Hasil untuk "Mineral industries. Metal trade"

P. Gradl, Darren C. Tinker, A. Park et al.

Metal additive manufacturing (AM) encapsulates the myriad of manufacturing processes available to meet industrial needs. Determining which of these AM processes is best for a specific aerospace application can be overwhelming. Based on the application, each of these AM processes has advantages and challenges. The most common metal AM methods in use include Powder Bed Fusion, Directed Energy Deposition, and various solid-state processes. Within each of these processes, there are different energy sources and feedstock requirements. Component requirements heavily affect the process determination, despite existing literature on these AM processes (often inclusive of input parameters and material properties). This article provides an overview of the considerations taken for metal AM process selection for aerospace components based on various attributes. These attributes include geometric considerations, metallurgical characteristics and properties, cost basis, post-processing, and industrialization supply chain maturity. To provide information for trade studies and selection, data on these attributes were compiled through literature reviews, internal NASA studies, as well as academic and industry partner studies and data. These studies include multiple AM components and sample build experiments to evaluate (1) material and geometric variations and constraints within the processes, (2) alloy characterization and mechanical testing, (3) pathfinder component development and hot-fire evaluations, and (4) qualification approaches. This article summarizes these results and is meant to introduce various considerations when designing a metal AM component.

Rina Khan, Annabelle Sauve, Imaan Bayoumi et al.

Artificial intelligence (AI) in healthcare has led to many promising developments; however, increasingly, AI research is funded by the private sector leading to potential trade-offs between benefits to patients and benefits to industry. Health AI practitioners should prioritize successful adaptation into clinical practice in order to provide meaningful benefits to patients, but translation usually requires collaboration with industry. We discuss three features of AI studies that hamper the integration of AI into clinical practice from the perspective of researchers and clinicians. These include lack of clinically relevant metrics, lack of clinical trials and longitudinal studies to validate results, and lack of patient and physician involvement in the development process. For partnerships between industry and health research to be sustainable, a balance must be established between patient and industry benefit. We propose three approaches for addressing this gap: improved transparency and explainability of AI models, fostering relationships with industry partners that have a reputation for centering patient benefit in their practices, and prioritization of overall healthcare benefits. With these priorities, we can sooner realize meaningful AI technologies used by clinicians where mutua

Rajković Radmilo, Kržanović Daniel, Mikić Miomir et al.

The design of the final boundary of the intervention in the Eastern part of the South District open pit mine was carried out on the basis of a defined solid of the landslide and unstable zone in the space limited by the terrain topography, the upper surface, the boundary of the sliding plane, and the lower limiting surface. The solid was created on the basis of the geotechnical interpretation of the landslide and unstable zone, i.e. on the basis of defined vertical engineering-geological profiles, which represent closed polygons.

Vujić Jovan, Ilić Božo, Đenić Nebojša

The aim of this paper is to point out the electrical equipment that is subject to frequent break-downs in BELAZ dumpers75135, 75145 and other types of dumper trucks that are represented in our mines especially in open-pit mines. The transmission of power from the diesel engine to the drive wheels is carried out using a synchronous generator (electric generator) which is in an elastic connection with the diesel engine and the drive electric motors, which are located in the reducer wheels. The most common failures are on the electric generator that produces electric energy and the contactors with which it is produced management of power transmission from electric generator to electric engine. In the case of electric generators, failures mostly occur on the rotor: overheating of the poles of the rotor winding, which causes their burning as well as cracking of the so-called dovetail rotor half. The causes of these failures are mainly increased vibrations of the rotor poles themselves and are the result of improper balancing and loosening of the anchor bolts during the time. As the causes of failure are mostly mechanical in nature, we will devote special emphasis to that problem.

Rajković Radmilo, Kržanović Daniel, Mikić Miomir et al.

Geometrical elements for the construction of the open pit Severni revir of the Majdanpek copper mine were adopted based on the engineering-geological characteristics of the working environment, taking into account the applied work technology and the adopted mechanization, as well as based on previous work experience. This paper presents the results of geotechnical tests of the working environment, as well as the results of their stability calculations in accordance with current legislation.

