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Bacterial exopolysaccharides (EPS) have emerged as one of the key players in the field of heavy metal-contaminated environmental bioremediation. This study aimed to characterize and evaluate the metal biosorption potential of EPS produced by a novel Psychrobacillus strain, NEAU-3TGS, isolated from an iron ore deposit at Tamra iron mine, northern Tunisia. Genomic and pan-genomic analysis of NEAU-3TGS bacterium with nine validated published Psychrobacillus species was also performed. The results showed that the NEAU-3TGS genome (4.48 Mb) had a mean GC content of 36%, 4,243 coding sequences and 14 RNA genes. Phylogenomic analysis and calculation of nucleotide identity (ANI) values (less than 95% for new species with all strains) confirmed that NEAU-3TGS represents a potential new species. Pangenomic analysis revealed that Psychrobacillus genomic diversity represents an "open" pangenome model with 33,091 homologous genes, including 65 core, 3,738 shell, and 29,288 cloud genes. Structural EPS characterization by attenuated total reflectance-Fourier transform infrared (ATRFTIR) spectroscopy showed uronic acid and α-1,4-glycosidic bonds as dominant components of the EPS. X-ray diffraction (XRD) analysis revealed the presence of chitin, chitosan, and calcite CaCO3 and confirmed the amorphous nature of the EPS. Heavy metal bioabsorption assessment showed that iron and lead were more adsorbed than copper and cadmium. Notably, the optimum activity was observed at 37°C, pH=7 and after 3 h contact of EPS with each metal. Genomic insights on iron acquisition and metabolism in Psychrobacillus sp. NEAU-3TGS suggested that no genes involved in siderophore biosynthesis were found, and only the gene cluster FeuABCD and trilactone hydrolase genes involved in the uptake of siderophores, iron transporter and exporter are present. Molecular modelling and docking of FeuA (protein peptidoglycan siderophore-binding protein) and siderophores ferrienterobactine [Fe+3 (ENT)]-3 and ferribacillibactine [Fe+3 (BB)]-3 ligand revealed that [Fe+3 (ENT)]-3 binds to Phe122, Lys127, Ile100, Gln314, Arg215, Arg217, and Gln252. Almost the same for [Fe+3 (ENT)]-3knowledge, this is the first report on the characterization of EPS and the adsorption of heavy metals by Psychrobacillus species. The heavy metal removal capabilities may be advantageous for using these organisms in metal remediation. [ABSTRACT FROM AUTHOR]

The article discusses the Gabriel Copper, a native copper specimen from the Central mine in Keweenaw County, Michigan, which is part of the collection at the A. E. Seaman Mineral Museum of Michigan Technological University. The Gabriel Copper is known for its aesthetic balance, quality of crystallization, lovely patina, interesting twinning, and perfect size. It has been extensively used to represent the museum and its heritage, appearing on book covers, magazine covers, articles, brochures, and business cards. The article also provides information about Donald C. Gabriel, the collector who purchased the specimen, and the history and collections of the A. E. Seaman Mineral Museum. [Extracted from the article]

Lake Tanganyika, the second deepest lake in Africa, has a unique ecosystem that provides rich fish proteins for populations along the lake basin. With socioeconomic development and rapid population growth, Lake Tanganyika is threatened by environmental pollution. In this study, the concentrations of heavy metals, including Cr, Ni, Cu, Zn, Cd, Pb, Fe, and Mn, in the surface sediments of the inflow rivers in northeastern quadrant of Lake Tanganyika were characterized. The geoaccumulation index (Igeo) and enrichment factor (EF) were employed for heavy metal assessment. The results showed that heavy metal concentrations in the surface sediments of the inflow rivers in northeastern quadrant of Lake Tanganyika exhibited significant spatial variations. The concentration of heavy metals was the highest near urban areas, followed by the estuarine wetland and forest grassland. This indicated that heavy metal content was closely related to human activities. The concentrations of Zn, Cd, and Pb were defined as unpolluted, and the concentrations of Pb, and Fe were only slightly enriched. Principal component analysis and cluster analysis demonstrated that the heavy metals Cr, Zn, Cd, and Pb may originate from a mixture of natural sources and anthropogenic inputs, including agricultural and industrial inputs. Ni, Fe, and Mn were principally from natural sources, and Cu primarily originated from anthropogenic inputs such as vanadium iron ore mining and iron and steel smelting. These results are important for understanding the nonpoint sources of heavy metal pollution in the Lake Tanganyika Basin. [ABSTRACT FROM AUTHOR]

This study delves into the mechanical properties of steep and rocky slopes subjected to long-term freeze-thaw actions. Considering the unique climatic conditions in cold regions, especially the significant impact of seasonal and diurnal temperature variations on slope excavation, the research focuses on a high-cold region iron ore mine. Four types of rocks commonly found in the mining area are thoroughly examined, taking into account the hydrogeological conditions of the mining area. The study systematically analyzes the mechanisms of various factors such as weathering, freeze-thaw cycles, and ice-water phase changes on the stability of cold region fractured rock masses. The research reveals that under prolonged freeze-thaw actions, crack water within the rock continuously undergoes ice-water phase changes, generating substantial freeze expansion forces that result in structural damage to the rock mass. This damage is evident not only in the development of existing microcracks but also leads to the generation of new fractures, ultimately causing deterioration in the rock mass structure. The study of the evolution patterns of freeze-thaw forces contributes to a better understanding of slope stability issues in cold region mineral resource extraction, offering crucial insights for the design, construction, and operation of related engineering projects. [ABSTRACT FROM AUTHOR]

Arbuscular mycorrhizal fungi (AMF) might amend the toxicity of trace elements and improve the nutritional status of plants, but little is known about these responses in tropical native plants in iron-ore-impacted sites with excess zinc (Zn). We evaluated how the association with AMF contributes to the resistance capacity of Stryphnodendron adstringens to high Zn concentrations in mining waste. Seeds were sown in pots containing iron-ore mining waste with different concentrations of Zn (0, 100, 200, 400 and 600 mg L−1) and two conditions (inoculated or not with AMF). The biomass accumulation and physiological processes were severely impacted in the mining waste with Zn concentration above 100 mg L−1. The relative growth rate (RGR) and the concentration of phosphorus (P) in the shoot were higher in the AMF-inoculated plants, mainly when cultivated without Zn excess. Non-inoculated plants presented the lowest net photosynthetic rate (An) mainly due to impairment in light use efficiency, especially under Zn excess. The treatments did not change stomatal conductance, transpiration, Rubisco carboxylation rate, triose-phosphate utilization and respiration rate. The AMF improved the plant resistance capacity in mining waste substrate by promoting decreased oxidative damage, ameliorated P nutrition, higher RGR, root biomass and An. [ABSTRACT FROM AUTHOR]

