed.

Enamel materials and its relation with jewellery and metal products field

Enamel materials and its relation with jewellery and metal products field

Electrolysis in Chloride Molten Salts for Sustainable Critical Metals Production and Recovery

Critical materials, such as rare-earth metals, are essential to numerous applications, including clean energy; however, the present industrial practices for producing rare-earth metals involve environmentally damaging and thus unsustainable chemical and electrochemical processes. An alternative moderate-temperature chloride-based molten salt electrolysis process can address these issues, providing energy efficient and sustainable metal production. While it is being developed presently for rare-earth electrowinning, one can easily envision its broader application to rare-earth electrorefining and the electrolytic production of high-volume metals like Fe and Al. Presently, these high-volume metals industries account for nearly 10% of global greenhouse gas emissions. Thus, the chloride MSE process presents a huge opportunity for truly achieving sustainability if it is developed further for producing Fe, Al, Ti, Mg, and other commodity metals.

Solidification behavior and continuous preparation process of high-quality Zr-based metallic glass plates based on twin-roll strip casting

Metallic glasses exhibit excellent comprehensive properties in a variety of disciplines including mechanics, magnetism, electricity, and chemistry, making them highly promising for various applications. However, the current lack of continuous and efficient preparation technology for metallic glasses not only hinders the research and application of various metallic glass products but also contributes to the high cost associated with their production. In this study, we incorporate the twin-roll strip casting technology into the continuous fabrication process of metallic glass plates. By conducting numerical simulations and practical experiments, we elucidated the solidification process of metallic glasses in the twin-roll strip casting process. A process control strategy was developed focusing on "small molten pool height and low exit temperature", which enabled successful preparation of high-quality Zr55Cu30Al10Ni5 metallic glass plates ranging from 0.13 to 0.56 mm in thickness. A reduced pool height can enhance the cooling rate of metallic glasses and suppress the formation of vortices and crystals within the molten pool. By employing a lower exit temperature, it is possible to achieve a metallic glass plate characterized by high-energy microstructure, exceptional mechanical properties, as well as superior shape and surface quality. This research provides valuable guidance for continuous production of superior-grade metallic glass plates using twin-roll strip casting technique.

Lunar simulant behaviour in molten fluoride salt for ISRU applications

This study investigated the behaviour of a lunar mare crystalline analog dissolved in molten LiF–NaF at 800 °C for the in situ production of metals as a part of In Situ Resource Utilization (ISRU) research. Molten fluorides have the capability to dissolve metallic oxides, and the Hall-Héroult process uses this kind of media to produce Al from Al2O3.The first step was to compare the individual solubility of the main oxides composing the mare lunar soil (SiO2, Al2O3, Fe2O3, and MgO) with the solubility of the crystalline analog using Inductively Coupled Plasma – Atomic Emission Spectroscopy (ICP-AES). The species concentration added jointly are lower than the concentration of the same species added separately. Nonetheless, this study showed that LiF–NaF can be used to dissolve the analog with a maximum solubility of 3.9 wt% at 800 °C. Cyclic voltammograms were also used to verify the electroactivity of all oxide species in LiF–NaF, wherein all the main oxides are electroactive except SiO2 and TiO2. Then electrolyses on different cathodic substrates were performed at different conditions and the obtained cathodic products were analysed with a scanning electron microscope (SEM) coupled with an energy dispersive spectroscopy (EDS). Despite the non-electroactivity of SiO2 and TiO2, they were extracted in an alloyed form through Under Potential Deposition (UPD). Metallic deposition of other metals such as aluminium and titanium was achieved on carbon electrode. Finally, a synthetic mixture made of the different oxide species with the same chemical composition as the simulant, was investigated as a viable substitute for lunar mare soil. Its electrochemical behaviour was identical to the crystalline lunar simulant showing that our original process based on oxides dissolution is not influenced by the amorphous/crystalline state of the raw material.the outputs of LiF–NaF molten process are not critically influenced by the physical state of the lunar regolith.