Simić Željko

Coal-fired thermal power plants (TPPs) form the basis of the electric power systems of Bosnia and Herzegovina and Serbia, but at the same time they represent the largest sources of emissions of sulfur dioxide, nitrogen oxides, solid particles and carbon dioxide. These emissions significantly exceed EU limit values and complicate the process of alignment with EU environmental regulations. This paper examines the state of emissions in TPPs in Bosnia and Herzegovina and Serbia, with particular emphasis on outdated combustion and filtration technologies used in most facilities. Special attention is given to the TPP Stanari, which, thanks to the application of a circulating fluidized bed (CFB) boiler and fabric filters, achieves emission levels in line with EU standards. The findings suggest that TPP Stanari serves as an example of good practice in the region and a reference model for the modernization of other plants. It is concluded that the combination of energy efficiency and advanced emission control systems represents the only sustainable pathway for reducing the ecological consequences of the thermal energy sector.

Mansur Arief, Yasmine Alonso, CJ Oshiro et al.

The world is entering an unprecedented period of critical mineral demand, driven by the global transition to renewable energy technologies and electric vehicles. This transition presents unique challenges in mineral resource development, particularly due to geological uncertainty-a key characteristic that traditional supply chain optimization approaches do not adequately address. To tackle this challenge, we propose a novel application of Partially Observable Markov Decision Processes (POMDPs) that optimizes critical mineral sourcing decisions while explicitly accounting for the dynamic nature of geological uncertainty. Through a case study of the U.S. lithium supply chain, we demonstrate that POMDP-based policies achieve superior outcomes compared to traditional approaches, especially when initial reserve estimates are imperfect. Our framework provides quantitative insights for balancing domestic resource development with international supply diversification, offering policymakers a systematic approach to strategic decision-making in critical mineral supply chains.

Samuel Repka, Bořek Reich, Fedor Zolotarev et al.

We propose a novel Graph Neural Network-based method for segmentation based on data fusion of multimodal Scanning Electron Microscope (SEM) images. In most cases, Backscattered Electron (BSE) images obtained using SEM do not contain sufficient information for mineral segmentation. Therefore, imaging is often complemented with point-wise Energy-Dispersive X-ray Spectroscopy (EDS) spectral measurements that provide highly accurate information about the chemical composition but that are time-consuming to acquire. This motivates the use of sparse spectral data in conjunction with BSE images for mineral segmentation. The unstructured nature of the spectral data makes most traditional image fusion techniques unsuitable for BSE-EDS fusion. We propose using graph neural networks to fuse the two modalities and segment the mineral phases simultaneously. Our results demonstrate that providing EDS data for as few as 1% of BSE pixels produces accurate segmentation, enabling rapid analysis of mineral samples. The proposed data fusion pipeline is versatile and can be adapted to other domains that involve image data and point-wise measurements.

Craig Wright

This paper presents a comprehensive refutation of the so-called "blockchain trilemma," a widely cited but formally ungrounded claim asserting an inherent trade-off between decentralisation, security, and scalability in blockchain protocols. Through formal analysis, empirical evidence, and detailed critique of both methodology and terminology, we demonstrate that the trilemma rests on semantic equivocation, misuse of distributed systems theory, and a failure to define operational metrics. Particular focus is placed on the conflation of topological network analogies with protocol-level architecture, the mischaracterisation of Bitcoin's design--including the role of miners, SPV clients, and header-based verification--and the failure to ground claims in complexity-theoretic or adversarial models. By reconstructing Bitcoin as a deterministic, stateless distribution protocol governed by evidentiary trust, we show that scalability is not a trade-off but an engineering outcome. The paper concludes by identifying systemic issues in academic discourse and peer review that have allowed such fallacies to persist, and offers formal criteria for evaluating future claims in blockchain research.

Jef Caers

The energy transition through increased electrification has put the worlds attention on critical mineral exploration Even with increased investments a decrease in new discoveries has taken place over the last two decades Here I propose a solution to this problem where AI is implemented as the enabler of a rigorous scientific method for mineral exploration that aims to reduce cognitive bias and false positives drive down the cost of exploration I propose a new scientific method that is based on a philosophical approach founded on the principles of Bayesianism and falsification In this approach data acquisition is in the first place seen as a means to falsify human generated hypothesis Decision of what data to acquire next is quantified with verifiable metrics and based on rational decision making A practical protocol is provided that can be used as a template in any exploration campaign However in order to make this protocol practical various form of artificial intelligence are needed I will argue that the most important form are one novel unsupervised learning methods that collaborate with domain experts to better understand data and generate multiple competing geological hypotheses and two humanintheloop AI algorithms that can optimally plan various geological geophysical geochemical and drilling data acquisition where uncertainty reduction of geological hypothesis precedes the uncertainty reduction on grade and tonnage

