Local Mining Research Articles

Coal Mine Dust Size Distributions, Chemical Compositions, and Source Apportionment

Current regulations mandate the monitoring of respirable coal mine dust (RCMD) mass and crystalline silica in underground coal mines to safeguard miner health. However, other RCMD characteristics, such as particle size and chemical composition, may also influence health outcomes. This study collected RCMD samples from two underground coal mines and performed detailed chemical speciation. Source apportionment was used to estimate RCMD and silica contributions from various sources, including intake air, fire suppression limestone dust, coal dust, diesel engine exhaust, and rock strata. The mine dust mass-based size distributions were comparable to those recorded over a decade ago, with a peak around 10 μm and the majority of the mass in the supermicron size range. The current mine conditions and mining practices do not appear to have significantly increased the generation of smaller particles. Limestone rock dust was prevalent in many locations and, along with coal dust, was the main contributor to RCMD at high-concentration locations. Silica accounted for over 10% of RCMD mass at several active mining locations, primarily from limestone and rock strata dust. Reducing the concentration of limestone dust and its silica content could reduce RCMD and silica levels. Further cleaning of the intake air could also improve the overall mine air quality.

Microbial Inoculants Modify the Functions of Resident Soil Microbes to Expedite the Field Restoration of the Abandoned Mine

ABSTRACTGlobal‐scale mining activities have had significant deleterious impacts on local ecosystems and the overall environment, which will necessitate robust restoration efforts. A practical approach includes combining microbial inoculants with the technology of external soil spray seeding. This approach holds the potential for sustainable abandoned mine site restoration by enhancing plant growth through the modulation of soil nutrients and microbial communities. Nonetheless, the detailed effects of microbial inoculants on specific aspects of soil microbial community functions and their complex interactions with plant growth remain underexplored, particularly in the context of restoration efforts. To bridge this gap, we performed a four‐year field study at an abandoned carbonate mine location, using metagenomic sequencing to evaluate the influence of microbial inoculants on soil microbial functionality. Our research revealed that introducing microbial inoculants greatly enhanced essential soil parameters and notably increased plant biomass. Additionally, these inoculants altered the functional gene makeup of the microbial community, significantly boosting the relative abundance of processes such as nitrogen fixation, nitrification, denitrification, assimilatory nitrate reduction (ANRA), dissimilatory nitrate reduction (DNRA), and organic phosphorus mineralization. Conversely, there was a decrease in the relative abundance of carbon degradation, phosphorus regulation, and transport processes. We observed strong correlations between the abundance of nitrogen and phosphorus cycles and plant biomass. Crucially, microbial inoculants affect plant biomass by initially altering soil properties and subsequently coordinating nitrogen and phosphorus cycles. These findings provide valuable insights into the role of microbial inoculants in mine site restoration and offer a theoretical foundation for their broader practical application.

Influence of different mining locations on deformation characteristics of overlying strata on gently anti-dip high-steep mining slope.

High-steep gently inclined mining slopes, prevalent globally, often suffer significant deformation, leading to landslides due to numerous goafs. This research investigates the critical role of goaf location in controlling deformation, failure mechanisms, and disaster evolution, vital for safe mining practices. Through field investigations and model generalization in Guizhou, a physical model test method was used to study three positions of goafs: under the shoulder and foot of the slope, under the slope shoulder, and within the slope. Findings highlight the stronger influence of the goaf's mutual position with the slope shoulder on slope and overburden deformation and failure compared to the slope toe. Deformation and failure modes evolve from collapse toppling to collapse slip and collapse settlement as the goaf shifts from the near slope surface to inside of the slope. Statistical analysis of fracture distribution in the goaf's overlying strata reveals damage increase with larger goafs, following a Gaussian distribution, with concentrated damage in the middle. The study identifies the maximum damage area, influenced by the horizontal distance between the goaf center and slope shoulder. These insights advance understanding of overburden rock deformation in gently inclined high-steep mining slopes.