The mining sector plays a significant role in the economic development of countries by contributing to their gross domestic product. Once the demand for commercialized ore grows, the mining industry looks for new technologies to boost exploration and manage residue disposal. One promising technique to dispose of these residues is dry stacking. This research investigates the behavior of cemented iron ore tailings (IOTs) that use unconfined compression strength (UCS) and triaxial testing. The UCS tests investigated different dosages of cement–tailings compacted blends. In addition, nine triaxial tests were carried out, where six were cured under atmospheric pressure, and three were cured under 300 kPa. Samples were sheared under mean effective stresses of 300 and 3,000 kPa. Both curing conditions were subjected to drained axial loading, constant mean effective stress (p′), and lateral unloading stress paths. The results indicate that the porosity/cement index (η/Civ) could control the mixtures' UCS. The triaxial tests revealed the effective strength parameters stress dependence. Samples that were consolidated under high stress might experience bond breakage, which leads to a decrease in the friction angle and a tendency toward critical state conditions. No meaningful variation was observed between samples that were cured under stress and atmospheric pressure. [ABSTRACT FROM AUTHOR]

Banded iron formations (BIFs) archive the relationship between Earth's lithosphere, hydrosphere, and atmosphere through time. However, constraints on the origin of Earth's largest ore deposits, hosted by BIFs, are limited by the absence of direct geochronology. Without this temporal context, genetic models cannot be correlated with tectono-thermal and atmospheric drivers responsible for BIF upgrading through time. Utilizing in situ iron oxide U-Pb geochronology, we provide a direct timeline of events tracing development of all the giant BIF-hosted hematite deposits of the Hamersley Province (Pilbara Craton, Western Australia). Direct dating demonstrates that the major iron ore deposits in the region formed during 1.4 to 1.1 Ga. This is one billion to hundreds of millions of years later than previous age constraints based upon 1) the presence of hematite ore clasts in conglomerate beds deposited before ~1.84 Ga, and 2) phosphate mineral dating, which placed the onset of iron mineralization in the Province at ~2.2 to 2.0 Ga during the great oxidation event. Dating of the hematite clasts verified the occurrence of a ~2.2 to 2.0 Ga event, reflecting widespread, but now largely eroded iron mineralization occurring when the Pilbara and Kaapvaal cratons were proximal. No existing phosphate mineral dates overlap with obtained hematite dates and therefore cannot be related to hematite crystallization and ore formation. New geochronology conclusively links all major preserved hematite deposits to a far younger (1.4 to 1.1 Ga) formation period, correlated with the amalgamation of Australia following breakup of the Columbia supercontinent. [ABSTRACT FROM AUTHOR]

The effect of inter-ring delay time (IRDT) on rock fragmentation in the tunnel excavation blasting was studied at the Xinjiang Beizhan Iron Mine, China, to improve the rock fragmentation and optimize the blast design. Blasting tests were conducted with an IRDT of 50, 100, 150, 200, and 500 ms; each adjacent ring had an equal IRDT, and two replicate tests were conducted. The blasting plan with IRDT of 100 ms was the original blasting plan used in the mine. Two optimized blasting plans were proposed and implemented based on the experimental results, along with a control experiment using the original blasting plan. The fragment size of each blast test was measured and analyzed by the block-analyzed software. Both collision theoretical and field tests indicated that the IRDT plays an important role in rock fragmentation and that as the IRDT increases, the degree of rock fragmentation increases first and then decreases. For example, the fragment sizes X20, X50, and X80 showed an increase followed by a decrease; the percentage of large fragments (1-P750) showed a decline followed by a rise; the percentage of small fragments P25 showed an increase followed by a decline. The blasting plan with an IRDT of 150 ms had the most optimal rock fragmentation effect, with the lowest percentage of large fragments, the highest percentage of small fragments, and the smallest average fragment size of X50. Furthermore, the two optimized blasting plans demonstrated better control over blasting costs and rock fragmentation compared to the original blasting plan. [ABSTRACT FROM AUTHOR]

In general, the design of a safe and rational laneway support scheme signifies a crucial prerequisite for ensuring the security and efficiency of mining exploitation in mines. Nevertheless, the conventional empirical support system for mining laneways faces challenges in assessing the rationality of support methods, which can compromise the safety and reliability of the laneways. To address this issue, the safety factor was incorporated into research on laneway support, and a safety evaluation method for laneway support in line with the safety factor was established. In light of the data from a specific iron mine laneway in central China, the CRITIC method was employed to preprocess the sample data. Going one step further, a Bayesian algorithm was utilized to optimize the hyperparameters of the CatBoost model, followed by proposing a prediction model based on the BO-CatBoost model for evaluating laneway safety factors of plain shotcrete support. Furthermore, the performance indexes, such as the root mean square error (RMSE), the mean absolute error (MAE), the correlation coefficient (R2), the variance accounts for (VAF), and the a-20 index, were determined to examine the predictive performance of each proposed model. In contrast to the other models, the BO-CatBoost model demonstrated the optimal predictive output item for safety factors with the lowest RMSE and MAE, the largest R2 and VAF, and an appropriate a-20 index value of 0.5688, 0.4074, 0.9553, 95.25%, and 0.9167 in the test set, respectively. Therefore, the BO-CatBoost model was proven to be the most appropriate machine learning method that can more accurately predict the safety factor, which will provide a novel approach for optimizing laneway support design and laneway safety evaluation. [ABSTRACT FROM AUTHOR]

The reverse circulation down-the-hole air hammer drilling (RC-DTH) method is renowned for its efficiency in hard rock formations and exceptional dust control performance. It presents opportunities for cost-saving, efficiency improvement, energy conservation, and environmental protection. Reverse circulation drill bits are critical components of this method. This study focused on the air reverse circulation regime, investigating various geometric parameters of the RC drill bits through computational and experimental methods to enhance its dust control performance. Results indicate that increasing the layers of suction nozzles, enlarging the diameters of the suction and mixing nozzles, and optimizing the input airflow rate can effectively channel airflow toward the central passage of the drill tool. Consequently, this optimization significantly improves the dust control performance of the RC drill bits. Conversely, increases in the flushing nozzle diameter and alterations in the suction nozzle location have detrimental effects on the dust control capability of the RC drill bits. Field tests were conducted at the Yuan Jiacun iron mine, affiliated with Taiyuan Iron and Steel (Group) CO., LTD. The field tests demonstrate that the optimized RC drill bit exhibits excellent dust performance. [ABSTRACT FROM AUTHOR]

