Search Results (1,833)

This article explores the use of waste from polymetallic combines in South Kazakhstan, specifically tailings from the Achisay and Ansay deposits, as aggregates (crushed stone, sand) and mineral additives (dispersed barite powder) for producing concrete with specified operational properties. These secondary raw materials are now abundant in relation to their use, which makes them an affordable and accessible alternative for the manufacturing of concrete while also promoting environmental sustainability. X-ray diffraction, differential thermal analysis, and scanning electron microscopy of enriched barite ores in these tailings revealed valuable components, such as calcite, quartzite, and dolomite, suitable for use as aggregates and mineral additives. The calcite and quartzite content in the Ansay samples exceeds that in the Achisay samples. Concrete mixes with various proportions of crushed stone and sand from these tailings were prepared, and their working characteristics were analyzed. The impacts of filler content and grain composition on the characteristics of concrete mixtures were identified, and the requirements for optimizing aggregate grain composition to produce heavy concrete with desired qualities were determined. Heavy concrete with densities from 2300 to 2839 kg/m³ and compressive strengths from 41.6 to 58.2 MPa was developed. Physical and mechanical properties, including density, water absorption, frost resistance, and compressive strength, were also evaluated, confirming the feasibility of using technogenic waste in composite heavy concrete production. Full article

Cell–cell communication and extracellular matrix (ECM) organization in a bone microenvironment are essential to replicate the bone microenvironment accurately. In this study, the extracellular matrix (ECM) was emulated by incorporating M13 phages, selected through phage display for displaying engineered peptides that mimic bone matrix proteins, into human osteoblast cultures to develop a three-dimensional bone model (3D BMP-Phage). Comprehensive analysis was performed to investigate: (i) the morphological development of spheroids, assessed by optical microscopy and quantified via fractal dimension analysis using box-counting algorithms; (ii) the biochemical composition of the extracellular matrix, evaluated by Raman spectroscopy; (iii) ECM protein deposition, analyzed through immunofluorescence staining; (iv) matrix mineralization, assessed by Alizarin Red staining and alkaline phosphatase (ALP) activity assay; and (v) osteogenic gene expression, measured by quantitative RT-PCR. The findings demonstrate that the 3D BMP-Phage model, facilitated by a cocktail of bone-mimicking peptides, enhances structural integrity, ECM complexity, mineralization, and osteogenic pathways compared to the control. This novel approach replicates key aspects of the bone microenvironment, providing a valuable platform for advanced physiological and regenerative medicine research under controlled conditions. Full article

In the mining of deep mineral resources and tunnel engineering, the degradation of mechanical properties and the evolution of energy of through-double-joint sandy slate under triaxial loading and unloading conditions are key scientific issues affecting the stability design of the project. The existing research has insufficiently explored the joint inclination angle effect, damage evolution mechanism, and energy distribution characteristics of this type of rock mass under the path of increasing axial pressure and removing confining pressure. Based on this, in this study, uniaxial compression, conventional triaxial compression and increasing axial pressure, and removing confining pressure tests were conducted on four types of rock-like materials with prefabricated 0°, 30°, 60°, and 90° through-double-joint inclinations under different confining pressures. The axial stress/strain curve, failure characteristics, and energy evolution law were comprehensively analyzed, and damage variables based on dissipated energy were proposed. The test results show that the joint inclination angle significantly affects the bearing capacity of the specimen, and the peak strength shows a trend of first increasing and then decreasing with the increase in the inclination angle. In terms of failure modes, the specimens under conventional triaxial compression exhibit progressive compression/shear failure (accompanied by rock bridge fracture zones), while under increased axial compression and relief of confining pressure, a combined tensioning and shear failure is induced. Moreover, brittleness is more pronounced under high confining pressure, and the joint inclination angle also has a significant control effect on the failure path. In terms of energy, under the same confining pressure, as the joint inclination angle increases, the dissipated energy and total energy of the cemented filling body at the end of triaxial compression first decrease and then increase. The triaxial compression damage constitutive model of jointed rock mass established based on dissipated energy can divide the damage evolution into three stages: initial damage, damage development, and accelerated damage growth. Verified by experimental data, this model can well describe the damage evolution characteristics of rock masses with different joint inclination angles. Moreover, an increase in the joint inclination angle will lead to varying degrees of damage during the loading process of the rock mass. The research results can provide key theoretical support and design basis for the stability assessment of surrounding rock in deep and high-stress plateau tunnels, the optimization of support parameters for jointed rock masses, and early warning of rockburst disasters. Full article

