Search Results (155)

Osteoporosis is a major public health concern, particularly among postmenopausal women. Environmental exposure to metals has been proposed as a potential contributor to osteoporosis, but human data remain limited and inconsistent. This study investigated changes in urinary concentrations of 20 metal(loid)s in patients with osteoporosis, as well as the association of these elements with bone mineral density (BMD), in a cohort of 380 postmenopausal women aged 50–70 years from Cascavel, Paraná, Brazil. Demographic, lifestyle, and clinical data were collected, and urinary concentrations of aluminum (Al), barium (Ba), cadmium (Cd), cobalt (Co), cesium (Cs), copper (Cu), mercury (Hg), lithium (Li), manganese (Mn), molybdenum (Mo), nickel (Ni), lead (Pb), rubidium (Rb), antimony (Sb), selenium (Se), tin (Sn), strontium (Sr), thallium (Tl), uranium (U), and zinc (Zn) were measured by inductively coupled plasma mass spectrometry. BMD was assessed at the lumbar spine, femoral neck, and total hip using dual-energy X-ray absorptiometry. Osteoporosis was diagnosed in 73 participants (19.2%). Osteoporotic women had significantly higher urinary concentrations of Cd, Mn, Pb, Sb, Sn, and Zn (p < 0.05). Statistically significant negative correlations were observed between BMD and urinary concentrations of Al, Cd, Hg, Mn, Sb, and U. After adjustment for confounders, elevated urinary concentrations of Cd, Mn, Pb, and Sb remained independently and significantly associated with higher odds of osteoporosis, with Cd (aOR = 1.495; p = 0.026) and Sb (aOR = 2.059; p = 0.030) showing the strongest associations. In addition, women with urinary concentrations above the 90th percentile for both Cd and Sb had a significantly higher prevalence of osteoporosis compared to those with lower levels (44.4% vs. 18.0%; p = 0.011). Longitudinal studies are needed to confirm causality and inform prevention strategies. Full article

Eocene magmatic systems contemporaneous with world-class Carlin-type Au deposits in Nevada (USA) have been proposed by some researchers as a key ingredient for Au mineralization, though evidence conclusively demonstrating their genetic relationship remains tenuous. This study provides the first direct evidence of the pre-eruptive metal budget of volatile- and metal-charged silicic magmas coincident in time (~41 to 34 Ma) and space (within 5 km) with Carlin-type Au deposits. We characterize the pre-eruptive metal fingerprints of these diverse magmatic systems to assess their potential as sources of metals for Carlin-type Au mineralization. Metal abundances from quartz-hosted melt inclusions (Au, Te, Ag, Sb, Tl, Mo, W, Sn, As, Pb, Co, Cu, Ni, and Zn) characterized in situ by SHRIMP-RG and LA-ICP-MS represent our best (and only) estimates for the pre-eruptive metal budget in these systems. Median metal concentrations are generally within one order of magnitude of average upper crust and average continental rhyolite values. But there are two notable exceptions, with median Au contents extending >1 order of magnitude higher than average upper crust and median Cu contents ranging >1 order of magnitude lower than upper crust. Despite this, melts contain lower Au/Cu (<0.1), Au/Ag (<5), and Au/Tl (<0.3) than most ore-grade Carlin-type rock samples and quartz-hosted fluid inclusions, regardless of their age and timing relative to nearby Carlin-type Au mineralization. The metal fingerprints of these magmatic systems, defined both by traditional and multivariate compositional data analysis techniques, are distinct from one another. Yet none are particularly specialized, e.g., high Au/Cu, in terms of being ideal ingredients as postulated by magmatic models for Carlin-type Au mineralization. Magmatic Au contents do not appear to be correlated with rhyolite “flavors” in the way that Cu, Sn, and Nb contents are. Fluid/melt partitioning modeling and magma volume estimates support the idea that a diverse array of non-specialized silicic magmas could feasibly contribute some or potentially all of the Au, Ag, and Cu in Carlin-type systems. The compositional diversity among contemporaneous magmatic systems could possibly contribute to some of the diversity observed across Carlin-type Au districts in Nevada. Full article