High iron ore production generates substantial solid waste. Storing this waste in dams poses environmental issues and safety risks for the population. The aim of this study was to valorize sterile waste (IOT) from an inactive iron mine in the Nador region of northeastern Morocco, as an additive in the manufacture of fired bricks made from a red clay (AJH) extracted from the Oujda region. For this purpose, brick specimens were obtained using a mix of a 40% of AJH and 60% of IOT. Physico-chemical, geotechnical and mineralogical characterization techniques were applied to qualify raw material. IOT consisted of hematite, magnetite, pyrite, jarosite and quartz and AJH of kaolinite, chlorite, calcite, hematite, dolomite, quartz and vermiculite. After firing the specimens at 500 °C, 850 °C and 1100 °C, mineralogical composition, bulk density, compressive strength and microstructure behavior of the specimens was assessed. The compressive strength of the bricks containing IOT is 1.25 MPa at T = 500 °C and it varies little at 1100 °C. The compressive strength of the reference sample is 2.94 MPa at 1100 °C. The material has low vitrification and greater porosity compared to the reference bricks. Adding IOT brings significant changes to the color of fired bricks. [ABSTRACT FROM AUTHOR]

This study investigated the migration, transformation, and clustering characteristics of trace elements in the abandoned mining areas before and after the rain, using rainfall as a basis. The precipitation-driven factors and the potential migration direction of metals in a highly complex soil-surface water-groundwater system were studied. The local spatial auto-correlation analysis used the Moran index to implement LISA clustering, and to clarify the effect of rainfall on the accumulation and dispersion of metals in different environmental mediums of mining areas. The results show that the spatial clustering of Cd, Pb, Cr, Hg, and As is observed in the topsoil, with mean concentrations of 0.23, 30.07, 236.38, 1.32 and 5.60 mg·kg−1, respectively. Rainfall significantly increased the concentrations of trace elements in the shallow groundwater, and therefore drove water circulation in the watershed. Moreover, trace element ions are migrated with the watershed water. The rainfall led to the migration of at least 13.37% Pb, 10.44% Cr, 29.55% Hg, and 15.71% As from the topsoil, with some exhibiting spatial clustering or appearing as outliers in surface water and groundwater. Pb tends to migrate laterally into the soil in the study area, whereas Cr and As exhibit the characteristics of vertical migration. Hg shows a propensity for both lateral and vertical migration simultaneously. Consequently, trace elements in the soil and water exhibit strong spatial influences in mining areas, resulting in high spatial heterogeneity. Furthermore, trace elements showed greater susceptibility to vertical migration in gold mining areas, and lateral migration with water recharge in iron mining areas. [ABSTRACT FROM AUTHOR]

One of the challenges facing our current and future generations is the effective management of energy and its acquisition through more sustainable means. One solution is using materials capable of generating energy from temperature differences. Construction materials could be the answer, as they are already integrated into structures and have good thermoelectric properties. Geopolymers, emerge as a promising candidate due to their enhanced sustainability compared to alternative materials. Our research explored the use of geopolymers for electricity generation from heat. To minimize the usage of kaolin, we incorporated 50 % of two mining residues obtained from old mines located in Portugal. This approach optimizes the utilization of mineral resources and mitigates the environmental impact. Various methods were used to characterize this material, such as X-ray diffraction, simple compressive strength tests and evaluation of thermoelectric properties, such as the Seebeck coefficient and figure of merit. The geopolymers tested exhibit semiconductor characteristics, demonstrating poor heat conduction due to their low thermal conductivity. Regarding thermoelectric properties, these materials display N-type behavior, with a Seebeck Coefficient between −643 μV/°C and −2760 μV/°C. These findings underscore the advantages of utilizing this sustainable material for the widespread implementation of energy management in buildings on a large scale. [ABSTRACT FROM AUTHOR]

Iron ore has had a highly global market since setting a new pricing mechanism in 2008. With current dollar values, iron ore concentrate for sale price, which was $39 per tonne (62% Fe) in December 2015, reached $218 per tonne (62% Fe) in mid-2021. It is hovering around $120 in October 2023 (cf. https://tradingeconomics.com/commodity/iron-ore). The uncertainty associated with these fluctuations creates hardship for iron ore mine operators and steelmakers in planning mine development and making future sale agreements. Therefore, iron ore price forecasting is of special importance. This paper proposes a cutting-edge multi-echelon tandem learning (METL) model to forecast iron ore prices. This model comprises variational mode decomposition (VMD), multi-head convolutional neural network (MCNN), stacked long short-term-memory (SLSTM) network, and attention mechanism (AT). In the proposed METL (i.e., the combination of VMD, MCNN, SLSTM, AT) model, the VMD decomposes the time series data into sub-sequential modes for better measuring volatility. Then, the MCNN is applied as an encoder to extract spatial features from the decomposed sub-sequential modes. The SLSTM network is adopted as a decoder to extract temporal features. Finally, the AT is employed to capture spatial–temporal features to obtain the complete forecasting process. Extensive computational experiments are conducted based on daily-based and weekly-based iron ore price datasets with different time scales. It was validated that the proposed METL model outperformed its single-echelon and other categorized models by 10–65% in range. The proposed METL model can improve the prediction accuracy of iron ore prices and thus help mining and steelmaking enterprises to determine their sale or purchase strategies. [ABSTRACT FROM AUTHOR]

A minequake of magnitude ML 4.1 occurred on 18 May 2020 early in the morning at the LKAB underground iron ore mine in Kiruna, Sweden. This is the largest mining‐induced earthquake in Scandinavia. It generated acoustic signals observed at three infrasound arrays at 9.3 (KRIS, Sweden), 155 (IS37, Norway), and 286 km (ARCI, Norway) distance. We perform full‐waveform focal mechanism inversion based on regional seismic data and local infrasound data. These independently highlight that this event was dominated by a shallow‐depth collapse in agreement with in‐mine seismic station data. However, regional infrasound data cannot inform the inversion process without an accurate model of atmospheric winds and temperatures. Yet, our numerical simulations demonstrate a potential of using local and regional infrasound data to constrain an event's focal mechanism and depth. Plain Language Summary: The largest mining‐induced earthquake in Scandinavia (ML 4.1) occurred on 18 May 2020 early in the morning at the LKAB underground iron ore mine in Kiruna, Sweden. The seismic waves coupled to the atmosphere and propagated large distances as sound waves which were observed at three infrasound arrays at 9.3 (KRIS, Sweden), 155 (IS37, Norway), and 286 km (ARCI, Norway) distance. Our seismic and acoustic modeling results highlight a strong collapse event within the northern section of the mine. The modeling of acoustic and seismic waves across the Earth‐atmosphere suggests that sound wave data can help when determining the location and properties of a seismic source. Key Points: Seismic and acoustic records indicate a strong collapse at shallow depth of 1 ± 0.5 km for the 2020 Kiruna minequakeFocal mechanisms and depths of shallow seismic sources can be retrieved from local infrasound recordsInversions using regional infrasound data is possible when accurate weather models are available [ABSTRACT FROM AUTHOR]