Mining struggles in north-central Mexico: Between mining tradition, poverty, and environmentalism

The present study is centered on characterizing the conflicts associated with mining in Sonora and Zacatecas, two states in north-central Mexico. We consider the municipal surroundings where they emerge, via cartographical analysis of some variables including mining frontiers and poverty. The predominant conflict types show that communities are not inclined to accept mining as presented in government or corporate discourses; rather, communities struggle to improve their living conditions and preserve their natural surroundings. We can observe that in long-time mining locations, there is greater acceptance of the mining industry, so that the conflicts which arise tend to be concerned with labor or with eco-territorial matters of coexistence and pecuniary assets, although there are also alternatives; meanwhile, in places with recent mining penetration and deep-rooted agro-fisheries activities, conflicts tend to be eco-territorial regarding alternatives and territorial defense. However, the advance of the mining frontier configures the coexistence of different temporal regimes, based on complex spatio-temporal patterns where different types of environmentalism overlap with demands for opposition, negotiation, or collaboration in the same place.

ORGANOPHILIC BENTONITES OF UKRAINE. 1. SCIENTIFIC PRINCIPLES OF PRODUCTION. THE MECHANISM OF ORGANOPHILIZATION OF THE SURFACE

In connection with the inevitable integration of Ukraine into the EU and the discovery of new deposits of high-quality bentonite clays in Ukraine, the issues of studying, developing and industrially producing organophilic bentonites — analogues of foreign trademarks Bentone, Geltone, Petrotone — are becoming especially relevant. Without structuring additives of such bentones, the normal functioning is impossible of the most important industries: automotive, paint and varnish, petrochemical, oil producing, rubber, foundry, mechanical engineering, cosmetics, etc. This work is intended for the first time in Ukraine to lay the scientific foundations for obtaining such materials based on local mineral raw materials. For this purpose, the adsorption of a number of cationic surfactants (quaternary alkylammonium salts) on 4 montmorillonites of bentonite deposits in Ukraine and its effect on the stability, electrosurface and rheological properties of mineral aqueous dispersions were studied. Based on the obtained X-ray data and the dependences of adsorption, z-potential and yield point of dispersions on the concentration of surfactants, the mechanism of surface organophilization was clarified and optimal conditions for modifying montmorillonites for obtaining structure-forming agents for organic media were determined. It was shown that montmorillonite from the Neporotovskoye deposit is the most promising for this purpose. Bibl. 48, Fig. 12, Tab. 6.

AnnoDUF: A Web-Based Tool for Annotating Functions of Proteins Having Domains of Unknown Function.

The rapid expansion of biological sequence databases due to high-throughput genomic and proteomic sequencing methods has left a considerable number of identified protein sequences with unclear or incomplete functional annotations. Domains of unknown function (DUFs) are protein domains that lack functional annotations but are present in numerous proteins. To address the challenge of finding functional annotations for DUFs, we have developed a computational method that efficiently identifies and annotates these enigmatic protein domains by utilizing the position-specific iterative basic local alignment search tool (PSI-BLAST) and data mining techniques. Our pipeline identifies putative potential functionalities of DUFs, thereby decreasing the gap between known sequences and functions. The tool can also take user input sequences to annotate. We executed our pipeline on 5111 unique DUF sequences obtained from Pfam, resulting in putative annotations for 2007 of these. These annotations were subsequently incorporated into a comprehensive database and interfaced with a web-based server named "AnnoDUF". AnnoDUF is freely accessible to both academic and industrial users, via the World Wide Web at the link http://bts.ibab.ac.in/annoduf.php. All scripts used in this study are uploaded to the GitHub repository, and these can be accessed from https://github.com/BioToolSuite/AnnoDUF.