About Some Properties of Structural Steel Used in the Construction of a Railway Bridge Over the Amur River in the Early XX Century

The main stages of construction in 1913–1916 of the railroad bridge across the Amur River near Khabarovsk are presented. The peculiarities of the construction of the structure in the difficult foreign policy conditions of the beginning of the last century, which caused a reduction in the pace of construction, are noted. The most honored organizers, designers and builders of the Amur Bridge are mentioned. Construction materials and places of their extraction, as well as suppliers of structural steel used in the construction of a unique transportation structure are specified. The methods of construction and assembly of the main load-bearing elements of the bridge structure are considered. Special attention is paid to the study of chemical composition, micro- and macrostructure, hardness of structural steels used in the manufacture of bridge spans. Conclusions about the conformity of the chemical composition of the investigated materials to the alloys specified in the current normative documentation, as well as the method of their smelting are formed. Modern metal materials used in the reconstruction of the bridge crossing at the beginning of the XXI century are given for comparison. The functionality of the bridge after reconstruction is reflected and the potential of its further development is given. A promising method of increasing the complex of characteristics of metal products by processing billets in solid-liquid state, which allows to reduce the metal consumption of structures, is considered.

Analysis of Resource Efficiency Management Indices through Industry Material Flow Analysis: Focusing on Manufacture of Fabricated Metal Products Industry

Analysis of Resource Efficiency Management Indices through Industry Material Flow Analysis: Focusing on Manufacture of Fabricated Metal Products Industry

Separation of Li and Co From LiCoO2 Cathode Material Through Aluminothermic Reduction: Investigation of the Thermite Reaction

Aluminum can be used as a reductant for metal oxide reduction processes. This study investigates the reaction between Al with LiCoO2 in the context of recycling and separation of Li and Co from end-of-life battery cathode material. Specifically, this work attempts to investigate the initiation of the ignition of the thermite reaction. Both thermodynamic assessments and experimental work were carried out on the LiCoO2-Al system in the range of 750 °C to 1020 °C with three different amounts of Al additions in the sample, i.e., 11 wt pct, 20 wt pct, and 28 wt pct. It was found that the amount of Al (composition of the sample), the sample weight, and the initial heating temperature affect the occurrence of spontaneous ignition of the thermite reaction in the system leading to the partial/full melting of the sample. A function of Biot number and temperature was utilized to construct maps showing the onset of ignition where it was found that samples with large Biot numbers tend to ignite. In addition, higher Al addition, sample mass, and temperature were likely to generate ignition. The ignition was found to govern the type of end products of Li and Co; for example, the Li was distributed to gas as Li(g) and slag as LiAlO2 while Co could be extracted as Co metal or Co-Al alloy. The 11 wt pct and 20 wt pct Al addition to the samples resulted in a pure metallic cobalt product, whereas 28 wt pct Al addition resulted in CoAl alloy with a composition of 86.1 wt pct Co and 13.9 wt pct Al. The final product of the vaporized Li was in the form of Li(OH) due to the exposure to water vapor in the atmosphere upon collection. This aluminothermic approach is considered as a promising method to recover Li and Co from waste LiCoO2.

Lead isotopes of prehistoric copper tools define metallurgical phases in Late Neolithic and Eneolithic Italy.

The diffuse presence of small copper ore deposits in the Alpine area, mostly exploited since Late Medieval times, led most scholars to assume that these deposits may actually be active much earlier and that many of the circulating prehistoric metal objects found in the area were produced with local copper sources. This assumption was recently validated for the Recent Bronze Age through the use of lead isotope tracers, and well supported by the archaeometallurgical evidences found in the South-Eastern Alps. However, the scarcity of available lead isotope data for pre-Bronze Age metals precluded to date the reconstruction of the metal flow through the Late Neolithic and Eneolithic (or Copper Age). Based on 49 new analyses of important archaeological objects from the Alpine region, the Po River Valley and Central Italy, mostly axes dated from the Late Neolithic to the Late Eneolithic, here we show that the diffusion of copper in Northern Italy (approximately 4500-2200 BC) includes three major periods of metal use and/or production, each related to specific ore sources. The South Alpine copper was massively used only starting from the middle of the 3rd millennium BC, in connection or slightly earlier than the Beaker event.