In the long-hole stage open stoping with subsequent backfill mining of underground metal mines, the selection or optimization of stope dimension parameters is significant for safe and economic mining operations. To analyze the optimal stope sizes, the Mathews empirical graph method and FLAC3D numerical method can be used, but the analyzed safety results of the two methods are generally independent from each other. More importantly, economic indicators including production capacity and mining costs should be considered simultaneously to optimize the stope dimension which was mostly ignored in previous reports. In this paper, a new CRITIC-GRA model was proposed for the first time to build up a multi-factor quantitative optimization for stope dimension, which allows for a comprehensive analysis with preset influential safety and economic indicators. The indicators considered include the safety indicators such as stability probability for the side walls and roof of the open stope via the updated Mathews graph method, maximum displacement, plastic zones volume and maximum principal stress via FLAC3D simulations, as well as economic indicators such as mining costs and stope production capacity in mine operations. The model was then illustrated in an underground iron mine. With the given rockmass quality in the mine, the overall stability of the open stope can be improved instead of reduced to enlarge the single stage stope height (60 m) to a double stage height (120 m) by reducing the stope width from 20 m to 15 m, thereby significantly increasing the mineable ore amount and improving the stope safety. An integrated evaluation of open stope stability, mining capacity and costs objectively determined that scheme No. 10, with a slope length of 50 m, a width of 15 m and a height of 120 m, was the optimum out of the 20 preset schemes. The new CRITIC-GRA model offers a dependable reference tool for determining the optimal stope dimensions in similar underground mines. [ABSTRACT FROM AUTHOR]

A three-dimensoonal numerical simulation model was established usnng FLAC3D software'combined with finite eeement theory'to study the surface subsidence sssue during the transition from openpt to underground mnnnng in a certain iron mine in Liaonnng province. The research results indccate that with an nncrease nn backiiliing rate'the maximum principal stress and vertical displacement of the roof exhibit a decreasnng trend. In the case of timely backiling after the first minnng stage at a depth of --40 meters'the maximum vertical displacement decreased by 45% for a 100% backfiling rate compared to a 90% backfiling rate. When mining reached the middle section at a depth of 305 meters'the verical displacement decreased by 22% for a 100% backiiliing rate compared to a 90% backiiliing rate. Both the verical and horizontal displacements at the surface monitoring points decrease with an nncrease in the backiiliing rate. With a backfiling rate of 95% guaranteed' the impact of underground mining on surface structures ss re!aively small' meeing the permissible surface deformation values specified by regu!ations. These research iindings provdde valuaWe references for understanding the surface subsidence patterns during the transiion from open-pit to underground mining nn this mine. [ABSTRACT FROM AUTHOR]

Wet beneficiation is a primary process employed by mining companies for iron ore concentration. The moisture content in the ore is a result of this beneficiation process, in addition to inherent moisture within the mineral composition. The moisture content of iron ore is a crucial parameter that requires effective control to ensure safe handling and transportation operations. Surface plasma treatment of iron ore has been investigated as a method to enhance the hydrophobicity of ore particles, thereby reducing residual moisture and water reabsorption by the particles. The samples underwent treatment using argon plasma and cold hexamethyldisiloxane (HMDSO) plasma, leading to the formation of a thin, silicon-rich surface layer. The treatments were applied to both polished ore samples and fine powder samples. The plasma treatment resulted in a reduction in moisture content and water absorption. The reabsorption of water decreased to approximately 35% of the pretreatment values. Contact angle measurements demonstrated that all HMDSO-treated samples exhibited hydrophobic behavior, with contact angles ranging from 110° to 120°, while the untreated samples exhibited angles close to 0°. Furthermore, atomic force microscopy (AFM) topographic imaging revealed a granular structure in the thin films. [ABSTRACT FROM AUTHOR]

The rupture of an iron mining tailing dam in Brumadinho, Brazil, released around 10 million cubic meters of tailings, of which 1.6 Mm3 reached the Paraopeba River. In this work, a total of 30 samples from three bottom sediment cores were collected in the lower course of the Paraopeba River basin and analyzed for major, trace and rare earth elements by ICP-OES and ICP-MS. The sediments presented a range of compositions with different weathering histories, overall marked by depleted Ca2+, Na+ and K+ compared with the average UCC, PAAS and NASC and some advanced weathering trends. The samples presented a fractionation pattern characterized by a continuous depletion of light REEs from La to Sm and a regular decreased distribution of heavy REEs from Gd to Yb, and the Co/Th vs. La/Sc diagram indicates a predominant intermediate source. The upper samples presented the highest contents of REEs, probably due to the higher presence of iron and aluminum oxides and hydroxides, which can be related to more advanced weathering. The Al, Cu, Ni, V, Zn, Co, Mn, Ti, Fe and Si concentrations and the CF, EF and Igeo index values varied across the sediment core samples, demonstrating that there were long periods of geogenic or anthropogenic contributions. [ABSTRACT FROM AUTHOR]

The Southeastern Hubei Ore Concentration Area (SHOCA) is located in the west section of the Middle and Lower Yangtze River Metallogenic Belt in China, and it is a significant copper and iron mining region in China. Here, 117 pieces of magnetotelluric array data were used to obtain a three-dimensional resistivity model of the SHOCA and to investigate the relationship between the deep electrical features and the genesis of mineral deposits. The model shows that the Qinling-Dabie Orogenic Belt exhibits high-resistivity characteristics, representing Mesozoic granites and high-pressure to ultra-high-pressure metamorphic rocks. There are several low-resistivity anomalies in the upper crust of the SHOCA, which are connected to the widespread low-resistivity anomaly in the middle-lower crust. Near the Yangxin-Changzhou Fault, there is evidence of an electrical gradient zone. The Xiangfan-Guangji Fault, located at the south margin of the Qinling-Dabie Orogenic Belt, also exhibits distinct high- and low-resistivity boundaries at the upper crust. However, the Yangtze Fault and the Tancheng-Lujiang Fault manifest as resistivity gradient zones at the lithospheric scale. These faults are connected the low-resistivity anomaly in the middle to lower crust, possibly serving as upwelling channels of deep thermal fluids, exerting control over shallow diagenesis and mineralization processes. The low-resistivity anomaly in the middle to lower crust of the SHOCA is explained as partial melting resulting from the mixing of crustal and mantle materials. These low-resistivity anomalies play a role as source components in the mineralization system, where mineral-rich hydrothermal fluids migrate upward along intra-basin faults, exerting control over the distribution of shallow mineral deposits. [ABSTRACT FROM AUTHOR]