Enhancing the durability and tribological performance of babbitt alloys is critical for high-stress applications in automotive, marine, and industrial machinery. The present study explores the electrodeposition of chromium coatings on SnSb11Cu6 alloys to improve their microstructural, mechanical, and tribological properties. The coatings were applied through an electrolytic process and systematically characterized using scanning electron microscopy and energy-dispersive X-ray spectroscopy to evaluate their morphology, composition, and wear performance. The chromium coating exhibited a uniform thickness of 20.2 µm and significantly improved the surface hardness to 715.2 HV, far surpassing the matrix and intermetallic phases of the uncoated alloy. Tribological testing under dry sliding conditions demonstrated a 44% reduction in the coefficient of friction (COF) and a 54% decrease in mass wear for the coated alloy, highlighting the protective role of the chromium layer against abrasive and adhesive wear. To further analyze the frictional behavior, a deep learning model based on a one-dimensional convolutional neural network was employed to predict COF trends over time, achieving excellent accuracy with R² values of 0.9971 for validation and 0.9968 for testing. Feature importance analysis identified coating hardness as the most critical factor influencing COF and wear resistance, followed by matrix hardness near the coating. These findings underscore the effectiveness of chromium coatings in mitigating wear damage and improving the operational lifespan of SnSb11Cu6 alloys in high-stress applications. This study not only advances the understanding of chromium coatings for babbitt materials but also demonstrates the potential of machine learning in optimizing tribological performance. Full article

The Jiepailing deposit in southern Hunan is a typical large to super-large polymetallic tin deposit enriched in beryllium and other rare metals. To enhance the understanding of the mineralization processes of the Jiepailing deposit, detailed mineralogical, in situ geochemical, and sulfur isotopic analyses were conducted on pyrite closely associated with tin–polymetallic mineralization. Five types of pyrite have been identified in the deposit: (1) euhedral to subhedral medium- to coarse-grained pyrite (PyI) in tungsten–tin ore; anhedral fine-grained pyrite (PyII) in tin polymetallic–fluorite ore; anhedral fine-grained or aggregate pyrite (PyIII) in lead–zinc ore; euhedral to subhedral coarse-grained pyrite (PyIV) in beryllium–fluorite mineralization; and subhedral to anhedral fine-grained pyrite (PyV) in carbonate veinlets developed in the wall rock. Backscattered electron imaging indicates consistent structural features across the five types of pyrite. In situ trace element analysis reveals differences in trace element concentrations among the pyrite types. PyI is relatively enriched in Sn, Cu, and Co. In contrast, PyIII is enriched in Pb, Zn, Sn, and Ti, while PyIV and PyV are enriched in Ag and Sb. PyI has a Co/Ni ratio more than 1, while the Co/Ni ratios in the other four types of pyrite are less than 1. LA-MC-ICP-MS in situ sulfur isotope analysis shows δ³⁴S values ranging from 2.5‰ to 5.8‰ (average 4.3‰, PyI), 2.5‰ to 5.8‰ (average 4.3‰, PyII), −7.6‰ to 9.5‰ (average 3.9‰, PyIII), −3.7‰ to 10.6‰ (average 3.6‰, PyIV), and 6.8‰ to 14.1‰ (average 9.2‰, PyV). Based on previous studies, regional geological background, deposit characteristics, and the in situ trace element and sulfur isotope compositions of pyrite, it is inferred that the various ore bodies in the Jiepailing deposit are products of Late Cretaceous magmatic–hydrothermal activity. The early ore-forming fluid originated from magmatic sources and during the migration into the wall rock and shallow formations, mixed with fluids primarily derived from atmospheric precipitation. Temperature, pressure, and composition changed of the ore-forming fluid which carried a large amount of substances, leading to tungsten–tin, tin polymetallic–fluorite, lead–zinc, and beryllium–fluorite mineralization, followed by carbonation during the late-stage mineralization. Full article