Special Issue: 100 years of scientific excavations at UNESCO World Heritage Site Monte San Giorgio and global research on Triassic marine Lagerstätten

Only a few Swiss fossil localities are known globally and of which, the UNESCO World Heritage Site Monte San Giorgio, which extends from Switzerland into Italy, is the most important one. Following the discovery of the occurrence of articulated skeletons of marine reptiles in the local mines, large excavations were organized by Bernhard Peyer from the University of Zurich starting 1924. With this collection of articles, we commemorate the successful excavations and research, which initiated the publication of a series of monographies, mostly on the vertebrates but also on the invertebrates of this locality. Especially with the discovery of several remarkably similar Konservat-Lagerstätten in China, the discoveries from Monte San Giorgio gained global relevance. New methodologies such as computed tomography produced a wealth of new data, particularly on endocranial anatomy of several tetrapods.

The environmental consequences of rapid urbanization in central Florida reconstructed with high resolution 241Am and 210Pb dating in lake sediments

Throughout the 20th century, Florida was one of the fastest growing states in the US, putting unique environmental stress on the region. Accurately dated lake sediments can provide invaluable records of environmental change that extend beyond monitoring records. Here, we analyze profiles of americium-241 (241Am), cesium-137 (137Cs), lead (Pb), zinc (Zn), and uranium-series radionuclides in Lake Bonny in Lakeland, Florida. The 241Am peak is sharp in the sediment profile, while the 137Cs peak is broader and spread evenly across two layers. The measured 137Cs inventory of ~448Bq/m2 is less than half of the expected inventory from atmospheric deposition (accounting for decay since deposition), indicating significant losses. The reliability of 137Cs as a chronological tool can be complicated in environments with low quantities of 2:1 clays and low available potassium (K), characteristic of Florida and the U.S. southeast. Using a piecewise constant rate of supply 210Pb model verified by 241Am, we reconstruct sedimentation and chemical change in this lake. Highest sedimentation rates in the lake occur during decades of peak population growth in the mid-20th century. Uranium (U) and radium-226 (226Ra) inputs to the lake reach a maximum in the 1960s, consistent with expansion of local phosphate mines and elevated groundwater pumping during that time in response to drought conditions. Total Pb in the sedimentary record captures the rise and fall of the use of leaded gasoline, but Zn inputs to the lake remain nearly two orders of magnitude above background levels in the last decade. Our high-resolution chronology of the lake reveals regional impacts on water and lake quality in central Florida during a period of rapid population growth.

Simultaneous co-assembly of collagen and glycosaminoglycans to build a biomimetic extracellular matrix for bone regeneration

Glycosaminoglycans (GAGs), also known as shape modules, are considered junctions that help define the shape of collagen matrix and further promote mineralization during osteogenesis. Many attempts have been made to immobilize GAGs on assembled collagen to modify the latter's surface state. However, it remains unclear how GAGs spontaneously identify collagen molecules during fibrillogenesis in vivo. Understanding the relationship between GAGs and collagen from both the bone physiology and materials science perspectives is of fundamental interest. Here, we introduced hyaluronic acid (HA, a main member of GAGs) during collagen self-assembly, in a process called modification cooperating with self-assembly (MCS). The molecular docking and morphological studies revealed that HA can help define collagen monomer deposition and thus promote fibrillogenesis through steric hindrance or by directly forming hydrogen bonds. Meanwhile, HA acts as a templating chaperone (TC) to increase the local mineral concentration within intrafibrillar channels but does not initiate nucleation, thus improving the crystallinity of formed apatite. The scaffolds synthesized through MCS model significantly improved the physicochemical stability and mechanical strength of collagen-based scaffolds. The optimized scaffolds promoted in-situ osteogenesis by stimulating the osteogenic differentiation of bone mesenchymal stem cells, either in an osteogenic medium, or after implantation into critical calvarial defects. This study provides novel insights towards evolving engineering scaffolds from inert supports to functional substitutes.

