Hydrocarbon separation is one of the most critically important and complex industrial separation processes, offering versatile bulk chemicals and vital support to the national economy. Traditional separation technologies, such as cryogenic distillation and solvent extraction, are energy-intensive and cause serious environmental stress. Moreover, the growth of industries and technologies and the greater requirements for products (e.g., purity) lead to challenges that cannot be met using traditional separation methods. Adsorptive and membrane-based separations are recognized as energy-efficient alternatives by which to revolutionize the current energy-intensive conditions and satisfy the new demands. This critical review presents the recent progress in metal-organic frameworks (MOFs) and related membranes (e.g., continuous MOF membranes and mixed-matrix membranes) for hydrocarbon separation. The contributions of the underlying separation mechanisms (e.g., enthalpy-driven thermodynamic equilibrium, molecular sieving, kinetic separation based on molecular size, and combined mechanisms) and the adopted strategies (e.g., defect and microstructure control, membrane thickness and interfacial compatibility) to the breaking of trade-off (e.g., permeability/selectivity and capacity/selectivity) and the design of novel materials and processing technologies are discussed. Moreover, this review also summarizes the potential barriers that exist from the academic to the ultimate industrial implementations and the prospects of future development.
Trujić Stefan, Marinčić Anđela, Novković Željana
et al.
Detailed geological and engineering-geological investigations of the coal zone and the Eastern field of the Gacko coal basin were carried out to provide reliable bases for mining design and operation of the Gacko thermal power plant. The investigations, carried out in accordance with the applicable regulations and project documentation, included 28 drillholes and a wide range of laboratory tests with the aim of defining the qualitative and quantitative parameters of coal and re-categorizing reserves to category A. Special emphasis was placed on the analysis of the stratification of coal seams and the characteristics of accompanying sediments, which is crucial for the selection of the optimal coal purification technology. The results obtained represent the basis for further classification of reserves, mining design and exploitation planning.
Mining engineering. Metallurgy, Mineral industries. Metal trade
Impulse generators with RC circuits form the foundation for producing surge voltages used in high-voltage equipment testing. In high-voltage engineering literature, the expressions for impulse voltage waveforms include known parameters of lightning or switching overvoltages, which are used to determine the amplitudes and time constants of impulse overvoltages in RC discharge circuits. However, both standards and scholarly publications often lack clarification for various ambiguities-such as the commonly cited factor of 1.67 for rise time-without providing rigorous physical or mathematical justification. All overvoltage parameters are typically defined axiomatically, and the existing formulas for designing impulse voltage generators are often inadequate. This paper presents implemented formulas and derived solutions that enable accurate determination of all parameters and electrical quantities of an RC circuit generating a specified impulse voltage waveform. For method verification, an adapted module of the MATLAB simulation package, psbsurgeovervoltage.mdl, was employed.
Mining engineering. Metallurgy, Mineral industries. Metal trade
Priyanka Kumari, Sampriti Soor, Amba Shetty
et al.
Accurate mineral identification on the Martian surface is critical for understanding the planet's geological history. This paper presents a UNet-based autoencoder model for efficient spectral preprocessing of CRISM MTRDR hyperspectral data, addressing the limitations of traditional methods that are computationally intensive and time-consuming. The proposed model automates key preprocessing steps, such as smoothing and continuum removal, while preserving essential mineral absorption features. Trained on augmented spectra from the MICA spectral library, the model introduces realistic variability to simulate MTRDR data conditions. By integrating this framework, preprocessing time for an 800x800 MTRDR scene is reduced from 1.5 hours to just 5 minutes on an NVIDIA T1600 GPU. The preprocessed spectra are subsequently classified using MICAnet, a deep learning model for Martian mineral identification. Evaluation on labeled CRISM TRDR data demonstrates that the proposed approach achieves competitive accuracy while significantly enhancing preprocessing efficiency. This work highlights the potential of the UNet-based preprocessing framework to improve the speed and reliability of mineral mapping on Mars.
