Search Results (141)

Cement-based batteries (CBBs) are an emerging category of multifunctional materials that combine structural load-bearing capacity with integrated electrochemical energy storage, enabling the development of self-powered infrastructure. Although previous reviews have explored selected aspects of CBB technology, a comprehensive synthesis encompassing system architectures, material strategies, and performance metrics remains insufficient. In this review, CBB systems are categorized into two representative configurations: probe-type galvanic cells and layered monolithic structures. Their structural characteristics and electrochemical behaviors are critically compared. Strategies to enhance performance include improving ionic conductivity through alkaline pore solutions, facilitating electron transport using carbon-based conductive networks, and incorporating redox-active materials such as zinc–manganese dioxide and nickel–iron couples. Early CBB prototypes demonstrated limited energy densities due to high internal resistance and inefficient utilization of active components. Recent advancements in electrode architecture, including nickel-coated carbon fiber meshes and three-dimensional nickel foam scaffolds, have achieved stable rechargeability across multiple cycles with energy densities surpassing 11 Wh/m². These findings demonstrate the practical potential of CBBs for both energy storage and additional functionalities, such as strain sensing enabled by conductive cement matrices. This review establishes a critical basis for future development of CBBs as multifunctional structural components in infrastructure applications. Full article

Phonolite is a fine-grained, shallow extrusive rock rich in alkali minerals and containing iron/titanium-bearing minerals. This rock is widely used as a construction material for building exteriors due to its excellent abrasion resistance and insulation properties. However, during the cutting process, approximately 70% of the rock is discarded as tailing. So, this study aims to repurpose tailings from a phonolite cutting and sizing plant into a high-alkali ceramic raw mineral concentrate. To enable the use of phonolite tailings in ceramic manufacturing, it is necessary to remove coloring iron/titanium-bearing minerals, which negatively affect the final product. To achieve this removal, dry/wet magnetic separation processes, along with flotation, were employed both individually and in combination. The results demonstrated that using dry high-intensity magnetic separation (DHIMS) resulted in a concentrate with an Fe₂O₃ + TiO₂ grade of 0.95% and a removal efficiency of 85%. The wet high-intensity magnetic separation (WHIMS) process reduced the Fe₂O₃ + TiO₂ grade of the concentrate to 1.2%, with 70% removal efficiency. During flotation tests, both pH levels and collector concentration impacted the efficiency and Fe₂O₃ + TiO₂ grade (%) of the concentrate. The lowest Fe₂O₃ + TiO₂ grade of 1.65% was achieved at a pH level of 10 with a collector concentration of 2000 g/t. Flotation concentrates processed with DHIMS achieved a minimum Fe₂O₃ + TiO₂ grade of 0.90%, while those processed with WHIMS exhibited higher Fe₂O₃ + TiO₂ grades (>1.1%) and higher recovery rates (80%). Additionally, studies on flotation applied to WHIMS concentrates showed that collector concentration, pulp density, and conditioning time significantly influenced the Fe₂O₃ + TiO₂ grade of the final concentrate. Full article

The increasing demand for critical raw materials, such as antimony—a semimetal with strategic relevance in fire-retardant applications, electronic components, and national security—has made the identification of European sources essential for the European Union’s strategic autonomy. Remote sensing offers a valuable tool for detecting alteration minerals associated with subsurface gold and antimony deposits that reach the surface. However, the coarse spatial resolution of the most freely available satellite data remains a limiting factor. The PlanetScope satellite constellation presents a promising low-cost alternative for the academic community, providing 3 m spatial resolution and eight spectral bands. In this study, we evaluated PlanetScope’s capacity to detect Fe³⁺-bearing iron oxides—key indicators of hydrothermal alteration—by applying targeted band ratios (BRs) in northern Portugal. A comparative analysis was conducted to validate its performance using established BRs from Sentinel-2, ASTER, and Landsat 9. The results were assessed through relative comparison methods, enabling both quantitative and qualitative evaluation of the spectral similarity among sensors. Spatial patterns were analyzed, and points of interest were identified and subsequently validated through fieldwork. Our findings demonstrate that PlanetScope is a viable option for mineral exploration applications, capable of detecting iron oxide anomalies associated with alteration zones while offering finer spatial detail than most freely accessible satellites. Full article