Carlin-type gold deposits in southwestern Guizhou, China require systematic exploration methods to identify deep and peripheral prospecting potential beyond known deposits. We conducted a 1:50,000-scale soil geochemical survey across 928 km² in the Nibao gold deposit and its surrounding areas, with a total of 8842 samples collected. Fifteen elements were systematically analyzed, with particular focus on pathfinder elements associated with Carlin-type gold mineralization. Building on previous comparative analyses of soil geochemical and tectono-geochemical characteristics, this research systematically examines the enrichment patterns of soil geochemistry and their significance for ore prospecting. The results demonstrate that (1) elements such as Au, As, Sb, Hg, W, and Mo show significant positive correlation and strong enrichment patterns, indicating excellent metallogenic potential; (2) 176 and 12 single- and composite-element anomalies were delineated, respectively, with HS-2, HS-3, and HS-7 anomalies exhibiting high intensity and distinct concentration zonation, similar to those of the high factor score distribution of Au-As-Sb-Hg-W-Mo; (3) three prospecting targets were identified based on anomaly characteristics and geological conditions, including Nibao, Baogudi, and Sandaogou; (4) multiple mineralized bodies were revealed through engineering verification, indicating good prospecting potential in the deep and surrounding areas of the targets. These findings provide a scientific basis for further exploration of Carlin-type gold deposits in the study area and southwestern Guizhou. Full article

Aging of asphalt is a major cause of pavement distress. While regenerators restore aged asphalt, their mechanisms and efficacy differences remain unclear. This study quantified the repair effects of waste bio-oil (WBO) and mineral oil (MO) rejuvenators on aged asphalt binder using a comprehensive characterization approach. Conventional properties (penetration, softening point, ductility), functional groups (FT-IR), thermal stability (TG), differential scanning calorimetry (DSC), and dynamic shear rheology (DSR) were analyzed. Results reveal distinct mechanisms: WBO acts chemically via polar molecules, selectively reducing oxygen-containing groups and significantly improving ductility, while MO acts physically through light components that dilute viscosity, exhibiting weaker chemical repair. WBO-regenerated asphalt showed a lower thermal-oxidative peak temperature, superior low-temperature ductility, and enhanced high-temperature rheological performance (higher rutting factor, optimized viscoelasticity). These mechanistic differences—chemical restoration (WBO) versus physical replenishment (MO)—determine performance outcomes at the binder level. The findings provide a theoretical basis for regenerator selection in pavement engineering, highlighting WBO’s advantages for functional group restoration and balanced thermal rheological properties, supporting sustainable road development. Full article

With the continuous expansion of rare earth resource development, the large-scale accumulation of ionic rare earth tailings (IRETs) has exerted pressure on both environmental and resource management. Due to their inherent low reactivity, unstable composition, and potential environmental risks, their widespread engineering application faces many challenges. To achieve the resource utilization of this solid waste, scholars in recent years have conducted extensive research on their application in silicate materials. This study systematically reviews the existing research. Given that the trace rare earth oxides in IRETs exhibit excellent mineralization effects and that IRETs contain a significant amount of clay minerals, IRETs can be feasibly applied in the production of silicate materials, including clinker, tiles, ceramics, glass-ceramics, and geopolymers. The research findings aim to provide technical support and practical guidance for the large-scale resource utilization of IRETs, promoting their application in silicate material production. This study identifies the common issues found in the research and provides recommendations for the high-value and large-scale resource utilization of IRETs in the future. Full article

This paper reviews various emerging alternative SCMs derived from minerals and biomass sources, industrial byproducts, and underutilized waste streams. The paper compiles and evaluates physicochemical properties, reaction mechanisms in cementitious systems, resource availability, supply chain dynamics, technology readiness, the impact on concrete performance, and environmental and cost factors for each candidate SCM. Specifically, the review examines wood ash from bioenergy plants, volcanic and sedimentary natural pozzolans, and construction and demolition waste. This includes recycled concrete fines, asphalt plants’ rock dust (baghouse fines), aggregate production fines, and post-consumer waste, particularly municipal solid waste incinerator ash and wastewater sludge ash. Additionally, the paper explores innovative additives such as cellulose and chitin nanomaterials and calcium–silicate–hydrate nanoseeds to address challenges of slower strength development and rheological changes. The key contribution of this review is a multifactor framework for assessing alternative SCMs, emphasizing availability, supply chain, market readiness, and environmental performance, combined with an engineering performance review. Full article