This paper evaluates the possibility of analyzing the composition of high-quality copper scrap with X-ray fluorescence spectrometry (XRF) instead of electrogravimetry combined with flame atomic absorption spectroscopy (EG+FAAS) method. The evaluation of the methods was performed on three real copper scraps, the composition of which were estimated in average samples taken after re-melting. Traceability of XRF results was ensured by the use of new certified reference materials (CRMs) dedicated to copper scrap analysis. The copper content results obtained by XRF were characterized by high agreement with the reference results obtained by EG+FAAS method. The estimated expanded uncertainty for Cu of both methods was 0.23%. In addition to significant time savings without compromising accuracy, the XRF method additionally provided information on the content of 12 other elements, such as Sn, Zn, Co, Cd, Sb, Ni, Fe, Pb, Bi, Ag, Al, and P. This may make the XRF method attractive compared to the commonly used EG+FAAS method. Full article

A comparative elemental analysis of espresso coffee from Poland and Portugal was carried out. Using an ICP-MS analytical procedure, samples collected from public cafes in Poland and Portugal (n = 60 and n = 44, respectively) were studied for their macromineral and trace element content. To evaluate the contribution of water to the final composition of the beverage, paired samples (i.e., collected from the same locations) of drinking water were also analysed. The mineral profile of the coffee espresso samples was quite similar: Mg > P > Ca > Rb > Mn > B > Zn > Cu > Sr > Ba > Ni > Pb > Cs > Mo > Sn > Cd > Sb > Tl for samples from Poland and Mg > P > Ca > Rb > B > Mn > Zn > Sr > Cu > Ni > Ba > Cs > Pb > Mo > Sn > Sb > Cd > Tl for samples from Portugal. For most of the elements, the espresso samples showed much higher levels than the water used in its preparation. The two most notable exceptions were Ca and Sr, where the elements present in the coffee came mainly from the water. The contribution of coffee espressos to the daily intake of essential elements seems to be reduced. Other non-essential elements like Ni (median = 81.0 µg/L and 86.8 µg/L for Polish and Portuguese espresso, respectively) and Pb (median = 14.3 µg/L and 4.43 µg/L, respectively) were observed in significant amounts in the coffee espresso samples analysed in this study. These elements have been shown to leach from coffee machines in other studies. More studies are necessary to confirm these results. Full article

The behavior of impurities in cast copper was investigated to simulate production with increased utilization of secondary sources within the framework of a circular economy. The incorporation of impurities, particularly Ni, Sn, and Sb, from recycled Cu may significantly impact the electrorefining process. In this study, commercial anodes were doped with Ni, Sn, and Sb concentrations of 2500–6500 g/t, 300–900 g/t, and 450–950 g/t, respectively. Anode concentrations of Pb and Bi were maintained at 1000 g/t and 350 g/t, respectively. As concentrations were examined at two levels, 860 or 1700 g/t, depending on the commercial anode used to create the doped samples. Electron microscopy with microprobe analysis revealed that the commercial anodes contained three predominant phases: Cu₂O, (Cu,Ag)₂(Se,Te), and a complex oxide phase of Cu, Pb, As, Sb, and/or Bi. Ni, the main impurity, primarily accumulated within the Cu grains, while Sn and Sb tended to form oxidized inclusions. The distribution of Ni in Cu grains was ca. 20% lower in the anodes doped at higher Ni concentrations due to the formation of nickel-bearing inclusions, such as Kupferglimmer and NiO. The doped anodes showed lower quantities of Cu₂O inclusions than the commercial anodes due to the preferential formation of oxides with other impurities, including SnO₂. These findings highlight potential challenges for Cu electrorefining in a circular economy, as Ni, Sb, and Sn may impact the deportment of these impurities to slimes or electrolyte and may cause copper depletion in the refining electrolyte. Full article