The Karamaili Granite Belt (KGB) in the southern margin of the Eastern Junggar is the most important tin metallogenic belt in the southwestern Central Asian Orogenic Belt. The plutons in the western part have a close genetic relationship with tin mineralization. The zircon U-Pb ages of the Kamusite, Laoyaquan, and Beilekuduke plutons are 315.1 ± 3.4 Ma, 313.6 ± 2.9 Ma, and 316.5 ± 4.6 Ma, respectively. The plutons have high silica (SiO₂ = 75.53%–77.85%), potassium (K₂O = 4.43%–5.42%), and alkalis (K₂O + Na₂O = 8.17%–8.90%) contents and low ferroan (Fe₂O₃^T = 0.90%–1.48%), calcium, and magnesium contents and are classified as metaluminous–peraluminous, high-potassium, calc-alkaline iron granite. The rocks are enriched in Rb, Th, U, K, Pb, and Sn and strongly depleted in Ba, Sr, P, Eu, and Ti. They have strongly negative Eu anomalies (δEu = 0.01–0.05), 10,000 Ga/Al = 2.87–4.91 (>2.6), showing the geochemical characteristics of A-type granite. The zircon U/Pb ratios indicate that the above granites should be I- or A-type granite, which is generally formed under high-temperature (768–843 °C), low-pressure, and reducing magma conditions. The high Rb/Sr ratio (a mean of 48 > 1.2) and low K/Rb ratio (53.93–169.94) indicate that the tin-bearing plutons have undergone high differentiation. The positive whole-rock εNd(t) values (3.99–5.54) and the relatively young Nd T_2DM model ages (616–455 Ma) suggest the magma is derived from partially melted juvenile crust, and the underplating of basic magma containing mantle materials that affected the source area. The results indicate the KGB was formed in the tectonic transition period in the late Carboniferous subduction post-collision environment. Orogenic compression influenced the tin-bearing plutons in the western part of the KGB, forming highly differentiated and reduced I, A-type transition granite. An extensional environment affected the plutons in the eastern sections, creating A-type granite with dark enclaves that suggest magma mixing with little evidence of tin mineralization. Full article

The iron and steel industry generates large quantities of iron-bearing dust (IBD), contributing to resource inefficiency and environmental concerns. This study investigates heating methods and the use of organic solid waste, specifically waste tire carbon (WTC), as a reductant for the recovery of Fe from sintering machine tail dust (SMTD) and steelmaking gravity dust. The results indicate that the optimal reduction conditions occurred at 1000 °C, with a 2:1 ratio of SMTD to WTC, and 0% O₂ holding for 45 min. WTC is the best material, and heating methods affect it limitedly. The leaching behavior of seven metals was measured, showing an increase in the leaching of Ca and Al compared to the raw materials. The study shows that WTC provides a promising alternative reductant for IBD reduction, offering an energy-saving and low-carbon alternative to conventional fossil fuel injections in blast furnaces. The risk of Cr leaching should be paid attention to while enhancing Fe recovery. Full article

Conventional magnetorheological fluids (MRFs) exhibit a constrained shear strength that restricts their deployment in high-performance damping systems. This study introduces a dual-axis innovation strategy combining material science and device physics to fundamentally redefine MRF capabilities. We develop a hierarchical particle architecture through the controlled integration of micro/nano-sized carbonyl iron particles (CIPs), enhanced by polyethylene glycol/oleic acid surface engineering to optimize magnetic chain formation and interfacial bonding. The engineered MRF demonstrates a shear yield strength of 99.6 kPa at 0.757 T, surpassing conventional single-component MRFs by a significant margin. Integrated with a self-decoupling damper that isolates magnetic flux from mechanical motion, this synergistic design achieves exceptional force modulation: damping forces scale from 281.5 kN (5 mm stroke) to 300 kN (60 mm stroke), with current-regulated adjustability factors reaching 3.34. The system exhibits substantial improvements in both maximum damping force (93.9 kN enhancement) and energy dissipation efficiency compared to standard MRF dampers. Through co-optimization of the particle architecture and magnetic circuit design, this work establishes new performance benchmarks for smart fluid technology. The achieved force capacity and dynamic response characteristics directly address critical challenges in seismic engineering and industrial vibration control, where extreme load-bearing requirements demand simultaneous high strength and tunable damping capabilities. Full article