Distribution of Iron and Boron Between Silicon Metal Smelting Products in Industrial Saf using Borate Fluxes

The article identifies the key sources of iron and boron impurities entering silicon metal under industrial smelting conditions in Submerged arc furnace (SAF). Impurity rocks in the composition of quartz, the main raw material for the production of silicon metal, were studied using the X-ray fluorescence method, and their visual classification was carried out. It has been established that the energy of secondary characteristic x-ray radiation (CXR) for boron and iron contained in the feedstock is 3.1 and 6.3 keV, respectively. A relationship was found between the intensity of CXR pulses and the concentration of iron and boron impurities. The features of the distribution of these elements between metallurgical phases (silicon metal, slag and gas phase) when used in the smelting process with and without borate flux (colemanite) have been established. Under industrial conditions, it has been established that the transfer coefficient of boron into silicon metal is reduced when using borate flux from 76.3% to 58.36%. The transfer of iron into silicon metal from the charge remains at the same level with a slight downward trend from 93.18% to 92.12%. This may be explained by a reduction in the contact time of the molten slag accumulating on the bottom with liquid silicon metal. There is also a reduction in the consumption of charge materials when using colemanite from 6.07 to 5.635 t/t of silicon metal due to the reduction in the time of cleaning the smelting bath from viscous slag accumulated on the bottom.

Continuous light-guide control of melts temperature in induction furnaces

The article is devoted to the question of the most effective for the full use of the induction furnaces technological flexibility continuous temperature control. The aim of the work is to create a light-guide technology for continuous temperature control of the processes of induction melting, treatment and pouring of liquid metal in metallurgy of machine building. The investigations of crucible and channel, melting, holding and pouring induction furnaces from the standpoint of light-guide thermometry have been developed. Materials, designs, as well as technologies of manufacturing, mounting and safe operation of the light-guide and auxiliary devices have also been investigated. Using the results of complex studies, the base light-guide thermometry system, general and particular methods of the light-guide temperature measurements have been developed. On the base of the Huygens construction, as well as the laws of geometric and crystal optics, techniques for calculation of the optical characteristics of the light-guide and focusing devices, as well as schemes of their optical joint have been developed. These techniques increase the metrological characteristics of the light-guide thermometry. Standard construction of the secondary part of thermometry system requires classical pyrometry methods application. These methods are acceptable for continuously operated metallurgical aggregates, where stable emissivity of the light-guide operating end takes place. The secondary part of thermometry system has been modernized in order to widen application field of light-guide thermometry on periodically operated metallurgical aggregates where emissivity of light-guide immersion end randomly changes. Modernized secondary part is purposed for spectral (multicolor) pyrometry methods realization. These methods minimize influence of the instability of emissivity of light-guide immersion end on methodical errors of temperature measurements. Research and industrial exploitation, at domestic and foreign enterprises, have shown obvious metrological advantages of the light-guide thermometry technology in comparison with known solutions. Implementation of the light-guide thermometry systems on induction furnaces has high technical-economic efficiency, including by reduction the spoilage of metal products and resource costs for production. Keywords: induction furnace, continuous temperature control, light-guide thermometry, amorphous, poly- and single-crystalline materials, measurement error, Huygens construction, technical-economic efficiency.

Potential toxic heavy metals in village rainwater runoff of antimony mining area, China: Distribution, pollution sources, and risk assessment

The potential toxic heavy metal runoff from antimony mining areas poses a serious threat to the water environment and the health of residents in the village. The study found that the average concentrations of As, Sb, Cr, Pb, and Cd in the runoff were 0.1237, 0.1148, 0.0332, 0.0140, and 0.0013 mg/L, which were higher than the normal average concentrations in the water environment of 0.018, 0.0009, 0.05, 0.012, and 0.000013 mg/L, respectively.Sb and As are severely polluted, while Cd, Pb, and Cr have lower pollution levels. The coefficients of variation for As, Sb, Cr, Pb, and Cd range from 0.079 to 1.051, with Sb showing exceptionally high variability. Heavy metal elements Pb, Cd, and Sb accumulate in the southeastern area of the village, with Sb concentrations decreasing from the southeast to the northwest. As is mainly distributed in the northeastern part of the village, while Cr is primarily found in the central-western region. Source analysis indicates that As and Sb originate from mining and industrial activities, dust deposition, and domestic sewage. Cr comes from the natural geological background and metal product industry, Pb from lead-acid batteries, industrial activities, and gasoline additives, and Cd from fertilization in residential green areas and pesticide use. Health risk analysis reveals that the hazard index (HI) values for As and As in the water environment are 1.49 and 2.31, respectively, both exceeding 1, posing a serious threat to the health of village residents. The HI values for Pb, Cr, and Cd elements are all below 1, indicating lower risks. This study identified that Sb in the antimony ore area and its associated metal element As are the main elements leading to potential heavy metal pollution in the runoff of village residential areas, providing direction for subsequent water environment restoration work.