Giada Biava, L. Depero, E. Bontempi

Mineral carbonation emerges as a promising technology to tackle a contemporary challenge: climate change. This method entails the interaction of carbon dioxide with metal-oxide-bearing materials to produce solid carbonates resembling common substances (chalk, antacids, or baking soda). Given that steelmaking industries contribute to 8% of the global total emissions annually, the repurposing of their by-products holds the potential to mitigate CO2 production. Steel slag is a by-product of the metallurgical industry which is suitable for capturing CO2 due to its chemical composition, containing high CaO (24%–65%) and MgO (3%–20%) amounts, which increases the reactivity with the CO2. Moreover, the carbonation process can improve the hydraulic and mechanical properties of steel slag, making this by-product interesting to be reused in building materials. Different studies have developed in the last years addressing the possibilities of reducing the environmental impact of steel products, by CO2 sequestration. This study is dedicated to reviewing the basics of mineral carbonation applied to steel slag, along with recent advancements in research. Special emphasis is placed on identifying parameters that facilitate the reactions and exploring potential applications for the resulting products. The advantages and disadvantages of steel slag carbonation for the industrialization of the process are also discussed.

Stevanović Marija, Jovanović Violeta, Simonović Danijela et al.

The driver of modern world industry is electricity. Production, distribution and use of electricity affect the functioning of modern industrial plants, the process of communication in the modern world, as well as numerous other types of services that are necessary for people's lives. The technological process of coal-based electricity production contributes to the increased emission of gases that have a large negative impact on the environment. Carbon dioxide (CO2 ), sulfur dioxide (SO2 ), nitrogen oxides (NOx ), carbon monoxide (CO) and solid PM particles are the main constituents of polluting gases from thermal power plants. All the mentioned compounds have harmful effects on the environment, and in the long term they also affect climate change (greenhouse effect). Due to the aforementioned problems, it is important to apply the principles of corporate social responsibility to companies in the energy sector. The aim of the paper is to evaluate the impact of the organizational structure of the company on the development of the system of corporate social responsibility in companies from the energy sector. The research results confirmed the positive impact of the organizational structure on socially responsible business practices

Marković Nenad, Jakšić Uroš, Rilak Vladimir et al.

The aim of the paper is to present the method of implementing and using relay protection with a special emphasis on microprocessor relay protection in Electric power distribution Kruševac, and based on the presented concrete examples of settings and operation of protective devices that were collected from practice and paper in the field. The software packages Test Universe were used in the paper for testing protection in TS "Kruševac 1" on the 1158B transmission line in the direction of "Kruševac 4" on the 110 kV network, as wel as Test Universe software package for testing protection in TS "Kruševac 1" on the 1158B transmission line in the direction of "Kruševac 4" on the 110 kV network. During the test, movement of the current and voltage values, disconnection times, as well as characteristics that show operation of each protection were monitored on the computer. The paper in the practical part shows the detailed connection of the equipment for testing the functions of the microprocessor protection relay of the 110 kV transmission line. For a specific transmission line, parameters, images of devices and complete test equipment, as well as official test lists with actual tripping values are provided. Advantage of modern microprocessor relays reflects in the fact that all functions are combined in one compact box that communicate with each other using special protocols and thus facilitate the work of users.

Jiyoon Pyo, Yao-Yi Chiang

Record linkage integrates diverse data sources by identifying records that refer to the same entity. In the context of mineral site records, accurate record linkage is crucial for identifying and mapping mineral deposits. Properly linking records that refer to the same mineral deposit helps define the spatial coverage of mineral areas, benefiting resource identification and site data archiving. Mineral site record linkage falls under the spatial record linkage category since the records contain information about the physical locations and non-spatial attributes in a tabular format. The task is particularly challenging due to the heterogeneity and vast scale of the data. While prior research employs pre-trained discriminative language models (PLMs) on spatial entity linkage, they often require substantial amounts of curated ground-truth data for fine-tuning. Gathering and creating ground truth data is both time-consuming and costly. Therefore, such approaches are not always feasible in real-world scenarios where gold-standard data are unavailable. Although large generative language models (LLMs) have shown promising results in various natural language processing tasks, including record linkage, their high inference time and resource demand present challenges. We propose a method that leverages an LLM to generate training data and fine-tune a PLM to address the training data gap while preserving the efficiency of PLMs. Our approach achieves over 45\% improvement in F1 score for record linkage compared to traditional PLM-based methods using ground truth data while reducing the inference time by nearly 18 times compared to relying on LLMs. Additionally, we offer an automated pipeline that eliminates the need for human intervention, highlighting this approach's potential to overcome record linkage challenges.