This paper proposes a machine learning-based approach for identifying honey floral and geographical sources using mineral element profiles. The proposed method comprises two steps: preprocessing and classification. The preprocessing phase involves missing-value treatment and data normalization. In the classification phase, we employ various supervised classification models for discriminating between six botanical sources and 13 geographical origins of honey. We test the classifiers' performance on a publicly available honey mineral element dataset. The dataset contains mineral element profiles of honeys from various floral and geographical origins. Results show that mineral element content in honey provides discriminative information useful for classifying honey botanical and geographical sources. Results also show that the Random Forests (RF) classifier obtains the best performance on this dataset, achieving a cross-validation accuracy of 99.30% for classifying honey botanical origins and 98.01% for classifying honey geographical origins.
Nickel (Ni) is fundamentally important to the modern world for stainless steel, specialty alloys, electroplating, batteries, and other uses. Global Ni demand is expected to soar as the world transitions to a net-zero greenhouse gas emissions economy based on electric vehicles and energy storage batteries linked to renewable energy systems. This means that understanding the current Ni sector, especially known Ni resources, reserves, and mining (i.e., current and likely future sources of this metal), is crucial to enabling this energy transition, including the likely environmental, social, and governmental challenges that may prevent the development or may hinder the continuation of future and current Ni mining operations. This paper achieves this by presenting a comprehensive global assessment of reported Ni deposits and projects for the year 2018. All of these are classified by mineral deposit type to understand the relative importance of the different mineral systems that are mined for Ni and allocate each site a primary and secondary mineral deposit type. We also compare our results for 2018 with the results of a previous study focused on 2011 data to understand how deposits and projects have evolved over time and coincident with production. The majority of Ni has been and will continue to be sourced from laterites and magmatic sulfide systems; other deposits have produced only minor amounts of Ni. Our database indicates that globally some 627 Ni deposits remain with in-ground resources and/or reserves, including 148 and 86 laterite, 248 and 93 magmatic sulfide, 33 and 14 hydrothermal, and three and two tailings Ni-containing code-and noncode-compliant resources, respectively. Projects with reserve estimates include 38 laterite reserves, 70 magmatic sulfide, and three hydrothermal Ni-containing reserves. These data yield 350.2 million metric tonnes (Mt) of contained Ni in resources distributed as 190.2, 124.1, and 35.4 Mt Ni in laterite, magmatic sulfide, and hydrothermal resources, respectively. Reserves contain 47.12 Mt of Ni split into 25.97, 20.14, and 1.01 Mt Ni in laterite, magmatic sulfide, and hydrothermal reserves, respectively. Comparison of these data to 2011 data indicates that sulfide deposits are effectively keeping pace with depletion by mining, whereas laterite resources are lower than in 2011, perhaps reflecting the fact that the latter can be more comprehensively assessed during the early stage of laterite resource and reserve estimation. This suggests that although current resources are sufficient to enable current production to be sustained, the expected increase in demand for Ni may act to constrain supply. This may also be exacerbated by the increasing environmental, social, and governmental challenges facing the minerals industry globally, with a number of projects that have faced delays or problems associated with these challenges also outlined in this study. Our study also highlights the variable level of sustainability reporting undertaken by different companies involved in Ni mining and exploration. One potential approach to more effective environmental and social engagement would be improvements in this area, allowing more transparent engagement with social and environmental stakeholders. Overall, known Ni resources and reserves are sufficient to continue current levels of production for several decades to come (assuming all of this material can be mined); however, the Ni mining sector faces a number of challenges that may change this, including increased demand from electric vehicles and batteries and potential supply restrictions relating to increased environmental, social, and governmental challenges to the mining industry globally.
Živanović Miloš, Miljković Nikola, Stefanović Jelena
et al.
This paper will cover the Preliminary Design of the by-products transport system after the Ecological reconstruction of the thermal power plant Pljevlja. The 4.5 km belt conveyor long route enters the tunnel at Borovica Lake. Tunnel position is in relation to the route, the cross-section selection, calculation of structural elements and fitting into the ambient unit around the lake are described.
Mining engineering. Metallurgy, Mineral industries. Metal trade
Technological parameters also have an impact on the environment due to the exploitation of the ore deposit. Therefore, it is necessary to analyze and assess environmental risks in the approved exploitation area and take measures and conditions to prevent, reduce and eliminate harmful impacts on the environment and human health. The aim of the paper is to emphasize that it is important to manage the environment, that measures should be determined and taken to eliminate, prevent and reduce environmental impacts in order to meet the conditions for further uninterrupted operation of the mine without violating legal provisions regarding environmental protection.