Multivariate and statistical tool advancements help to assess potential pollution threats, their geochemical distribution, and the competition between natural and anthropogenic influences, particularly on sediment contamination with potentially toxic metals (PTMs). For this, riverine sediments from 25 locations along urban banksides of the River Ravi, Pakistan, were collected and analyzed to explore the distribution, pollution, ecological, and toxicity risk indices of PTMs like Al, As, Cd, Co, Cr, Cu, Fe, Hg, Mn, Ni, Pb, Sb, Sn, Sr, V, and Zn using Inductively Coupled Plasma–Optical Emission Spectrometry (ICP-OES) technique. Additionally, techniques such as X-ray Diffraction (XRD) and Scanning Electron Microscopy–Energy Dispersive X-ray Spectroscopy (SEM-EDS) were employed to investigate the mineralogical and morphological aspects. The results indicated that mean concentrations (mg kg⁻¹) of Cd (2.37), Cr (128), Hg (16.6), Pb (26.6), and Sb (2.44) were significantly higher than reference values given for upper continental crust (UCC) and world soil average (WSA), posing potential threats. Furthermore, the geochemical pollution indices showed that sediments were moderately polluted with Cd (I_geo = 2.37, EF = 12.1, and CF = 7.89) and extremely polluted with Hg (I_geo = 4.54, EF = 63.2, and CF = 41.41). Ecological and toxicity risks were calculated to be extremely high, using respective models, predominantly due to Hg (Er_i = 1656 and ITRI = 91.6). SEM-EDS illustrated the small extent of anthropogenic particles having predominant concentrations of Zn, Fe, Pb, and Sr. Multivariate statistical analyses revealed significant associations between the concentrations of PTMs and the sampling locations, highlighting the anthropogenic contributions linked to local land-use characteristics. The present study concludes that River Ravi sediments exhibit moderate levels of Cd and extreme pollution by Hg, both of which contribute highly to extreme ecological and toxicity risks, influenced by both natural and anthropogenic contributions. Full article

In this paper, the ultrasonic vibration treatment (UVT) technique was used to prepare a SnSbCu11-6 alloy semi-solid slurry, and the effects of ultrasonic power on its microstructure size, distribution and properties were studied. The results show that the UVT technique significantly refines the Cu6Sn5 phase and SnSb phase and improves their distribution uniformity. Interestingly, the second SnSb phase is also well refined to nearly 100 °C below the melting point; furthermore, the morphology is transformed from coarse petal-like to fine regular cubic, and the average grain size is refined to 48.8 ± 8.8 μm. The alloy’s comprehensive properties are best when the ultrasonic power is 1200 W. The yield strength, tensile strength, elongation and microhardness reach 60.6 MPa, 70.3 MPa, 4.9% and 27.4 HV, respectively, which represent increases of 4.7%, 6.0%, 113% and 23.4%, respectively, compared with conventional liquid casting. This may be attributed to the grain size refinement and distribution uniformity enhancement of the Cu6Sn5 phase and the SnSb phase. This work provides a feasible and effective method for the preparation of high-performance tin-based babbitt alloys by UVT technology. Full article

Discovered within the North Himalayan Metallogenic Belt (NHMB), the Zhaxikang Pb–Zn–Ag–Sb deposit stands as the sole super-large scale ore deposit in the region. This deposit holds significant quantities of Pb and Zn (2.066 million tons at 6.38% average grade), Ag (2661 tons at an average of 101.64 g/t), and Sb (0.235 million tons at 1.14% average grade), making it one of China’s foremost Sb–polymetallic deposits. Stibnite represents the main carrier of Sb in this deposit and has been of great attention since its initial discovery. However, the trace element composition of stibnite in the Zhaxikang deposit has not yet been determined. This study carried out an analysis of the distribution patterns and substitution processes of trace elements within stibnite gathered from the Zhaxikang deposit, aiming to provide crucial information on ore-forming processes. Utilizing high-precision laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS), we discovered that the studied stibnite is notably enriched in arsenic (~100 ppm) and lead (~10 ppm). Furthermore, the notably consistent time-resolved profiles suggest that elements such as Fe, Cu, As, In, Sn, Hg, and Pb predominantly exist as solid solutions within stibnite. Consequently, it is probable that the enrichment of Cu, Pb, and Sn in stibnite is due to isomorphic substitution reactions, including 3Pb²⁺↔2Sb³⁺, Cu⁺ + Pb²⁺↔Sb³⁺, and In³⁺ + Sn³⁺↔2Sb³⁺. Apart from that, Mn, Pb, and Hg with the spiky signals indicate their existence within stibnite as micro-inclusions. Overall, we found that the trace element substitutions in stibnite from the Zhaxikang Pb–Zn–Ag–Sb deposit are complicated. Incorporations of trace elements such as Pb, Cu, and In into stibnite are largely influenced by a variety of factors. The simple lattice structure and constant trace elements in studied stibnite indicate a low-temperature hydrothermal system and a relatively stable process for stibnite formation. Full article