Bench scale and pilot plant flotation tests with phosphate rock from the Alto Paranaíba Region/MG, Brazil

This paper highlights the significant advances in phosphate recovery in the Alto Paranaíba region, Minas Gerais, as a result of collaboration between RJMG and the local mining industry. The applied methodology focused on the development and use of the innovative AGEM B plant collector, going from laboratory tests to pilot plant tests. The results demonstrated the superiority of AGEM B compared to standard collectors, where a 14.1% increase in P2O5 recovery and a 40% reduction in collector dosage were observed. On a pilot scale, the average P2O5 content in the rougher tailings was 1.66 ± 0.29%, 38.40% lower than that obtained with the collector used by the mining company (a fatty acid) which presented an average content of 2.69 %. The average P2O5 content in the recleaner concentrate was 32.15 ± 2.59%, 8.27% higher than that obtained with fatty acid (average of 35.05%). Increases of 43.59% in mass recovery (average of 11.20 ± 1.31%) and 36.28% in metallurgical recovery (average of 71.00 ± 4.82%) were observed. This work highlights the importance of innovation and strategic collaboration to overcome challenges in mineral processing, recommending the use of AGEM B on an industrial scale for better efficiency and sustainability in the phosphate recovery process.

Spatio-temporal differentiation characteristics of coal mine safety levels in China based on spatial spillover effects

In order to solve the problem of "potpourri" of safety risk prevention and control measures, which is caused by the unclear mechanism of the spatial effect of coal mine safety level heterogeneity and its influencing factors. This paper discriminates the dominant factors of spatio-temporal heterogeneity of coal mine safety production level in China and their spatial effect types by means of GeoDetector and the Spatial Dubin Model (SDM), specifies the categories and degrees of acts on local and surrounding areas by changes in indicators, and provides further visualization of the detection outcomes with the assistance of the Neo4j graph database, and the findings indicate that:(1) All 15 indicators selected in the study have a certain influence on the generation of spatial heterogeneity in China's coal mine safety production level, and all of them show an enhancement relationship after the interaction of indicators. Especially, the combination of excavated environment and other indicators basically has a non-linear enhancement relationship. (2) In terms of spatial effects, the influence of the 5 effects on the spatio-temporal heterogeneity of coal mine safety level is, in descending order, industrial development effect > capital allocation effect > production environment effect > government supervision effect > enterprise management effect, which indicates that macroeconomic and market conditions have a much stronger influence on the generation of spatio-temporal heterogeneity in coal mine production safety status. (3) From the single indicator perspective, the average annual temperature, average annual wind speed, coal consumption and monitoring efficiency primarily affect the dependent variable through direct effects; GDP per capita, average labor compensation as well as railroad operating mileage have positive spatial spillover on the changes of coal mine safety production level in surrounding areas; the evaluation of the spatial effect for average labor compensation exhibits a positive indirect effect with low influence; for the two indicators of production efficiency and ex-factory price, not only do they have negative effects on the local coal mine safety level, but also have significant spillover effects on surrounding areas.

New Discovery of Natural Zeolite-Rich Tuff on the Northern Margin of the Los Frailes Caldera: A Study to Determine Its Performance as a Supplementary Cementitious Material.