Digital maturity of the Russian metallurgical industry: drivers and challenges of growth in new geopolitical conditions. Part II. Key directions of digital transformation

The article continues the research on the prospects of achieving digital maturity in Russian metallurgical industry as one of the digitalization drivers of the Russian economy. The analysis results showed that the metallurgical business has a high innovative potential for the digital maturity growth. The second part examines the application of Industry 4.0 technologies in domestic metallurgy by the example of industry leaders in digitalization. The purpose study is to determine the directions of digital transformation in metallurgy to achieve digital maturity in new geopolitical conditions based on the innovative activity assessment of industry leaders. The study object is Russian metallurgical companies (technological development of the industry) drivers. The study subject is the digital transformation process of metallurgical companies in the conditions of economic sanctions. The research methodology is based on the innovation activity assessment. The research methods include indicative, comparative, and statistical analyses. The impact of the economic sanctions imposed in 2022 on the digital transformation in the industry has been assessed, problems and approaches to their solution have been identified. The study results demonstrated the significant potential of the metallurgical industry to achieve digital maturity due to the high innovative activity of industry leaders, despite the sanctions. The key areas of digital transformation are digital twins, machine vision and artificial intelligence, the creation of metal products and secondary raw materials marketplaces, which corresponds to the global digitalization trend. This paper is a continuation of the article “The digital maturity of the Russian metallurgical industry: drivers and growth challenges in the new geopolitical environment. Part I. Assessment of the innovation potential of digital transformation”.

Assessment of cross-sectoral relations of Polish mechanical engineering

As a result of the conducted research, it was found that the sectors of Polish mechanical engineering are not sufficiently interconnected. This is determined and caused by the insufficient level of technology, innovation, machine-building products, and the predominance of assembly plants. At the same time, on the other hand, the revealed interconnections of Polish mechanical engineering reflect those sectors in which significant business activity takes place in Poland. This is explained by the fact that in modern business conditions without the use of the necessary tools, devices, vehicles, it is difficult to achieve significant economic results. Therefore, the sectors that consume the most machine-building products can be considered the basic centers of the Polish economy. According to the obtained analytical results, agriculture, production of food products, rubber and plastic, metal products, all machine-building industries, energy sector, construction, trade sector, sphere of transport, telecommunications, information technologies, etc. can be attributed to them.

Study on carbon emission reduction countermeasures based on carbon emission influencing factors and trends.

The carbon mitigation response encompasses a variety of strategies aimed at mitigating greenhouse gas emissions resulting from human activities. These measures are crafted to address the challenges posed by climate change and facilitate the transition of businesses towards a low-carbon paradigm. Leveraging the analytical outcomes of the extended STIRPAT model and the PSO-BP prediction model, this paper suggests countermeasures for reducing carbon emissions in China's metal smelting industry. The overarching objective is to contribute to China's attainment of the "dual carbon objectives." The study identifies key factors influencing carbon emissions in the metal smelting industry, ranked in descending order of sensitivity: population, coal consumption, urbanization rate, total metal production, carbon intensity, proportion of secondary industry, and GDP per capita. Results from three established scenarios-namely, low carbon, standard, and high carbon-indicate a consistent decline in carbon emissions from China's metal smelting industry over the next 15 years. This research not only enhances the findings of existing studies on carbon emissions in the metal smelting sector but also introduces an innovative approach to carbon emission reduction within China's metal smelting industry.

Integrated Stochastic Underground Mine Planning with Long-Term Stockpiling: Method and Impacts of Using High-Order Sequential Simulations

The integrated optimization of stope design and underground mine production scheduling is an approach that has been shown to effectively leverage the synergies among these two underground mine planning components to generate truly optimal stope layouts and extraction sequences. The existing stochastic integrated methods, however, do not include several elements of a mining complex, such as stockpiles, due to the computational complexity and non-linearity that they might add to the optimization of the long-term mine plan. Additionally, sequential simulation methods that rely on two-point statistics and Gaussian distribution assumptions are commonly used to generate the input realizations of the mineral deposit. These methods, however, are not able to properly characterize complex spatial geometries or the high-grade connectivity of non-Gaussian and non-linear natural phenomena. The present work proposes an extension of previous developments on the integrated stope design and underground mine scheduling optimization through an expanded stochastic integer programming formulation that incorporates long-term stockpiling decisions. An application of the proposed method at an operating underground copper mine compares the cases in which the geological simulated orebody models are based on high-order and Gaussian sequential simulation methods. The extraction sequence and related final stope design are shown to be physically different. It is seen that the optimization process takes advantage of the better representation of high-grade connectivity when high-order sequential simulations are used, by targeting the areas with grades that follow the mill’s blending requirements and by making less use of the stockpiles. Overall, a 4% higher copper metal production and a resultant 6% higher net present value are observed when high-order sequential simulations are used.