The anaerobic digestion process (AD) occurs via series of biochemical reactions, producing biogas as a renewable fuel and digestate, a rich by-product in trace elements (TEs), which has been directly disposed on soils as organic fertilizer. The application of mineral additives can result higher biogas production and CH4 yields in AD process; however, the chronical effects of these additives in digestates have not been reported in the literature. In this way, this research aims to analyze the chronic effects of digestates from swine manure (SD) and swine manure with iron ore tailings as additive (SDIOT) on survival and reproduction of Enchytraeus crypticus. The fresh samples were collected from sequential batch processes conducted at mesophilic conditions. The TEs and pH ranges in feedstock and digestates were determined in fresh matter (mg L−1), including analyses of heavy metals and nutrients, in which ranges concentrations were discussed according to biogas and CH4 productions, and compared with previous data of literature. These analyses were followed by chronic tests of digestates on reproduction of E. crypticus in Oxisols, in which tests performance met the validity criteria stablished according to ISO 16387 standard. The means of treatments were compared using the Holm–Sidak method, and the means of control groups were compared using t test (α = 0.05). The chronic effect on survival and reproduction of organisms might have occurred through synergistic effect of metals in digestates; however, more analyses must be needed to understand the toxicity effect of these products, specially under different climate conditions. Article Highlights: The application of swine manure resulted in a chronic effect to Enchytraeus crypticus. The synergistic effect of metals might have effects on organisms survival. Available fractions of metals and chemical properties of soils must also be evaluated. Climate change might influence on the speciation of metals within the soils. [ABSTRACT FROM AUTHOR]

The frequency of skeletal deformations in fish is a common biomarker when investigating the environmental response to effluents of various origins. This study discovered a new biomarker: elevated mineralization levels of the vertebrae in the caudal region of perch Perca fluviatilis. The study was conducted in northern Sweden in lakes receiving discharges from an iron ore mine and adjacent reference lakes. The field observation was followed up with an egg‐hatching experiment showing a similar lake‐specific pattern in hatching and deformation frequencies in larvae. [ABSTRACT FROM AUTHOR]

Introduction: The microbial-induced restoration of ferruginous crusts (canga), which partially cover iron deposits and host unique ecosystems, is a promising alternative for reducing the environmental impacts of the iron mining industry. Methods: To investigate the potential of microbial action to accelerate the reduction and oxidation of iron in substrates rich in hematite and goethite, four different microbial treatments (water only as a control - W; culture medium only - MO; medium + microbial consortium - MI; medium + microbial consortium + soluble iron - MIC) were periodically applied to induce iron dissolution and subsequent precipitation. Except for W, all the treatments resulted in the formation of biocemented blocks. Results: MO and MI treatments resulted in significant goethite dissolution, followed by precipitation of iron oxyhydroxides and an iron sulfate phase, due to iron oxidation, in addition to the preservation of microfossils. In the MIC treatment, biofilms were identified, but with few mineralogical changes in the iron-rich particles, indicating less iron cycling compared to the MO or MI treatment. Regarding microbial diversity, iron-reducing families, such as Enterobacteriaceae, were found in all microbially treated substrates. Discussion: However, the presence of Bacillaceae indicates the importance of fermentative bacteria in accelerating the dissolution of iron minerals. The acceleration of iron cycling was also promoted by microorganisms that couple nitrate reduction with Fe(II) oxidation. These findings demonstrate a sustainable and streamlined opportunity for restoration in mining areas. [ABSTRACT FROM AUTHOR]

Recycling solid waste into electrocatalysts for renewable energy systems is crucial for sustainable development, achieving a win-win strategy for environmental remediation and waste utilization. The global use of iron-based disposable chemical warmers results in the generation of a significant amount of solid waste. This study demonstrates the upcycling of disposed iron-based chemical warmers into bifunctional Fe/Fe3O4/NC electrocatalysts. The synthesized catalysts exhibited excellent electrocatalytic activity for the hydrogen evolution reaction (HER) and the oxygen evolution reaction (OER). Fe/Fe3O4/NC for HER and OER performance requires overpotentials of only 160 and 230 mV, respectively, to achieve 10 mA cm−2. This catalyst exhibited excellent bifunctional performance, achieving a low cell voltage of 1.53 V to reach a current density of 10 mA cm−2 for overall water splitting. The synergistic interaction of the metal–metal oxide (Fe–Fe3O4) interface and N-doped carbon significantly enhances the catalytic activity. This work synergistically addresses the sustainable utilization of waste materials, contributes to resource conservation, reduces energy consumption in iron ore mining processes, and mitigates environmental pollution. [ABSTRACT FROM AUTHOR]

In order to comprehensively utilize iron ore tailings (IOTs), the possibility of using IOTs as raw materials for the preparation of cementitious composites (IOTCCs) was investigated, and IOTCC was further applied to mine interface pollution control. The mechanical properties, hydration products, wind erosion resistance, and freeze–thaw (F–T) cycle resistance of IOTCCs were evaluated rigorously. The activity index of iron tailings increased from 42% to 78% after grinding for 20 s. The IOTCC was prepared by blending 86% IOT, 10% ground granulated blast-furnace slag (GGBS), and 4% cement clinker. Meanwhile, the hydration products mainly comprised ettringite, calcium hydroxide, and C-S-H gel, and they were characterized via XRD, IR, and SEM. It was observed that ettringite and C-S-H gel were principally responsible for the strength development of IOTCC mortars with an increase in curing time. The results show that the kaolinite of the tailings was decomposed largely after mechanical activation, which promoted the cementitious property of IOT. [ABSTRACT FROM AUTHOR]

The exploitation of iron ore could cause heavy metals pollution in the soils, which threatens the ecosystem and human health. In this study, soil, stream sediment, tailings, rock, and atmospheric deposition samples were collected from an iron mine in Baotou City. The concentrations of As, Cd, Cr, Cu, Hg, Ni, Pb, Zn, Al2O3, CaO, K2O, MgO, Na2O, SiO2, and Fe2O3, as well as the mineral composition and heavy metal speciation of the samples, were analyzed for pollution assessment and source identification of heavy metals. The results reveal that the concentration of Cu in the soils was significantly higher than the background value, and an unpolluted to moderately polluted state was the main pollution level. By analyzing the relationship between Cu/Al2O3 and CaO in different samples, as well as the characteristics of the chemical index of alteration (CIA), mineral composition, and the chemical speciation of Cu in soils and profiles, the results suggest that tailings were the source of Cu pollution in soils. The distribution characteristics of Cu and CaO in stream sediments indicated that hydraulic transport may be one of the main migration pathways. In addition, wind transport may also be a pathway of migration. [ABSTRACT FROM AUTHOR]

The target reliability of mine rock slopes must be scientifically determined, which can fully reflect the safety level of slope stability and plays an essential role in establishing slope reliability design guidelines. Since the design guidelines based on reliability methods have not been established for mine rock slopes, the suggested target reliability values are proposed based on the grey fixed weight clustering and analogy method. Firstly, a new evaluation method of slope safety grade is proposed by considering more influencing factors of slopes. Secondly, the grey fixed weight clustering is used to quantitatively processes the slope reliability data, and the slope safety grade is judged. Then, the target reliability of each grade is obtained by the analogy method. Finally, the equal difference method is applied to set the threshold of allowable failure probability for the minimum service life of slopes, and the reliability of other service life is processed by linear interpolation. The results show that, the target reliability of the maximum service life for grade I, II, III ductile failure is 3.25, 2.75, 2.25, and brittle failure is 3.75, 3.25, 2.75, respectively. the allowable failure probability of the minimum service life for each grade shows that the ductile failure is 1%, 3%, 5% and brittle failure is 0.5%, 1%, 3%, respectively. In addition, the suggested values of Inter-ramp and Bench slopes are also improved, and a case study is conducted in the Jinbao iron mine to illustrate the feasibility of the method and results in this paper. [ABSTRACT FROM AUTHOR]