The Sanandaj–Sirjan Zone and Zagros Fold–Thrust Belt in Iran host numerous Mediterranean-type karst bauxite deposits; however, their formation mechanisms and critical raw material potential remain ambiguous. This study combines mineralogical and geochemical analyses to explore (1) the formation of authigenic minerals, (2) the role of microbial organic processes in Fe cycling, and (3) the assessment of their critical raw materials potential. Mineralogical analyses of the Late Cretaceous Daresard and Middle–Late Permian Yakshawa bauxites reveal distinct horizons reflecting their genetic conditions: Yakshawa exhibits a vertical weathering sequence (clay-rich base → ferruginous oolites → nodular massive bauxite → bleached cap), while Daresard shows karst-controlled profiles (breccia → oolitic-pisolitic ore → deferrified boehmite). Authigenic illite forms via isochemical reactions involving kaolinite and K-feldspar dissolution. Scanning electron microscopy evidence demonstrates illite replacing kaolinite with burial depth enhancing crystallinity. Diaspore forms through both gibbsite transformation and direct precipitation from aluminum-rich solutions under surface conditions in reducing microbial karst environments, typically associated with pyrite, anatase, and fluorocarbonates under neutral–weakly alkaline conditions. Redox-controlled Fe-Al fractionation governs bauxite horizon development: (1) microbial sulfate reduction facilitates Fe³⁺ → Fe²⁺ reduction under anoxic conditions, forming Fe-rich horizons, while (2) oxidative weathering (↑Eh, ↓moisture) promotes Al-hydroxide/clay enrichment in upper profiles, evidenced by progressive total organic carbon depletion (0.57 → 0.08%). This biotic–abiotic coupling ultimately generates stratified, high-grade bauxite. Finally, both the Yakshawa and Daresard karst bauxite ores are enriched in critical raw materials. It is worth noting that the overall enrichment appears to be mostly driven by the processes that led to the formation of the ores and not by the chemical features of the parent rocks. Divergent bauxitization pathways and early diagenetic processes—controlled by paleoclimatic fluctuations, redox shifts, and organic matter decay—govern critical raw material distributions, unlike typical Mediterranean-type deposits where parent rock composition dominates critical raw material partitioning. Full article

The quality of strong-flavor baijiu largely depends on the physicochemical properties and prokaryotic microbial activities of pit mud. However, the impact of the iron-bearing minerals in pit mud on its prokaryotic microbial communities remains unknown. This study examined the differences in the prokaryotic communities between 2-year, 40-year, and 100-year pit mud and yellow soil (the raw material for pit mud), as well as the impacts of environmental factors, particularly iron-bearing minerals, on the structure and diversity of these prokaryotic communities. The results indicated that there were significant differences in the composition of prokaryotic microorganisms between yellow soil and pit mud. As the fermentation pit aged, the relative abundance of dominant fermentation bacteria (including Petrimonas, Syntrophomonas, Clostridium, etc.) and hydrogenotrophic methanogens in the pit mud increased. The relative abundance of Lactobacillus in the 2-year pit mud was low (0.33%). Under laboratory conditions, goethite (a typical crystalline iron mineral, denoted as Fe_c) reduced the physiological and metabolic activity of Lacticaseibacillus paracasei JN01 in a concentration-dependent manner. The results of the physicochemical analysis showed that the contents of total iron (TFe) and Fe_c significantly decreased, while the contents of Fe(II) and amorphous iron (hydr)oxides (Fe_o) significantly increased with an increasing fermentation pit age. TFe and Fe_c were significantly negatively correlated with both the Chao1 and Shannon indexes and functional microorganisms such as Clostridium_sensu_stricto_12, Sedimentibacter, and hydrogenotrophic methanogens. The current results contribute to our understanding of the aging process of pit mud from the perspective of the interaction between iron-bearing minerals and prokaryotic microorganisms. Full article

The particle size of raw materials is crucial for clinker formation, ultimately affecting cement performance. However, the specific effects of the fineness of individual raw materials on clinker burnability remain insufficiently understood. In this study, the fineness of limestone, shale, and iron-bearing materials was systematically varied to explore its influence on raw meal burnability and the resulting cement properties. Raw materials were prepared with controlled residue levels (5–20%) retained on an 80 μm sieve. Their impact was evaluated based on free lime content (f-CaO), clinker phase composition, cement strength development, and hydration behavior. Among the variables studied, limestone fineness was found to be the predominant factor affecting f-CaO levels, confirming its dominant role in governing clinker burnability. In contrast, fineness adjustments of aluminosilicate and iron-bearing components produced comparatively minor effects. Despite variations in raw meal fineness, clinkers produced with sieve residues between 10% and 15% exhibited consistent phase compositions, primarily comprising tricalcium silicate (C₃S), dicalcium silicate (C₂S), tricalcium aluminate (C₃A), and tetracalcium aluminoferrite (C₄AF). Furthermore, cement pastes derived from these clinkers demonstrated similar setting times, mechanical strengths, and hydration product assemblages. These results highlight the robustness of cement performance with respect to moderate variations in raw material fineness, particularly when limestone fineness is adequately controlled. Full article