Investigating Pre-Columbian Gold and Copper in Costa Rica – Ores, Mines and Artefact Production

The wealth of pre-Columbian gold, copper and guanín (an alloy consisting mainly of gold and copper; also tumbaga) artwork of Costa Rica suggests that exploitation of its abundant ore deposits goes back way before the Spanish conquest. The name of Costa Rica itself in fact alludes to the large numbers of golden metal objects worn by the indigenous peoples upon arrival of the conquistadors. Up to now, however, very little is known about pre-Columbian mining in the country or the raw material provenance of these artefacts.In a transdisciplinary project, we aim to reconstruct the metallurgical process chain by combining (mining) archaeological research with geochemical analysis of local ores and metal artefacts using a combination of different techniques. We identified four major gold and copper districts with different mineralisation types, which are the focus of our fieldwork-based research. They are surveyed for potential signs of pre-Columbian metal production and sampled for ores and their processing remains. On the other side of the process chain, we focus on the metal artefacts in museum collections. They are systematically registered in a database, which serves as a basis to identify correlations with the geochemical signatures of the artefacts, and to retrace potential links to possible areas of origin or different workshops. Once the necessary basic data have been collected, we will focus on economic and socio-cultural aspects of metal production and circulation. The results from Costa Rica will be put into perspective of New World early metallurgy and can provide a starting point for future research between Mesoamerica and the Isthmo-Colombian region.

Unleashing the power of AI in detecting metal surface defects: an optimized YOLOv7-tiny model approach.

The detection of surface defects on metal products during the production process is crucial for ensuring high-quality products. These defects also lead to significant losses in the high-tech industry. To address the issues of slow detection speed and low accuracy in traditional metal surface defect detection, an improved algorithm based on the YOLOv7-tiny model is proposed. Firstly, to enhance the feature extraction and fusion capabilities of the model, the depth aware convolution module (DAC) is introduced to replace all ELAN-T modules in the network. Secondly, the AWFP-Add module is added after the Concat module in the network's Head section to strengthen the network's ability to adaptively distinguish the importance of different features. Finally, in order to expedite model convergence and alleviate the problem of imbalanced positive and negative samples in the study, a new loss function called Focal-SIoU is used to replace the original model's CIoU loss function. To validate the effectiveness of the proposed model, two industrial metal surface defect datasets, GC10-DET and NEU-DET, were employed in our experiments. Experimental results demonstrate that the improved algorithm achieved detection frame rates exceeding 100 fps on both datasets. Furthermore, the enhanced model achieved an mAP of 81% on the GC10-DET dataset and 80.1% on the NEU-DET dataset. Compared to the original YOLOv7-tiny algorithm, this represents an increase in mAP of nearly 11% and 9.2%, respectively. Moreover, when compared to other novel algorithms, our improved model demonstrated enhanced detection accuracy and significantly improved detection speed. These results collectively indicate that our proposed enhanced model effectively fulfills the industry's demand for rapid and efficient detection and recognition of metal surface defects.

Controlling Crystal Growth of a Rare Earth Element Scandium Salt in Antisolvent Crystallization

Recovering scandium from hydrometallurgical residue bears the potential of a better supply of an industry depending on imports from countries with more mineral resources than Europe. To recover scandium from unused metal production residue, strip liquors from a solvent extraction process are treated with an antisolvent to crystallize the ammonium scandium fluoride salt (NH4)3ScF6 with high product yields. However, high local supersaturation leads to strong nucleation, resulting in small crystals, which are difficult to handle in the subsequent solid-liquid separation. Reducing local supersaturation makes it possible to reduce nucleation and control crystal growth. Key operation parameters are the concentration of ethanol in the feed and its addition rate. The concentration of the antisolvent in the feed causes a shorter mixing time in the proximity of the antisolvent inlet, which leads to a smaller local supersaturation and therefore less nucleation and more crystal growth. Lowering the antisolvent addition rate enhances this effect. The crystal size distribution during and at the end of the fed-batch process is analyzed by SEM imagery of sampled and dried crystals. To produce reproducible crystal size distribution from SEM images the neural network Mask R-CNN has been trained for the automated crystal detection and size analysis.