The evaluation and classification of goaf stability are fuzzy and random. To address this problem, a new classification method is proposed. A cavity monitoring system is used to detect the goaf, 3DMine and FLAC3D software are used to conduct the 3D visual modeling of the scanning results, and numerical simulation analysis is performed on the goaf. According to the analysis results, the stability classification standard of the goaf is constructed, and the characteristics of each classification are described. The evaluation indicator system of goaf stability is constructed in accordance with similar engineering experience, and the evaluation indicator is weighted by using the analytic hierarchy process. The cloud–element coupling evaluation model is built, the field measured values of indicators are collected, the cloud correlation degree of goafs belonging to each stability level is calculated, the stability level is evaluated according to the principle of maximum membership degree, and the results are compared with the numerical simulation to analyze the reasons for the differences in the stability evaluation results obtained by the two methods and to improve the accuracy of the evaluation of goaf stability. The pillar stress and surrounding rock deformation are monitored in Room 1# of the inclined mining area of Shirengou Iron Mine. The monitoring results are consistent with the evaluation results, which proves the accuracy of the proposed goaf stability classification method. [ABSTRACT FROM AUTHOR]

Copyright of Revista Foco (Interdisciplinary Studies Journal) is the property of Revista Foco and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The main sources of redox gradients supporting high-productivity life in the Europan and other icy ocean world oceans were proposed to be photolytically derived oxidants, such as reactive oxygen species (ROS) from the icy shell, and reductants (Fe(II), S(-II), CH4, H2) from bottom waters reacting with a (ultra)mafic seafloor. Important roadblocks to maintaining life, however, are that the degree of ocean mixing to combine redox species is unknown, and ROS damage biomolecules. Here, we envisage a unique solution using an acid mine drainage (AMD)-filled pit lakes analog system for the Europan ocean, which previous models predicted to be acidic. We hypothesize that surface-generated ROS oxidize dissolved Fe(II) resulting in Fe(III) (hydr)oxide precipitates, that settle to the seafloor as "iron snow." The iron snow provides a respiratory substrate for anaerobic microorganisms ("breathing iron"), and limits harmful ROS exposure since they are now neutralized at the ice-water interface. Based on this scenario, we calculated Gibbs energies and maximal biomass productivities of various anaerobic metabolisms for a range of pH, temperatures, and H2 fluxes. Productivity by iron reducers was greater for most environmental conditions considered, whereas sulfate reducers and methanogens were more favored at high pH. Participation of Fe in the metabolic redox processes is largely neglected in most models of Europan biogeochemistry. Our model overcomes important conceptual roadblocks to life in icy ocean worlds and broadens the potential metabolic diversity, thus increasing total primary productivity, the diversity and volume of habitable environmental niches and, ultimately, the probability of biosignature detection. [ABSTRACT FROM AUTHOR]

The use of geophysical techniques can contribute considerably to the advancement and optimization of subsurface surveys, due to the low costs and time effectiveness. Ground penetrating radar (GPR) has great potential to rapidly and non-invasively evaluate soil in sites affected by the Fundão dam collapse, Southeastern Brazil. The objective of this work was to investigate the thickness of the iron ore tailing layer deposited in a stretch of the Gualaxo do Norte River, besides identifying the most efficient electromagnetic frequency for analysis of this type of material. Three antennas (200, 400 and 900 MHz) were used for GPR surveys in three transects. The radargrams were processed with filtering and gain techniques, aiming to improve the signal quality. We could detect three ground reflection zones with different electromagnetic properties, representing, sequentially, the topsoil, the tailing layer, and the C horizon of the original soil, separated by two reflectors representing the boundaries layers. The tailing layer presented an average thickness of approximately 1 m. 200 MHz presented the best results, whose signal reached the greatest penetration depth and detected the entire tailing layer thickness, besides the others layers present. Using field control points, we could observe that the depths obtained with radargrams had 93% of concordance with the actual depths, which is very satisfactory. The results indicate that the 200 MHz antenna is a better option in surveys involving stratification on Technosols constituted by tailings and GPR should be more explored in the evaluation of soil and sediments. [ABSTRACT FROM AUTHOR]

Using a combination of experimental and numerical methods, this study examines the stability of the slope of Waste Dump#1 in Ziluoyi Iron Mine. We conducted direct shear tests on soil samples taken from the waste dump, which provided important insights into slope stability. The tests identified key mechanical parameters, including an average cohesion of 4.80 kPa and an internal friction angle of 25.63°. By implementing GEO-SLOPE software, we could determine that the slope stability factor is 1.047, which is far from the required safety standards. To address this issue, we proposed an appropriate rectification strategy including the construction of safety platforms and reconfiguration of the slope structure. This approach effectively improved the slope stability factor to 1.219 and met the safety criteria. In addition, particle flow code (PFC) simulations were methodically performed to model the slope morphology and particle displacement before and after rectification. The obtained results revealed a remarkable reduction in sliding areas and particle displacement post-rectification, enhancing mine safety and efficiency. Our findings provide valuable insights into the application of combined experimental and numerical methods to assess and improve slope stability in open-pit mines, which will substantially contribute to the field of geotechnical engineering and mining safety. [ABSTRACT FROM AUTHOR]

Direct hydrogen reduction (H-DR) is a promising technology for green ironmaking. Given the absence of commercial H-DR data, computational simulation is a powerful tool for engineering and overcoming the complexity of the system. This study develops a multiscale moving-bed reactor model to simulate non-catalytic gas-solid reactions and evaluate parameters at the pellet scale that hierarchically impact the performance at reactor scale. The reactor and solid particles are treated as coupled physical domains, enabling the computation of the solid transformations along both scales. Predictions for H-DR process highlight the substantial supply of H 2 molar flow in enhancing reactor performance. A sensitivity multivariate analysis revealed the significant effect of pellet structural characteristics and gas inlet conditions on the process. Increased pellet porosity offers flexibility for process optimization, enabling the use of lower H 2 percentages and temperatures. These findings provide valuable insights into optimizing H-DR process, improving energy efficiency, and better H 2 utilization. [Display omitted] • Finite element method to discretize both pellet and reactor. • Multiphysics-multiscale simulation for non-catalytic gas-solid reactions. • Multivariate sensitivity analysis of the Hydrogen Direct Reduction process. • Impact of pellet structure on the reactor performance. • Identification of optimal conditions for green iron production. [ABSTRACT FROM AUTHOR]