Álvaro I. Riquelme

In various geosciences branches, including mineral exploration, geometallurgical characterization on established mining operations, and remote sensing, the regionalized input variables are spatially well-sampled across the domain of interest, limiting the scope of spatial uncertainty quantification procedures. In turn, response outcomes such as the mineral potential in a given region, mining throughput, metallurgical recovery, or in-situ estimations from remote satellite imagery, are usually modeled from a much-restricted subset of testing samples, collected at certain locations due to accessibility restrictions and the high acquisition costs. Our limited understanding of these functions, in terms of the multi-dimensional complexity of causalities and unnoticed dependencies on inaccessible inputs, may lead to observing changes in such functions based on their geographical location. Pooling together different response functions across the domain is critical to correctly predict outcome responses, the uncertainty associated with these inferred values, and the significance of inputs in such predictions at unexplored areas. This paper introduces the notion of a dual random field (dRF), where the response function itself is considered a regionalized variable. In this way, different established response models across the geographic domain can be considered as observations of a dRF realization, enabling the spatial inference and uncertainty assessment of both response models and their predictions. We explain how dRFs inherit all the properties from classical random fields, allowing the use of standard Gaussian simulation procedures to simulate them. These models are combined to obtain a mineral potential response, providing an example of how to rigorously integrate machine learning approaches with geostatistics.

Mohammad Nooraiepour, Mohammad Masoudi, Beyene Girma Haile et al.

Subsurface fluid flow and solute transport are pivotal in addressing pressing energy, environmental, and societal challenges, such as geological CO2 storage. Basaltic rocks have gained prominence as suitable geological substrates for injecting substantial CO2 volumes and carbon mineralization, driven by their widespread occurrence, high concentrations of cation-rich silicate minerals, reported fast mineralization rate, and favorable characteristics such as porosity, permeability, and injectivity. The mineralization process within basaltic rocks is intricately linked, involving the dissolution of silicate minerals and the subsequent precipitation of carbonate minerals. Columnar flow and batch surface growth experiments revealed the spontaneous formation of a limited number of large crystals at various locations, rationalized by the overarching influence of probabilistic mineral nucleation. Experiments with CO2-acidified brine versus freshwater prove to be more challenging regarding the sweet spots for heavy carbon mineralization due to clay formation on the surface, particularly smectites. Despite numerical predictions suggesting the formation of MgFeCa-carbonates in CO2-basalt interactions at higher temperatures, our laboratory findings primarily indicated the growth of calcium carbonates. The experimental and numerical outcomes highlight the necessity of a probabilistic approach for accurately modeling reaction kinetics, crystal growth distribution, and the dynamic interplay between reactive flow, geochemical reactions, mineral carbonation, and geometry alteration.

I. Gyollai, S. Biri, Z. Juhász et al.

Context. Identifying minerals on asteroid surfaces is difficult as space weathering modifies the minerals infrared spectra. This shouldbe better understood for proper interpretation. Aims. We simulated the space weathering effects on a meteorite and recorded the alterations of the crystalline structure, such as the change in peak positions and full width at half maximum values. Methods. We used proton irradiation to simulate the effects of solar wind on a sample of NWA 10580 CO3 chondrite meteorites. After irradiation in three gradually increased steps with 1 keV ion energy, we used infrared microscopic reflectance and diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) to identify and understand the consequences of irradiation. Results. We find negative peak shifts after the first and second irradiations at pyroxene and feldspar minerals, similarly to the literature, and this shift was attributed to Mg loss. However, after the third irradiation a positive change in values in wavenumber emerged for silicates, which could come from the distortion of SiO4 tetrahedra, resembling shock deformation. The full width at half maximum values of major bands show a positive (increasing) trend after irradiations in the case of feldspars, using IR reflection measurements. Comparing DRIFTS and reflection infrared data, the peak positions of major mineral bands were at similar wavenumbers, but differences can be observed in minor bands. Conclusions. We measured the spectral changes of meteorite minerals after high doses of proton irradiation for several minerals. We show the first of these measurements for feldspars; previous works only presented pyroxene, olivine, and phyllosilicates.