Mining engineering. Metallurgy, Mineral industries. Metal trade
Freja Thoresen, Igor Drozdovskiy, Aidan Cowley
et al.
This paper presents a novel method for mapping spectral features of the Moon using machine learning-based clustering of hyperspectral data from the Moon Mineral Mapper (M3) imaging spectrometer. The method uses a convolutional variational autoencoder to reduce the dimensionality of the spectral data and extract features of the spectra. Then, a k-means algorithm is applied to cluster the latent variables into five distinct groups, corresponding to dominant spectral features, which are related to the mineral composition of the Moon's surface. The resulting global spectral cluster map shows the distribution of the five clusters on the Moon, which consist of a mixture of, among others, plagioclase, pyroxene, olivine, and Fe-bearing minerals across the Moon's surface. The clusters are compared to the mineral maps from the Kaguya mission, which showed that the locations of the clusters overlap with the locations of high wt% of minerals such as plagioclase, clinopyroxene, and olivine. The paper demonstrates the usefulness of unbiased unsupervised learning for lunar mineral exploration and provides a comprehensive analysis of lunar mineralogy.
In this paper, the focus is on improving the efficiency and precision of mineral data collection using UAVs by addressing key challenges associated with sensor integration. These challenges include mitigating electromagnetic interference, reducing vibration noise, and ensuring consistent sensor performance during flight. The paper demonstrates how innovative approaches to these issues can significantly transform UAV-assisted mineral data collection. Through meticulous design, testing, and evaluation, the study presents experimental evidence of the efficacy of these methods in collecting mineral data via UAVs. The advancements achieved in this research enable the UAV platform to remain airborne up to 6$\times$ longer than standard battery-powered multirotors, while still gathering high-quality mineral data. This leads to increased operational efficiency and reduced costs in UAV-based mineral data-gathering processes
This paper presents an innovative end-to-end workflow for mineral exploration, integrating ambient noise tomography (ANT) and artificial intelligence (AI) to enhance the discovery and delineation of mineral resources essential for the global transition to a low carbon economy. We focus on copper as a critical element, required in significant quantities for renewable energy solutions. We show the benefits of utilising ANT, characterised by its speed, scalability, depth penetration, resolution, and low environmental impact, alongside artificial intelligence (AI) techniques to refine a continent-scale prospectivity model at the deposit scale by fine-tuning our model on local high-resolution data. We show the promise of the method by first presenting a new data-driven AI prospectivity model for copper within Australia, which serves as our foundation model for further fine-tuning. We then focus on the Hillside IOCG deposit on the prospective Yorke Peninsula. We show that with relatively few local training samples (orebody intercepts), we can fine tune the foundation model to provide a good estimate of the Hillside orebody outline. Our methodology demonstrates how AI can augment geophysical data interpretation, providing a novel approach to mineral exploration with improved decision-making capabilities for targeting mineralization, thereby addressing the urgent need for increased mineral resource discovery.
Abstract Global warming is one of the most significant issues of today. Carbon dioxide is the primary contributor to climate change, and is mainly formed by the energy sector; thus, it is imperative to expand the total decarbonisation of this industry. Another global concern is the high demand and low supply of critical metals due to the constant growth of technological advances. These elements are essential for the manufacturing of advanced technology, green technology, and emerging industries. Currently, there is global tension and unrest over how the critical metals market is developing, with one example regarding China, which has an apparent monopoly on the mining, refining, and technical expertise associated with rare earth elements. China currently provides approximately 90% of the production of rare earth elements, causing conflicts with the European Union, the USA, and Japan due to their dependence on these raw materials. Another controversial case is the production of cobalt in the Democratic Republic of the Congo, which dominates in the global production (60% of the world’s production of Co). Despite this, the Democratic Republic of the Congo is one of the poorest countries in the world. The constant depletion of high-grade minerals from the Earth's surface forces the search for new alternative sources of the critical metals. The abundance of minerals within the sea is of relevance, with large deposits of marine nodules, ferromanganese crusts, and massive polymetallic sulphides. These are of great interest to the mining industry, as it is estimated that the largest reserves of various critical metals are found on the seabed, in addition to the largest reserves of cobalt, nickel, and manganese, and a considerable amount of rare earth elements. The exploitation of mineral resources from the seabed by the company Deep Sea Mining Finance Limited (DSMF) is currently being developed, which might promote the expansion of this market throughout the world. The wealth of minerals in the seabed may be a solution to the shortage of critical metals in the market, may decrease political tensions between countries worldwide, and may promote the large-scale deployment of renewable energy.