The release of Neogene volcanism in the southeastern part of the Iberian Peninsula produced a series of volcanic structures in the form of stratovolcanoes and calderas; however, other materials also accumulated such as large amounts of pyroclastic materials such as cinerites, ashes, and lapilli, which were later altered to form deposits of zeolites and bentonites. This work has focused on an area located on the northern flank of the San José-Los Escullos zeolite deposit, the only one of its kind with industrial capacity in Spain. The main objective of this research is to characterize the zeolite (SZ) of this new area from the mineral, chemical, and technical points of view and establish its possible use as a natural pozzolan. In the first stage, a study of the mineralogical and chemical composition of the selected samples was carried out using X-ray diffraction (XRD), scanning electron microscopy (SEM), X-ray fluorescence (XRF), and thermogravimetric analysis (TGA); in the second stage, chemical-qualitative and pozzolanicity technical tests were carried out at 8 and 15 days. In addition, a chemical analysis was performed using XRF on the specimens of mortars made with a standardized mixture of Portland cement (PC: 75%) and natural zeolite (SZ: 25%) at the ages of 7, 28, and 90 days. The results of the mineralogical analyses indicated that the samples are made up mainly of mordenite and subordinately by smectite, plagioclase, quartz, halloysite, illite, and muscovite. Qualitative chemical assays indicated a high percentage of reactive silica and reactive CaO and also negligible contents of insoluble residues. The results of the pozzolanicity test indicate that all the samples analyzed behave like natural pozzolans of good quality, increasing their pozzolanic reactivity from 8 to 15 days of testing. Chemical analyses of PC/SZ composite mortar specimens showed how a significant part of SiO2 and Al2O3 are released by zeolite while it absorbs a large part of the SO3 contained in the cement. The results presented in this research could be of great practical and scientific importance as they indicate the continuation of zeolitic mineralization beyond the limits of the San José-Los Escullos deposit, which would result in an increase in geological reserves and the extension of the useful life of the deposit, which is of vital importance to the local mining industry.

Hydrogeochemical characteristics and agricultural suitability of shallow groundwater quality in a concentrated coalfield area of Huaibei Plain, China.

Groundwater is one of the chief water sources for agricultural activities in an aggregation of coal mines surrounded by agricultural areas in the Huaibei Plain. However, there have been few reports on whether mining-affected groundwater can be adopted for agricultural irrigation. We attempted to address this question through collecting 71 shallow groundwater samples from 12 coal mining locations. The Piper trilinear chart, the Gibbs diagram, the proportional coefficient of major ions, and principal component analysis were examined to characterize the source, origin, and formation process of groundwater chemical composition. The suitability for agricultural irrigation was evaluated by a final zonation map that establishes a comprehensive weighting model based on analytic hierarchy process and criteria importance though the intercriteria correlation (AHP-CRITIC). The results revealed that the groundwater was classified as marginally alkaline water with a predominant cation of HCO3- and anion of Na+. Total hardness, total dissolved solids, sulfate (SO42-), sodium (Na+), and fluoride (F-) were the primary ions that exceeded the standard. The results also indicated that the dominant hydrochemical facies were Ca-HCO3 and Na-Cl. The dissolution of carbonate, silicate, sulfate minerals, along with cation exchange, were the main natural drivers controlling the hydrogeochemical process of groundwater. The zonation map suggested that 43.17%, 18.85%, and 37.98% of the study area were high, mediate, and low suitability zones, respectively. These results from this study can support policymakers for better managing groundwater associated with a concentration of underground coal mines.

Perlindungan Hukum Terhadap Masyarakat Di Wilayah Pertambangan Dalam Penyelesaian Sengketa Pengelolaan Lingkungan Hidup

Mining activities that are increasingly uncontrolled have various impacts on the community and life around the mine, including; Environmental damage, high levels of pollution (soil, water and air), also cause disruption to the wider community in the form of damage to houses and public facilities. This research aims to determine the form of legal protection for communities in mining areas who suffer losses related to mining activities, as well as to determine dispute resolution in the form of demands for compensation from communities around mining locations. The research method uses normative research methods with a statutory approach, conceptual approach and case approach. Apart from that, empirical research is also used to see the reality that occurs in the field. The results of the research show that the legal implications regarding the protection of communities in mining areas in environmental management are problematic in their resolution due to the government's indifference and also regarding the compensation provided by mining business actors. The responsibility for restoring mining land is the responsibility of business actors as an obligation to restore the social and economic environment as a result of the impact of mining activities on communities in mining areas.