S. Majodina, Olwethu Poswayo, T. Dembaremba et al.

Mineral materials play a pivotal in heterogeneous catalysts as active, support, or promoter components, with the oil refinery industry being one of the biggest beneficiaries. While conventional hydroprocessing catalysts have historically met the industry’s needs, the growing need to accommodate unique feedstocks, meet the increasing demand for environmentally acceptable products, obtain better product specifications, enhance selectivity for reactions to increase ratios for certain product cuts, and use more cost-effective and abundant mineral materials, has recently motivated for fresh considerations in the development of hydroprocessing catalysts. Based on periodic trends, noble metals possess the most desirable qualities, but their relative abundance in the Earth’s crust is too low to meet industry needs. They are costly and highly sensitive to sulfur poisoning. Mo and W lie in the sweet spot, but it is anticipated that they cannot meet the increasing demand. Investigations of electronic interactions of more economical and abundant metals, such as Nb, V, and Fe, with other elements and support materials have yielded a better understanding of synergistic effects that help to access noble metal-like qualities. This work contrasts conventional hydroprocessing catalysts and recently improved catalysts, detailing the chemistry considerations behind the selection of mineral materials used in the catalysts. It also explores how further manipulation of these mineral materials and synthesis approaches is driving toward more desirable properties. The work brings to the attention of the readers the challenges and opportunities for the further improvement of hydroprocessing catalysts to ensure environmental sustainability while meeting the industry’s growing needs.

A. Sidorov

The article examines the current trends in Russia’s foreign trade with the EU and China in the context of sanctions restrictions imposed by “unfriendly” countries.Aim. The study aims to explore current trends in Russia’s foreign trade in goods with the EU and China in 2022.Objectives. The author conducts an analysis of the dynamics of Russia’s trade with the EU and China; identifies the main commodity groups that have contributed to the changes in trade with the EU and China; explores the impact of sanctions restrictions on Russia’s trade with the EU; assesses the possibilities of reorienting Russia’s foreign trade towards China.Methods. The main methods are the analysis of current statistics of foreign trade in goods between the EU and China; a comparative analysis of the dynamics of trade in commodity groups and individual goods with the EU and China; method of mirror statistics (due to the suspension of the publication of official data by the Federal Customs Service (FCS) of Russia).Results. The analysis shows a decrease in trade turnover between Russia and the EU and its growth with China. With the EU the decline in exports was mainly due to metal industry products, chemical products, precious stones and metals, and timber; in imports —  at the expense of machinery and equipment. Trade with China in the main commodity groups has expanded, most significantly in terms of exports —  in chemical products, in terms of imports —  in machinery and equipment.Conclusions. The role of Russian exports of mineral fuels and energy as the basis for trade with the EU and China in 2022 has strengthened in the face of sanctions restrictions and rising prices. Russia’s trade with the EU reduced mainly due to the sanctioned goods. The reorientation of Russia’s foreign trade towards China is partially possible, with the restraining factors: in terms of imports —  China’s lack of strong positions in certain high-tech goods; in terms of exports —  objective limitations on China’s domestic market capacity, a slowdown in economic growth, a decrease in the energy intensity of the economy, competition with Russia.

Sovrlić Zorica, Kalinović Lidija, Vasiljević Sanela et al.

Waste oils are dangerous waste, because they can contain high concentrations of metals, hydrocarbons, PAHs, chlorinated compounds, phenols and other substances that come from additives and are created as a result of the operation of different types of engines. This type of waste can cause major problems and contamination of the environment, both soil and water, if they are not treated in the right way and they are wasted. Their identification and further characterization as hazardous waste according to the waste regulations of the Republic of Serbia - Rulebook on categories, testing and classification of waste ("Official Gazette of the RS" no. 56/2010, 93/2019, 39/2021) and Rulebook on the conditions, method and procedure of waste oil management ("Official Gazette of the RS", no. 71/2010). In this paper, GC/MS analysis of different types of waste oils (engine, hydraulic, machine, mineral non-chlorinated oil, synthetic oil) was performed. The obtained chromatograms were compared with the chromatogram of the standard (Dr. Ehrenstorfer) which contains the same ratio of diesel oil and mineral oil without additives. In this way, the analysis of the so-called "fingerprint" and characterization for different types of waste oils was performed, which is very important for comparison with analysis of oil in natural samples (water, soil) in order to determine the original source of pollution.