Critical minerals are the cornerstone of the new round of the industrial revolution. The global division of labor established under the traditional technology, industry, and trade systems is facing a significant restructuring. Global economic and technological changes will lead to a long-term increase in demand for critical minerals. The critical minerals supply chain is rife with political interference and distorted trade practices compared to the robust resource demand. It faces several challenges that threaten the sustainability of the supply chain. We analyze the evolving security connotation of critical minerals supply chains. We also provide an overview of research on quantifying risks of critical minerals from two aspects: security evaluation mechanism and global value chain. The interdisciplinary research techniques and methods are more adapted to the new trends of international competition in critical minerals. The article reviews relevant security risk identification and response research in critical minerals supply chains. It analyzes how to address the risk challenges from national strategies. Finally, the article explores new trends under new technological revolution and industrial change.
ABSTRACT Rising mining costs and fewer high-grade ore deposits have necessitated a search for alternative methods for the recovery of metals from deposits that are no longer economically or environmentally exploitable by conventional mining. One such alternative method is in-situ recovery (ISR). Although ISR has typically been used for mining uranium ores that are not economic to mine with conventional methods, it has also been used less frequently for the treatment of other low permeability rocks, such as hard rocks containing copper, nickel, and gold. The reason for the limited uptake of the technology for hard rock mineralization is primarily due to the low natural rock porosity and permeability and hence limited ability of a lixiviant to permeate the rock and contact the minerals. This review focuses on three novel potential access creation methods: microwaves, high-voltage pulses, and cryogenic fracturing procedures. Most research studies of microwaves and high voltage pulses have focused on energy savings in comminution, but little research has been done on their application of in ISR. In situ cryogenic fracturing has been used in the petroleum industry and may be a potential novel option for use for the in situ recovery of minerals in the mining industry. The aim of this review is to summarize available information on these three methods for increasing the permeability of hard rocks and thereby improving the rate of lixiviant-mineral contact and mass transfer in in-situ recovery. The review will start with an overview of considerations for the use of ISR. The mechanisms of microwave, high-voltage pulse, and cryogenic fracturing methods will then be discussed.
The mineral economics of rare-earth elements (REEs) are a crucial factor in the development of new REE mineral exploration and mining projects as well as being defining factors in the security of supply and the determination of the criticality (vulnerability to supply restriction for a variety of factors that can cause supply–demand imbalances) of this group of elements. Production and, more importantly, refining of REEs remains focused in China, leading to a national monopoly that could cause future supply constraints and price volatility. Variations in the demand for individual REEs are demonstrated by December 2020 prices that varied between ~ USD$1.8/kg for samarium (Sm) oxides and ~ USD$2.15/kg for cerium (Ce) oxides to ~ $1305/kg for terbium (Tb) metal, reflecting lower supply and higher demand for Tb relative to Sm and Ce. Price variations between individual REEs are far greater than short-term fluctuations in the prices of an individual REE product. The higher prices for certain REEs, such as neodymium (Nd), dysprosium (Dy), and Tb, create further issues when compared with primary REE supply from orebodies, which is typically dominated by Lanthanum (La), Ce, and the other light REEs (LREEs). This balance problem is just one aspect of the lack of security of supply of REEs, with others including the small size and limited transformational growth potential of the sector relative to other parts of the minerals industry, volatile REE prices, and the geographical distribution of REE mining and (especially) processing and refining. These factors mean that long-term planning in this sector is difficult, especially relative to the ~ 10–20 years needed to bring a mineral exploration project into production. The range of problems affecting REE supply, including securing further domestic supplies within countries that either do not or only have limited current REE extraction or development of secondary resources of these elements, strongly suggests that policymaking and associated geopolitical approaches to secure imports of REEs will be vital tools in reducing the REE criticality and security of supply issues that face many countries who rely on secure access to primary REE supply. Global mineral and metal production from 1956 to 2018 normalized to 1956 production (a) and in per capita terms normalized to 1956 production (b) showing the increase in global mineral and metal use per head of population with dashed lines indicate elements with lower normalized production in 2021 than in 1956. These diagrams effectively demonstrate the increase in the mineral and metal requirements for modern life, especially given the increase in recycling of a significant proportion of these commodities over the same period. The increase in demand for rare-earth elements (REEs) is especially visible, with modern society using ~ 12 times more REE per person in 2018 compared to 1956 and with primary REE production from mining some ~ 32 times higher in 2018 compared to 1956.