In zooarchaeological research, animal bone fractures can result from various processes including slaughtering, dismemberment, marrow/grease extraction, craft processing, carnivore gnawing/trampling, sediment compression, bioturbation, and recovery bias. These fractures are further influenced by bone freshness/dryness and environmental temperature. The animal bones analysed in this study, excavated from Han dynasty tombs in the Xinxiang Plain New District, China, represent ritual offerings. These specimens exhibit distinct truncation features—chop surfaces, rough planes, and fracture traces—created by ancient iron tools for culinary purposes such as stewing preparation or consumption facilitation. These characteristics differ significantly, from the V-shaped butchery marks produced by stone/bronze tools and fracture patterns from marrow/grease extraction to post-depositional breakage formed during burial processes. In this study, steel tools were employed in the rocking slicing and rolling slicing of animal bones, complemented by techniques such as breaking to sever bone shafts. Subsequently, the marks on the cross-sections were observed using a stereomicroscope, and the results were compared and analysed with the materials from Han dynasty tombs unearthed at Xinxiang city, Henan Province. From the comparison between experimental observation results and archaeological materials, it is evident that the fine processing of meat-bearing bone materials mainly involved the use of rocking and rolling slicing methods. The cross-sections of the slices revealed shearing surfaces, rough patches, bone splinters, and sliced ends. The shearing surfaces in particular exhibited numerous visible trace characteristics, with the types and quantities of these traces varying with different cutting tools. This study holds significant reference value for exploring cutting tools and techniques in antiquity. Full article

Phytostabilization of metals involves the inactivation of metals in the soil through the use of various materials as soil amendments, which reduces the bioavailability of metals, and then the introduction of vegetation. There are limited data comparing the effectiveness of different phytostabilization amendments under the same soil and environmental conditions. Therefore, the aim of this research was to compare the effectiveness of a range of soil amendments on reducing the extractability of metals, metal uptake by plants, microbial activity in soil and nutrient availability to plants. Eight materials potentially limiting metal availability were used in a pot experiment: two composts (CG, CM), municipal biosolids (SB), bentonite (BEN), phosphorus fertilizer (PF), amorphous iron oxide (FE), waste rock material (WR), calcium carbonate (LM); and these materials were compared with typical fertilization (NPK) and an untreated soil as the control (CTL). The following trace metal-contaminated soils were used in the pot experiment: soil taken from the area of strong dust fall from the zinc and lead smelter (soil P); soil taken from an outcrop of ore-bearing rocks near a smelter waste heap (soil H); soil artificially polluted through smelter dust spill in the 1990s (soil S). In general, the greatest yields of plants (oat and white mustard) were recorded for compost-treated soils. Changes in the solubility of zinc (Zn) and cadmium (Cd) after the application of various amendments largely reflected changes in soil pH. Biosolids caused a significant increase in extractable Zn and Cd, which was related to the decrease in soil pH, while a significant reduction in Cd extractability was observed across soils after the application of both composts, especially the compost characterized by alkaline pH. Interestingly, low extractability of Cd in the soil with the addition of another compost was observed, despite the pH decrease, as compared to the control pots. This fact proves the high sorption capacity of the compost towards Cd. The microbiological analyses revealed the highly beneficial effect of composts for dehydrogenases and nitrification activities, and for soil respiration, whereas soil amendment with iron oxide caused an increase in respiration activity across soils. Full article

Silicon nitride (Si₃N₄) is used for high-speed rotating bearings in machine tools, aircraft, and turbo pumps due to its excellent material properties such as high-temperature strength, hardness, and fracture toughness. Grinding with fixed abrasives enables high shape accuracy and high efficiency in machining brittle materials. However, it is difficult to completely remove surface damage, which limits its use in products requiring a nano surface. These defects also result in reduced reliability and shortened lifespan. Magnetic-assisted polishing (MAP) is a technology that can achieve a fine surface by using a mixture of iron powder and abrasives, but it requires a lot of time due to the low material removal rate (MRR). Therefore, this study developed a hybrid processing technology using a metal-bonded grinding wheel and a slurry with hard abrasives for the high precision of silicon nitride ceramic ball bearings. Experiments were conducted in order to compare and analyze the surface roughness and material removal rate. Through MAP, using a grinding wheel with low grit (#325), high-efficiency machining performance was confirmed with a maximum material removal rate of 1.193 mg/min. In MAP, using a grinding wheel with high grit (#2000), a nano-level surface roughness of 6.5 nm Ra was achieved. Full article