High-dynamic airborne gravimetry faces critical challenges from platform-induced noise contamination. Conventional filtering methods exhibit inherent limitations in simultaneously achieving dynamic tracking capability and spectral fidelity. To overcome these constraints, this study proposes a Kalman–FIR fusion filtering (K-F) method, which is validated through engineering implementation on the GIPS-1A airborne gravimeter platform. The proposed framework employs a dual-stage strategy: (1) An adaptive state-space framework employing calibration coefficients (S_x, S_y, S_z) continuously estimates triaxial acceleration errors to compensate for gravity anomaly signals. This approach resolves aliasing artifacts induced by non-stationary noise while preserving low-frequency gravity components that are traditionally attenuated by conventional FIR filters. (2) A window-optimized FIR post-filter explicitly regulates cutoff frequencies to ensure spectral compatibility with downstream processing workflows, including terrain correction. Flight experiments demonstrate that the K-F method achieves a repeat-line internal consistency of 0.558 mGal at 0.01 Hz—a 65.3% accuracy improvement over standalone FIR filtering (1.606 mGal at 0.01 Hz). Concurrently, it enhances spatial resolution to 2.5 km (half-wavelength), enabling the recovery of data segments corrupted by airflow disturbances that were previously unusable. Implemented on the GIPS-1A system, K-F enables precision mineral exploration and establishes a noise-suppressed paradigm for extreme-dynamic gravimetry. Full article

The recycling of interconnects from solid oxide electrolyzer (SOEL) stacks is essential for closing material loops in green hydrogen systems. Since it is mostly made of high-quality stainless steel, remelting is the most practical recovery route, but it inevitably generates slag, where strategic elements like chromium (Cr) are retained. This study investigates the mineralogical and grain characteristics of slag from SOEL interconnect remelting, with an emphasis on Cr distribution and its recovery potential. A correlative approach was applied using X-ray diffraction (XRD), scanning electron microscopy-based mineral liberation Analysis (MLA), and X-ray computed tomography (XCT). Cr was primarily found in magnesiochromite Mg(Al,Cr)₂O₄ (~54 wt.% Cr), constituting only ~5 wt.% of the slag, while lower concentrations were also detected in monticellite and åkermanite. XCT revealed the macroscopic heterogeneity of the slag system, with metallic inclusions and pores concentrated near the metal–slag interface, indicating density-driven settling. Cr-rich spinels were fine-grained (x_50,2 ≈ 55 µm), irregular in shape, and partially intergrown, presenting challenges for mechanical liberation and physical recovery. These features, combined with their compositional selectivity, suggest that Cr-rich spinels are promising candidates for future Engineered Artificial Mineral (EnAM) strategies aimed at enhancing selective recovery from slag. Full article

Objectives: To prepare porous scaffolds combining hydrogel and hydroxycarbonateapatite, enriched with a promising therapeutic agent, gold nanoparticles, to improve bone regeneration. The fabrication procedure is conducted under mild conditions, without toxic or aggressive chemicals, at physiological pH, and low temperatures; Methods: Gold nanoparticles (15–20 nm), were obtained by the Turkevith method. The scaffolds were fabricated by the GELPOR3D method, which has demonstrated its ability to integrate thermal labile molecules, during the scaffold fabrication process. The role of these nanoparticles in promoting cell adhesion, proliferation, and mineralization processes in vitro has been studied using osteoprogenitor MC3T3-E1 cells; Results: The scaffold fabrication conditions, combined with the surface functionalization of the gold nanoparticles with poly(ethylene glycol), ensure their uniform distribution throughout the scaffold and facilitate their gradual release over 48 h in a physiological medium. A significant increase in the mean cell area and a significant decrease in the circularity index during the early stages of osteoblast differentiation are observed. These pieces of evidence suggest that adequate cell spreading could lead to enhanced proliferation and matrix deposition activity; Conclusions: Scaffolds containing these gold nanoparticles exhibited a marked improvement in adhesion, proliferation, and mineralization of preosteoblasts (MC3T3 cells) at the concentrations studied. The functionalization of the nanoparticles, along with the shaping procedure employed, is critical for their homogeneous dispersion throughout the scaffold and their progressive release. The findings confirm the crucial role of gold nanoparticles in the early stages of osteoblast differentiation, which is essential for the transition from premature osteoblasts to mature osteoblasts. Full article

The persistence of pharmaceutical pollutants such as ciprofloxacin (CIP) in aquatic environments represents a critical environmental threat due to their potential to induce antimicrobial resistance. Photocatalysis using TiO₂-based materials offers a promising solution for their mineralization; however, the limited visible-light response of TiO₂ and charge carrier recombination restricts its overall efficiency. In this study, Nb-doped TiO₂ nanoparticles were synthesized via the sol–gel method, incorporating Nb⁵⁺, ions into the TiO₂ lattice to modulate the structural and electronic properties of TiO₂ to enhance its photocatalytic performance for CIP degradation under UV and visible irradiation. Comprehensive structural, morphological, and optical analyses revealed that Nb incorporation stabilizes the anatase phase, reduces particle size (from 21.42 nm to 10.29 nm), and induces a slight band gap widening (from 2.85 to 2.87 eV) due to the Burstein–Moss effect. Despite this blue shift, Nb-TiO₂ exhibited significantly improved photocatalytic activity under visible light, achieving 86% CIP degradation with a reaction rate 16 times higher than that of undoped TiO₂. This enhancement was attributed to improved charge separation and higher hydroxyl radical (^•OH) generation, driven by excess conduction band electrons introduced by Nb doping. Density Functional Theory (DFT) calculations further elucidated the electronic structure modifications responsible for this behavior, offering molecular-level insights into Nb dopant-induced property tuning. These findings demonstrate how targeted doping strategies can engineer multifunctional nanomaterials with superior photocatalytic efficiencies, especially under visible light, highlighting the synergy between experimental design and theoretical modeling for environmental applications. Full article