This study examines the widespread practice of upstream tailings dam construction in metallurgical mines in China, conducting comprehensive testing and research on tailings from various depositional zones of the Caijiagou tailings pond. Analysis of the test results from three types of tailings reveals a systematic relationship between the mechanical characteristics of tailings and their depositional zones: the farther from the dam, the finer the tailings particles, categorized as silty clay tailing, silt tailing, and sandy silt tailing. Consistent patterns were observed in the consolidated-drained shear strength and consolidated-undrained effective shear strength of these tailings. Among these, sandy silt tailing exhibited the highest strength, whereas silty clay tailing displayed the lowest. The dynamic stress–strain relationships of all three tailings types are described using the Hardin equivalent viscous-elastic model, where the initial dynamic shear modulus and the maximum dynamic shear stress in the model increased with effective confining pressure. The damping ratios exhibited a three-stage trend with increasing dynamic strain: gradual increase, rapid growth, and then gradual stabilization. Under various consolidated stress conditions, the ratio of the damping ratio to the maximum damping ratio versus the reduction in dynamic shear modulus showed a favorable linear relationship. Under vibration conditions, the dynamic shear stress corresponding to tailings failure increased with higher effective confining pressure and consolidated stress ratio. Finally, this study summarizes the parameters and indicators related to the saturated tailings of iron mines used in the research. Our work provides a foundation and reference for the design of tailings dams and the development and utilization of abandoned tailings ponds. [ABSTRACT FROM AUTHOR]

Copyright of Rudarsko-Geolosko-Naftni Zbornik is the property of Faculty of Mining, Geology & Petroleum Engineering and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Arsenic contamination poses significant challenges to environmental and public health, with mining activities contributing to its wider distribution. This study investigates the fate of arsenic and iron in mine waters at a decommissioned tin mine, now a visitor mine, located in Ehrenfriedersdorf, Germany, situated in the Free State of Saxony. Despite the general shortage of data, which is common for old mining sites, we explored the complex interplay of climatic conditions, hydrological processes, and arsenic and iron behavior in the mine waters through a comprehensive approach encompassing general site characterization, mine water monitoring, and analysis of local weather data. Over a period of three years, we conducted 14 sampling campaigns, collecting a total of 95 water samples, each consisting of three filtration subsamples, resulting in the analysis of 285 water samples. These samples were collected both aboveground and underground. Aboveground samples included mine outflows, a tailing outflow, and an adjacent creek, while underground sampling points were scattered throughout the mine initially and later focused on the identified "main" mine water system. The chemical data from the analyses were correlated with local climatic water balances to reveal distinctive patterns in arsenic and iron concentrations at various locations within the mine system. Our findings shed light on the hydrological behavior of the mine, helping to elucidate the impact of precipitation and potential evapotranspiration on arsenic and iron concentrations in a tailing outflow, in the flooded mine body, and at the portal of the main dewatering gallery. Our findings emphasize the importance of sustained monitoring and the utilization of local weather data to comprehend metalloid and metal contamination risks in similar mining environments. [ABSTRACT FROM AUTHOR]

Autotrophic theories for the origin of metabolism posit that the first cells satisfied their carbon needs from CO2 and were chemolithoautotrophs that obtained their energy and electrons from H2. The acetyl-CoA pathway of CO2 fixation is central to that view because of its antiquity: Among known CO2 fixing pathways it is the only one that is i) exergonic, ii) occurs in both bacteria and archaea, and iii) can be functionally replaced in full by single transition metal catalysts in vitro. In order to operate in cells at a pH close to 7, however, the acetyl-CoA pathway requires complex multi-enzyme systems capable of flavin-based electron bifurcation that reduce low potential ferredoxin--the physiological donor of electrons in the acetyl-CoA pathway--with electrons from H2. How can the acetyl-CoA pathway be primordial if it requires flavin-based electron bifurcation? Here, we show that native iron (Fe0), but not ni0, Co0, Mo0, NiFe, Ni2Fe, Ni3Fe, or Fe3O4, promotes the H2-dependent reduction of aqueous Clostridium pasteurianum ferredoxin at pH 8.5 or higher within a few hours at 40 °C, providing the physiological function of flavin-based electron bifurcation, but without the help of enzymes or organic redox cofactors. H2-dependent ferredoxin reduction by iron ties primordial ferredoxin reduction and early metabolic evolution to a chemical process in the Earth's crust promoted by solid-state iron, a metal that is still deposited in serpentinizing hydrothermal vents today. [ABSTRACT FROM AUTHOR]

The instability of geological slopes in mining environments poses a significant challenge to the safety and efficiency of operations. Waste Dump#2 at the Ziluoyi Iron Mine in China is a notable case study that highlights the challenges associated with sizable base slopes and large step heights. To address hidden hazards in the mine and the above issues, an inclusive investigation is carried out to examine the physical and mechanical properties of the soil–rock slope through indoor testing and analyze the deformation mechanisms of the slope using numerical simulations, taking various factors into account. The study reveals that the stability of Waste Dump#2 is deeply affected by weight, groundwater conditions, earthquake loading, and rainfall. To this end, the cohesion and internal friction parameters of the soil–rock slope are first determined through direct shear tests, which show a cohesion of 6.215 kPa at the top of the slope and an internal friction angle of 34.12°. By adopting GEO-SLOPE, 3D Mine, and AutoCAD software, stability calculations of the slope are performed, which give stability coefficients of 1.547 under normal conditions, 1.276 in rainfall, and 1.352 in seismic conditions. These results meet safety standards and ensure the safe and efficient operation of the mine. [ABSTRACT FROM AUTHOR]

In-pit crushing and conveying (IPCC) is considered a suitable alternative to truck haulage in open pit mines because it offers a lower operating cost than a truck-shovel system. It also reduces truck haulage distance and truck requirements. One of the IPCC variations is the semi-mobile system, which is relocated every two to five years. The short-term plan needs to be updated accordingly, based on the crusher's optimal location and relocation time. To the best of our knowledge, short-term planning with IPCC is an area of research that has not been explored extensively yet and hardly any model can generate short-term schedules considering an IPCC in place. This research work proposes a mixed integer programming model to generate short-term production plans and near-optimal shovel allocation to mining faces, within a time horizon of 12 months. The objective of the model is to minimise the cost of material handling and maximise revenue, with respect to plant requirement, maximum allowable tonnage variation and IPCC location constraints, and the production and NPV targets set by the strategic plan. An iron ore mine case including a semi-mobile IPCC (SMIPCC) system with one relocation is used as the case study to verify the proposed model. The comparison of results between scenarios with and without IPCC justifies the use of IPCC in the iron ore mine from a short to medium-term perspective. The project can be considered a pioneering work in the arena of short-term mine planning with the IPCC. [ABSTRACT FROM AUTHOR]