The increased consumption of strategic metals has led to the necessity to search for new and non-traditional sources of mineral raw materials. All this has resulted in the necessity to develop and justify new technological solutions for the integrated recovery of strategic metals and the associated production of high-purity carbon materials. The purpose of this work was to substantiate the possibility of obtaining high-purity shungite carbon materials and metal-bearing concentrate containing valuable metals from shungite rocks using high-gradient magnetic separation and flotation with the use of an apolar collector emulsion in a frother solution. The conducted investigations using a complex of analysis methods allowed us to justify the obtaining of a metal-bearing concentrate containing iron, titanium, copper and zirconium and carbon material of high purity. By using high-gradient magnetic separation, we obtained a metal-bearing concentrate with a yield of 17.35% and a total metal content of 63.61% broken down as follows: Fe₂O₃ recovery of 87.66%, TiO₂ recovery of 56.03%, CuO recovery of 72.52% and ZrO₂ recovery of 54.42%. By using flotation, we obtained a shungite carbon concentrate with a yield of 31.41%, made of 88.15% carbon with a content and recovery of 88.09% and a sulphur content of 0.084%. The conducted studies showed the possibility of using classical beneficiation operations in the processing of non-traditional mineral raw materials to obtain commercial products. Full article

The Guangyuan kiln, located in the Sichuan Province, Southwest China during the Song Dynasty (960–1279 A.D.), is renowned for its high-temperature iron-series glazed wares, including pure black glazed ware, hare’s fur glazed ware, glossy brown glazed ware, and matte brown glazed ware. To elucidate the raw materials, processing techniques, and coloration mechanisms of these wares, multiple analytical experiments were employed to investigate chemical composition, microstructure, and the phase of Fe-bearing minerals. We found that glossy brown glazed ware has the highest Fe₂O₃ content in the glaze (7.67 wt% on average), while pure black glazed ware exhibits the lowest (4.84 wt% on average). Higher Fe₂O₃ content leads to more iron for Fe-bearing mineral crystallization and larger ε-Fe₂O₃ precipitation. Based on microscopic observations, pure black glazed ware has numerous 100–250 nm crystalline grains, while hare’s fur glaze ware features dendritic crystal flowers (200–400 nm), which exhibited liquid-liquid phase separation within the glaze, suggesting localized phase separation inducing iron oxide crystallization. Glossy brown glazed ware contains well-developed ε-Fe₂O₃ crystals (25 µm), and matte brown glazed ware, with the highest CaO and total flux, has acicular anorthite crystals alongside ε-Fe₂O₃ crystals. In summary, the decorative effect of four different types of iron-series glazed wares is determined by their chemical composition, phase composition, and microscopic structure. The findings offer valuable insights for the study of ancient iron-glazed ware. Full article

This review explores the advancements in additive manufacturing (AM) of biodegradable iron (Fe) and zinc (Zn) alloys, focusing on their potential for medical implants, particularly in vascular and bone applications. Fe alloys are noted for their superior mechanical properties and biocompatibility but exhibit a slow corrosion rate, limiting their biodegradability. Strategies such as alloying with manganese (Mn) and optimizing microstructure via laser powder bed fusion (LPBF) have been employed to increase Fe’s corrosion rate and mechanical performance. Zn alloys, characterized by moderate biodegradation rates and biocompatible corrosion products, address the limitations of Fe, though their mechanical properties require improvement through alloying and microstructural refinement. LPBF has enabled the fabrication of dense and porous structures for both materials, with energy density optimization playing a critical role in achieving defect-free parts. Fe alloys exhibit higher strength and hardness, while Zn alloys offer better corrosion control and biocompatibility. In vitro and in vivo studies demonstrate promising outcomes for both materials, with Fe alloys excelling in load-bearing applications and Zn alloys in controlled degradation and vascular applications. Despite these advancements, challenges such as localized corrosion, cytotoxicity, and long-term performance require further investigation to fully harness the potential of AM-fabricated Fe and Zn biodegradable implants. Full article