The newly delineated Xipu Dome, located in the central North Himalayan Gneiss Dome (NHGD), exhibits a significant spatiotemporal relationship with Himalayan polymetallic mineralization. Based on field geological surveys and geochronological analyses, this study provides a comprehensive assessment of the lithological assemblage, tectonic deformation, and metallogenic processes of the Xipu Dome. The findings reveal a three-tiered structure: the core consists of early Paleozoic granitic gneiss (523 Ma) and Miocene leucogranite (13.5 Ma), overlain by a cover of low-grade metamorphic or unmetamorphosed sedimentary rocks, and a detachment zone composed of heavily deformed schists and phyllites. The Xipu Dome underwent three phases of tectonic deformation: a southward thrust caused by continental collision, northward extensional activity driven by the South Tibet Detachment System (STDS), and gravitational collapse and downslope sliding following the emplacement of the dome. Two types of mineralization were identified: structural hydrothermal Au-Cu polymetallic deposits related to detachment and skarn-type Cu-Ag polymetallic deposits associated with leucogranite intrusion. This study enhances the understanding of the spatial distribution and metallogenic potential within the Himalayan Be-Sn rare metal-Pb-Zn-Sb-Au belt, offering a valuable direction for strategic mineral exploration in the Tethyan Himalaya (TH). Full article

Unlike municipal solid waste bottom ash (MSWBA), fly ash (MSWFA) is landfilled due to its toxicity. However, MSWFA may also be a source of elements. Ash samples collected from a Portuguese MSW incinerator from different locations and over six months were analyzed. Their geochemical composition was normalized to the upper continental crust (UCC) and compared since metal enrichment may be used as an indicator for potential recovery. The potential recovery economic viability was also assessed for metals K, Sb, Cu, Pb, and Zn, considering the ore cut-off grade and minimum industrial grade (MIG) from Chinese geological and mineral industry standards. Compared to the global samples, only the Baghouse 1 FA size fraction’s coarse fraction showed a slight enrichment (1- to 5-fold) in Bi, Nb, and Zr. After wet sieving, most trace elements were enriched in all fractions, but Sb, Bi, Pb, Zn, Ag, As, Cd, Sn, Se, and Hg were depleted in the coarse fractions and enriched in the fine ones. For Baghouse 1 samples collected over 6 months, the normalization to the UCC showed enrichment of Zn and Pb between 10× and 50×, Zr, Cu, In, and Se between 50× and 100×, and Ag, Mn, Cd, Sb, and Bi at more than 100×. Over six months, the Baghouse 1 FA soluble fraction ranged between 21 wt.% and 30 wt.%, and its precipitates comprised 27% CaO, 6% Na₂O, and 9% K₂O. The K concentration in the MSWFA was above the cut-off and the MIG, and K could be concentrated in precipitates via simple washing. Full article