Regolith-Hosted Rare Earth Element Mineralization in the Esperance Region, Western Australia: Major Characteristics and Potential Controls

A number of regolith-hosted REE occurrences have recently been discovered in the Esperance region in southern Western Australia. This paper summarizes major characteristics of REE mineralization and discusses contributing factors and potential controls. The main aim is to explain why there is a lack of highly sought-after ion-adsorption-clay-type REE deposits across the region despite the presence of the regolith-hosted REE mineralization on a regional scale. Local mineralization mostly occurs as continuous flat-lying enrichment “blankets” within the residual regolith developed over Archaean–Proterozoic granite gneisses and granitoids with elevated REE content. The enriched horizon is commonly located in the lower saprolite and saprock and is accompanied by an overlying REE-depleted zone. This distribution pattern, together with the data on HREE fractionation and the presence of the supergene REE minerals, indicates chemogenic type enrichment formed by supergene REE mobilization into groundwater, downward transport, and accumulation in the lower part of the weathering profile. Residual REE accumulation processes due to bulk rock volume and mass reduction during weathering also contribute to mineralization. It is proposed that climate and groundwater chemistry are the critical regional controls on the distribution of REEs in the weathering profile and on their speciation in the enrichment zone. Cenozoic aridification of climate in southwest Australia heavily overprinted pre-existing REE distributions in the weathering profile. Acidic (pH < 4), highly saline groundwaters intensely leached away any relatively weakly bound, adsorbed or colloidal REE forms, moving them downward. Dissolved REEs precipitated as secondary phosphates in neutral to alkaline environment at lower Eh near the base of the weathering profile forming the supergene enrichment zone. Low denudation rates, characteristic of areas of low relief under the arid climate, are favourable for the preservation of the existing weathering profiles with REE mineralization.

Understanding the Perspective of the Mining-Affected Community on Illegal Gold Mining (PETI) in Gogorea Village, Waeapo District, Buru Regency

This research aims to understand the perspectives of mining communities on illegal gold mining (PETI). They conducted their study in Gogorea Village, Waeapo District, and Buru Regency, using a qualitative method with theoretical foundations to grasp community perspectives. Sampling was done through simple random sampling involving 12 respondents: Village Heads, five local miners, and six non-local miners. Data were collected through observation, interviews, and documentation, then analyzed descriptively using the Likert scale. The results reveal the unique characteristics of PETI in Gogorea Village, where miners use simple and traditional tools, often collaborate, and employ traditional gold refining methods. Although PETI provides income, its severe environmental impacts, including waste, soil, forest, and air pollution, are evident. Ecological protection is necessary for sustainability and community welfare. It is recommended to enforce strict regulations and increase monitoring of PETI activities to mitigate environmental damage. Additionally, providing sustainable economic alternatives for communities is crucial to reducing dependence on illegal mining.

Artificial bee colony optimization algorithm with full dimensional updating strategy and its application

For the low accuracy and slow convergence speed of artificial bee colony(ABC) algorithm in solving complex optimization problems, an improved artificial bee colony(ABC) algorithm based on the new full dimensional updating ABC/best /1 strategy, namely FNABC was proposed in this paper. In the FNABC, for the low efficiency of one-dimensional search, the full dimensional updating search strategy and ABC/best /1 strategy were combined to design a new full dimensional updating ABC/best/1 strategy, which expanded the search space, improved the mining ability and search efficiency. Then, a new evolutionary phase is designed to balance the global search ability and local mining ability to avoid falling into local optimum and improve the convergence accuracy. Finally, the FNABC is compared with eight state-of-the-art ABC variants such as AABC, iqABC, MEABC, ABCVSS, GBABC, DFSABC, MABC-NS, MGABC in solving 12 complex functions. All functions have obtained the best optimal values among 9 algorithms. Additionally, FNABC is applied to solve a real-world train operation adjustment problem. The experiment results indicate that the FNABC has better optimization ability, scalability and robustness. It obtains the ideal train operation adjustment results.