Handicraft is the backbone of rural economy of countries of South Asia and Southeast Asia. Bell metal handicraft known as “Dhokra craft,” is an important metal handicraft practiced in India. Commercialization of this craft industry has increased working hours but the business model is still cottage‐based. Manual manufacturing for commercial needs has increased incidence of hand injuries among the artisans affecting sustainable growth. The objective of this research is to find the cause of work‐related hand injuries of the artisans of bell metal handicraft industry to provide direction for future research. Occupational risk on hands were identified using Modified Dutch Musculoskeletal Questionnaire. Severity of hand symptoms were assessed by Modified Boston Hand Evaluation Questionnaire. Direct observation and task analysis was further used to understand the risk involved in the job. Use of hand tools and power tools play significant role in the development of hand injuries among the artisans. Hand problems such as amputation, burning marks, loss of sensitivity, and tingling sensation were highly observed among artisans, those with experience >31 years. Experienced artisans undergo more occupational hand injuries, causing absenteeism, job turnover, and job loss. This ultimately affects the sustainable growth of the Dhokra trade community.
Marie-Luise Steinmeyer, Peter Woitke, Anders Johansen
Protoplanets growing within the protoplanetary disk by pebble accretion acquire hydrostatic gas envelopes. Due to accretion heating, the temperature in these envelopes can become high enough to sublimate refractory minerals which are the major components of the accreted pebbles. Here we study the sublimation of different mineral species and determine whether sublimation plays a role during the growth by pebble accretion. For each snapshot in the growth process, we calculate the envelope structure and sublimation temperature of a set of mineral species representing different levels of volatility. Sublimation lines are determined using and equilibrium scheme for the chemical reactions responsible for destruction and formation of the relevant minerals. We find that the envelope of the growing planet reaches temperatures high enough to sublimate all considered mineral species when the mass is larger than 0.4 Earth masses. The sublimation lines are located within the gravitionally bound envelope of the planet. We make a detailed analysis of the sublimation of FeS at around 720 K, beyond which the mineral is attacked by H2 to form gaseous H2S and solid Fe. We calculate the sulfur concentration in the planet under the assumption that all sulfur released as H2S is lost from the planet by diffusion back to the protoplanetary disk. Our calculated values are in good agreement with the slightly depleted sulfur abundance of Mars, while the model overpredicts the extensive sulfur depletion of Earth by a factor of approximately 2. We show that a collision with a sulfur-rich body akin to Mars in the moon-forming impact lifts the Earth's sulfur abundance to approximately 10% of the solar value for all impactor masses above 0.05 Earth masses.
Aleksandra Pachalieva, Jeffrey D. Hyman, Daniel O'Malley
et al.
We perform a set of flow and reactive transport simulations within three-dimensional fracture networks to learn the factors controlling mineral reactions. CO$_2$ mineralization requires CO$_2$-laden water, dissolution of a mineral that then leads to precipitation of a CO$_2$-bearing mineral. Our discrete fracture networks (DFN) are partially filled with quartz that gradually dissolves until it reaches a quasi-steady state. At the end of the simulation, we measure the quartz remaining in each fracture within the domain. We observe that a small backbone of fracture exists, where the quartz is fully dissolved which leads to increased flow and transport. However, depending on the DFN topology and the rate of dissolution, we observe a large variability of these changes, which indicates an interplay between the fracture network structure and the impact of geochemical dissolution. In this work, we developed a machine learning framework to extract the important features that support mineralization in the form of dissolution. In addition, we use structural and topological features of the fracture network to predict the remaining quartz volume in quasi-steady state conditions. As a first step to characterizing carbon mineralization, we study dissolution with this framework. We studied a variety of reaction and fracture parameters and their impact on the dissolution of quartz in fracture networks. We found that the dissolution reaction rate constant of quartz and the distance to the flowing backbone in the fracture network are the two most important features that control the amount of quartz left in the system. For the first time, we use a combination of a finite-volume reservoir model and graph-based approach to study reactive transport in a complex fracture network to determine the key features that control dissolution.