Ore blending plays a critical role in ensuring feed consistency and optimizing downstream processes in the mining industry. Despite its importance, effective blending remains challenging due to ore variability and operational constraints. This review focuses exclusively on modern, data-driven blending methodologies, with particular emphasis on the application of data science and machine learning (ML) in predicting key process variables and supporting real-time decision-making. It discusses core challenges such as data quality, feature engineering, and model generalization, alongside enabling technologies including sensor integration, automation platforms, and real-time data acquisition systems. By consolidating the recent literature and highlighting emerging trends, this work outlines future directions for advancing intelligent blending systems and underscores the importance of standardized, high-quality data in the development of robust digital solutions for mineral processing. Full article

Microbially induced carbonate precipitation (MICP), as an eco-friendly biomineralization technology, has opened up an innovative path for the green and low-carbon development of the mining industry. Unlike conventional methods, its in situ solidification minimizes environmental disturbances and reduces carbon emissions during construction. This article reviews the research on MICP technology in various scenarios within the mining industry, summarizes the key factors influencing the application of MICP, and proposes a future research direction to fill the gap of the lack of systematic guidance for the application of MICP in this field. Specifically, it elaborates on the solidification mechanism of MICP and its current application in the solidification and storage of tailings, heavy metal immobilization, waste resource utilization, carbon sequestration, and field-scale deployment, establishing a technical foundation for broader implementation in the mining sector. Key influencing factors that affect the solidification effect of MICP are discussed, along with critical engineering challenges such as the attenuation of microbial activity and the low uniformity of calcium carbonate precipitation under extreme conditions. Proposed solutions include environmentally responsive self-healing technologies (the stimulus-responsive properties of the carriers extend the survival window of microorganisms), a one-phase low-pH injection method (when the pH = 5, the delay time for CaCO₃ to appear is 1.5 h), and the incorporation of auxiliary additives (the auxiliary additives provided more adsorption sites for microorganisms). Future research should focus on in situ real-time monitoring of systems integrated with deep learning, systematic mineralization evaluation standard system, and urea-free mineralization pathways under special conditions. Through interdisciplinary collaboration, MICP offers significant potential for integrated scientific and engineering solutions in mine waste solidification and sustainable resource utilization. Full article

Bone defects remain a significant clinical challenge, creating a severe need for advanced biomaterials for tissue regeneration. This study addresses this issue by developing 3D-printed composite hydrogels containing alginate, gelatine, and resorbable calcium phosphates (monetite and brushite) for bone tissue engineering. The scaffolds were fabricated using extrusion-based 3D printing and evaluated for their morphology, porosity, mechanical strength, swelling, degradation, and in vitro mineralization, while their cytocompatibility was assessed using LIVE/DEAD cell viability assays. The key findings demonstrate that calcium phosphate incorporation enhanced the mechanical stability by 15–25% compared to the controls, and mineral deposition increased significantly in the composite scaffolds. The developed hydrogels are bioactive and represent promising, customizable scaffolds for bone regeneration. These results support their further investigation as viable alternatives to traditional bone grafts for clinical bone tissue engineering applications. Full article

Due to the rapid advancement of technology, lithium carbonate has become a crucial raw material for battery storage applications. Brines remain the primary source, while lithium carbonate production from ores is limited. Therefore, expanding resources, identifying potential deposits, and characterizing existing sources are essential. Direct lithium detection via MLA is challenging due to its atomic number being below 6; however, it can be indirectly identified through lithium-bearing biotite. This study characterizes lithium-bearing biotite in nepheline syenite ore, considering biotite as the primary lithium source. Analytical methods included MLA, modal mineralogy, XRD, ICP-OES, XRF, SEM-BSE, and EDS. The ore contained 4% biotite, with a liberation degree exceeding 70% in particles finer than 500 µm. Biotite formed binary, ternary, and complex associations with K-feldspar, nepheline, and albite. Finer particle sizes increased biotite liberation while reducing associations; no binary biotite–nepheline associations were detected below 75 µm. EDS spectra confirmed biotite as the sole lithium-bearing mineral. Full article