Climate policy stringency and trade in energy transition minerals: An analysis of response patterns

Climate policies directly affect cleaner energy technology markets, affecting price signals for greener electricity production. In turn, the manufacturing of energy technologies relies heavily on mineral inputs, posing challenges in securing mineral ores and concentrates either from local mines or overseas. This paper contributes to the mineral-energy literature by examining the impact of climate change policies on the net import demand for five essential minerals used in cleaner energy technologies: copper, aluminium, nickel, cobalt, and manganese. We examined country-level panel data from 33 countries from 1992 to 2015 to understand patterns in net imports relative to renewable generation. This metric allows the examination of technological improvements that contribute to more efficient use of imported mineral inputs in renewable energy systems. Results suggest that while both net import volumes and renewable generation have increased over time, net imports per renewable generation have continuously declined on average, suggesting that nations may have efficiently utilized imported resources to generate more than proportionate increases in cleaner energy. Moreover, results from a cross-sectional autoregressive distributed lag model show that the stringency of environmental policies significantly affects net mineral imports per renewable generation, with marked variations across minerals and countries. Notably, with stricter policies, import reliance on cobalt and aluminium per renewable energy increases in the short run and eventually declines in the long run. Import reliance for copper declines per unit of renewable energy in the short run but increases in the long run. These findings emphasize the need for tailored policies to navigate mineral trade dynamics effectively. The research contributes valuable insights to the ongoing discussions surrounding sustainable energy transitions and global mineral trade patterns.

Implications of Water Quality Index and Multivariate Statistics for Improved Environmental Regulation in the Irtysh River Basin (Kazakhstan)

The selection of sites for permanent environmental monitoring of natural water bodies should rely on corresponding source apportionment studies. Tools like the water quality index (WQI) assessment may support this objective. This study aims to analyze a decade-long dataset of measurements of 26 chemical components at 26 observation points within the Irtysh River Basin, aiming to identify priority zones for stricter environmental regulations. It was achieved through the WQI tool integrated with geoinformation systems (GISs) and multivariate statistical techniques. The findings highlighted that both upstream sections of tributaries (Oba and Bukhtarma rivers) and the mainstream of the basin are generally in good condition, with slight fluctuations observed during flooding periods. Areas in the basin experiencing significant impacts from mining and domestic wastewater treatment activities were identified. The rivers Glubochanka (GL) and Krasnoyarka (KR) consistently experienced marginal water quality throughout the observation period. Various contaminant sources were found to influence water quality. The impact of domestic wastewater treatment facilities was represented by twofold elevated concentrations of chemical oxygen demand, reaching 22.6 and 27.1 mg/L for the KR and GL rivers, respectively. Natural factors were indicated by consistent slight exceedings of recommended calcium levels at the KR and GL rivers. These exceedances were most pronounced during the cold seasons, with an average value equal to 96 mg/L. Mining operations introduced extremal concentrations of trace elements like copper, reaching 0.046–0.051 mg/L, which is higher than the threshold by 12–13 times; zinc, which peaked at 1.57–2.96 mg/L, exceeding the set limit by almost 50–100 times; and cadmium, peaking at levels surpassing 1000 times the safe limit, reaching 0.8 mg/L. The adverse impact of mining activities was evident in the Tikhaya, Ulba, and Breksa rivers, showing similar trends in trace element concentrations. Seasonal effects were also investigated. Ice cover formation during cold seasons led to oxygen depletion and the exclusion of pollutants into the stream when ice melted, worsening water quality. Conversely, flooding events led to contaminant dilution, partially improving the WQI during flood seasons. Principal component analysis and hierarchical cluster analysis indicated that local natural processes, mining activities, and domestic wastewater discharge were the predominant influences on water quality within the study area. These findings can serve as a basis for enhanced environmental regulation in light of updated ecological legislation in Kazakhstan, advocating for the establishment of a comprehensive monitoring network and the reinforcement of requirements governing contaminating activities.

Planning Optimization of a Standalone Photovoltaic/Diesel/Battery Energy System for a Gold Mining Location in Mauritania

Planning Optimization of a Standalone Photovoltaic/Diesel/Battery Energy System for a Gold Mining Location in Mauritania