Taking the Xinshan iron ore mine as an example, this paper, based on collecting and analyzing the actual production data and similar simulation test data of this iron ore mine, analyses various factors affecting ore depletion by bottomless column segmental chipping method by using hierarchical analysis method (AHP) and fuzzy comprehensive evaluation method (FCE), and establishes an evaluation system for comprehensively assessing the depletion of the ores. The results show that structural parameters, blasting parameters, loading parameters, and geological conditions are the main factors affecting ore depletion. The structural parameters are the most important factors, accounting for 35%. With the increase of the released amount, the released grade gradually decreases, the depletion rate gradually increases, and the comprehensive evaluation value gradually decreases. The released body is an approximate ellipsoidal block with a wide upper and narrower lower part. The end wall plays an obstructive role in the flow of the bulk body, which makes the end of the released grade higher and the middle of the released body higher. At the same time, due to the influence of blasting and shovel loading, the particles in the release body show some sorting phenomena. This paper provides a scientific basis and reference for predicting and controlling ore depletion in the bottomless column segmental chipping method. [ABSTRACT FROM AUTHOR]

This case study utilizes data from the Roy Hill iron ore mine, which has a daily water balance of abstraction, use, and surplus disposal, to address the problem of water management prediction at a global level by analysing the results of each modelling task and evaluating the presence of potential critical scenarios with an automated, mathematically rigorous tool. This paper describes the development of a software application that aggregates the results of the various water management models built for each task and provides the optimal utilisation of water to minimise water disposal and thereby maximise water usage. The business benefits of this work include the ability to calculate the net present cost (NPC) for new water infrastructure configurations in an integrated way. Investing in capital projects for water management and evaluating various scenarios helps determine the optimal water infrastructure configuration, minimizing operational impact. Traditionally, water has not been viewed as a significant cost; however, the cost of water infrastructure is now one of the highest business investments in the mining industry of the Pilbara region of Western Australia. Introducing the concept of NPC for water in the mining industry is a novel approach to making informed decisions on water expenses and investments. The key to success lies in using automated modelling to achieve the most efficient environmental and operational balance. This approach reduces individual decision-making and leads to a more cost-effective and beneficial production outcome. [ABSTRACT FROM AUTHOR]

Relying on Chinese county gazetteers and contemporary publications by Western engineers working in China, this article examines the methods used by county officials to secure property needed for the Daye iron mine in Hubei Province. It focuses on a young scholar-turned magistrate, Lin Zuo, who grew up around the market city of Shanghai and the political center in Beijing under the dual clouds of imperialism and the Taiping Rebellion. Upon taking office in a remote but mineral-rich county along the Yangzi river, Lin Zuo was deputed to deterritorialize significant parts of the county's rice fields and mountain farms to facilitate a modern iron ore mine and adjoining railroad that became part of the powerful Hanyeping Coal and Iron Company. To this end, he hired local gentry to coerce or force various landowners to give up lands that were deemed rich in minerals or suited for a proposed train track that skirted the southern face of Tieshan (Iron Mountain). Conversely, commoners utilized ingenious negotiating methods to fight back against the power of the imperial government, which led the county leaders to look elsewhere for properties and in some cases forced the government to pay much higher prices for the tracts they needed most. This article suggests that this significant modernization scheme was brought about in part utilizing the trappings of patronage-led county government policies but that even as it was designed to strengthen the empire, in fact it actually weakened the local community, leaving many landless if not impoverished. It therefore questions recent scholarship that looks more positively at late nineteenth-century industrialization attempts or critically at policies that undermined them. [ABSTRACT FROM AUTHOR]

In the coal and mineral beneficiation industries, screening is one of the crucial physical separation methods carried out to separate the undersized fine particles from the oversize coarse particles. The vibratory screener is a relatively advanced screening technology applied for coal and iron ore beneficiation. This paper deals with the experimental investigation for assessing the efficiency of screening coal and iron ore in the vibratory screener. Furthermore, a comparative study between the test performance of screening coal and iron ore was carried out depending on moisture and density variation. Test results show that the vibratory screener can provide a high recovery of fines and increased efficiency for screening iron ore than coal material. The maximum efficiency of iron ore was attained at a higher angular position, such as 3 and 5 degrees in an upward slope, whereas the maximum efficiency of coal was attained at 1 degree in an upward slope. [ABSTRACT FROM AUTHOR]

Copyright of ANIAV: Revista de Investigación en Artes Visuales is the property of Universidad Politecnica de Valencia and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Revista Brasileira de Engenharia Agricola e Ambiental - Agriambi is the property of Revista Brasileira de Engenharia Agricola e Ambiental and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

In sulphur-coal symbiotic coal seams, after the mining of sulphide iron ore, when the coal resources are mined, the mine water accumulated in the roadway mining area will have a certain impact on the stability of the surrounding rock of the coal seam roadway. Taking the floor sandstone of sulfur coal symbiotic coal seam as the research object, the roof fissure water with pH values of 7.48, 4.81 and 2.62 was used as the experimental solution. 10 experimental schemes were designed to measure the compressive strength of the samples under the action of AMD, and the hydrochemical analysis of AMD was conducted. The pore structures of the samples before and after the action of AMD were analyzed. Based on the hydrochemistry and pore structure, the deterioration mechanism of compressive strength of the coal seam floor sandstone under the action of AMD was explained. The results indicated that the compressive strength of the samples decreased with the increasing action time of AMD. The compressive strength decreased with the increment of the porosity. The concentration of H+ ion in AMD was relatively small. Na2O in albite dissolved and reacted with water, leading to an increase in the concentration of Na+ ion. Soluble substances such as MgCl2 and CaSO4 in the pore structure dissolved, leading to an increase in the concentration of Ca2+ and Mg2+ ions. The dissolution of soluble substances and the physical–chemical reactions between solutions and minerals were the essential causes of the continuous deterioration of the compressive strength of the coal seam floor sandstone. The results of this study can provide a theoretical basis for the deterioration of the mechanical properties of the peripheral rock in the roadway of the sulphur coal seam, and can also provide a certain engineering reference for the sulphur coal seam roadway. [ABSTRACT FROM AUTHOR]

Tibetans have a long history of iron mining, smelting, and forging. For centuries, craftsmen in major cities and large iron production centers made high-quality swords and suits of armor, as well as decorative iron ritual objects for monasteries and the elites, but blacksmithing workshops in small villages have always produced and repaired everyday objects for agricultural and home use. Modern political changes, along with greater availability of industrial objects in local markets, have greatly reduced the rank of the village blacksmith. Ethnographic fieldwork reported here from two Tibetan Bön villages in the Aba Tibetan and Qiang Autonomous Prefecture, China (once part of traditional Amdo area of Tibet), highlights some of the threats to the continued existence of village blacksmiths. Both a part-time blacksmith in one village and a full-time blacksmith in another make only a marginal living from their work. Their descendants are unlikely to continue the business. Many of the village blacksmiths in the area have already stopped production and closed their workshops. It is likely that the village blacksmith tradition might soon disappear altogether in this region of the world without support. Preservation of this tradition could benefit both cultural and environmental sustainability goals. [ABSTRACT FROM AUTHOR]