The aim of the present study was to evaluate the contamination state of the surface soil from 10 parks from Galati, Romania, and the health hazards of the soil. The soil samples, collected in each site from the playing ground and from the edge of the park, were analyzed by using combined Wavelength- (WDXRF) and Energy-Dispersive (EDXRF) X-ray fluorescence techniques. A total number of 27 chemical elements (Ag, Al, As, Ba, Ca, Cd, Cr, Co, Cu, Fe, Hg, K, Mg, Mn, Na, Ni, P, Pb, Rb, Sb, Sc, Sn, Sr, Ti, V, Zn and Zr) were quantified in the urban soils, and the results were compared to the normal and alert values from Romanian legislation for toxic trace elements, as well as with European and world average values of element concentrations. The mineralogical analyses were performed by Scanning Electron Microscopy with Energy-Dispersive X-ray Analysis (SEM-EDX) and the Attenuated Total Reflectance–Fourier Transform Infrared technique (ATR-FTIR). To assess the soil contamination and the impact on human health of the presence of potential toxic elements and heavy metals in the soil, a series of pollution and health risk indices were used. All the results indicated an unpolluted to moderately polluted soil. The soil samples collected from the edge of the parks presented higher values for the specific pollutants, which originated from heavy traffic, such as Cu, Cr, Zn and Pb. The non-carcinogenic and carcinogenic risk to children was assessed using estimated daily intake (EDI) in relation to the pathways whereby pollutants can enter the human body, such as ingestion, dermal contact, inhalation and vaporization. Using the obtained values for EDI, the hazard quotient and hazard index were determined, which strengthen the formerly issued presumption that soil pollution is moderate and, by itself, does not present any threat to children’s health. Full article

A Babbitt alloy SnSb11Cu6 with 0–2.0 wt.% Co was synthesized using the induction melting process. This study examined the effect of cobalt (Co) on the microstructure, tensile properties, compressive properties, Brinell hardness, and wear properties of SnSb11Cu6 using optical microscopy (OM), scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS), X-ray diffraction (XRD), a universal tensile testing machine, a Brinell hardness tester, and a wear testing machine. The results indicate that the optimal quantity of Co can enhance the microstructure of the Babbitt alloy and promote microstructure uniformity, with presence of Co₃Sn₂ in the matrix. With the increase in Co content, the tensile and compressive strength of the Babbitt alloy first increased and then decreased, and the Brinell hardness gradually increased with the increase in Co content. The presence of trace Co has a minimal effect on the dry friction coefficient of the Babbitt alloy. When the Co content exceeds 1.5 wt.%, the friction properties of the Babbitt alloy deteriorate significantly. The optimized Babbitt alloy SnSb11Cu6-1.5Co was subsequently fabricated into wires, followed by conducting cold metal transfer (CMT) surfacing experiments. The Co element can promote the growth of interfacial compounds. The microstructure at the interface of the Babbitt alloy/steel is dense, and there is element diffusion between it. The metallurgical bonding is good, and there are serrated compounds relying on the diffusion layer to extend to the direction of the additive layer with serrated compounds extending and growing from the diffusion layer to the additive layer. Overall, Babbitt alloys such as SnSb11Cu6 exhibit improved comprehensive properties when containing 1.5 wt.% Co. Full article

Heavy metals represent a significant hazard in textile wastewater, posing a considerable risk to both the ecosystem and human health. The objective of this study was to analyze the removal efficiency of specific heavy metals in a large wastewater treatment plant (WWTP) located in Prato (Tuscany, Italy), where the main Italian textile district is based. To achieve this, the mass balance calculation approach was employed. Therefore, two monitoring campaigns were conducted, collecting wastewater and sludge samples in some specific sections of the WWTP. The concentrations of Pb, Cd, Ni, As, and Sn were consistently below the detection limits. A good removal efficiency was determined for Zn, Cu, Ba, Cr^tot, and Sb, in the range of 37–79%. These metals are predominantly present in particulate form, facilitating their removal through sedimentation. Conversely, boron is largely present in the dissolved phase, resulting in its complete release through the treated effluent. Subsequently, an excellent linear correlation was identified between the input load and the contaminant load removed. This demonstrated that the plant’s efficiency remains unaffected by an increase in the input load at the observed contaminant concentrations. Finally, a probability law was identified that demonstrates an excellent degree of approximation in representing inlet metal concentrations. The findings of this study indicate that the treatment systems employed by the WWTP are capable of effectively removing heavy metals. Full article