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The study of the mineralogical and geochemical features of placer gold and the mechanisms of its distribution in the territory east of the Siberian platform, overlain by a thick cover of Mesozoic–Cenozoic deposits, where traditional methods of searching for gold fields are not effective, allowed researchers, for the first time, to establish the stages of ore formation and to predict the types of gold deposits and their location. The identified indicators of placer gold (morphology, granulometry, chemical composition, micro-inclusions, and internal structures) indicate that ore occurrences in both the Precambrian and Mesozoic stages of ore formation were primary sources of placer gold. The identification of characteristic indicators in placer gold for certain types of gold deposits allowed researchers to prove the formation of gold ore sources east of the Siberian platform for the first time: low-sulfide quartz gold, gold–ferruginous quartzite, gold–copper–porphyry, and gold–platinoid formations are found in the Precambrian stage of ore formation and gold–silver, gold–sulfide–quartz, and gold–rare metal formations are found in the Mesozoic stages of ore formation. Thus, for the first time, based on a huge amount of factual material, it is proved that the mineralogical and geochemical features of placer gold carry enormous information about both the endogenous origin of gold (stages of ore formation—Precambrian and Mesozoic) and the expected type of formation of the predicted deposits. It is established that the predicted type of ore sources corresponds to a certain geological and structural position; this contributes to a more correct selection of methods for searching for ore and placer gold deposits in closed territories and assessing their prospects. In general, the application of the mineralogical method for the first time makes it possible to develop criteria for predicting resources and types of gold deposits, and to assess the prospects of gold mining potential in platform areas at a new level of knowledge. [ABSTRACT FROM AUTHOR]

Hydrometallurgical gold recovery processes play a pivotal role in the gold mining industry, contributing to more than 90% of global gold production. Among the array of techniques available, the Merrill–Crowe process, adsorption, ion exchange, and solvent extraction are central in extracting gold from leach solutions. While the Merrill–Crowe process and gold complex adsorption onto activated carbon represent historical cornerstones, their inherent limitations have prompted the emergence of more recent innovations in ion exchange and solvent extraction, offering enhanced selectivity, control, and sustainability. The evolution of modern organic chemistry has significantly influenced the progress of ion exchange technology, mainly through the introduction of advanced polymer matrix synthetic resins. At the same time, novel solvents tailored to gold complex interactions have revitalized ion exchange and solvent extraction. Introducing ionic liquids and deep eutectic solvents has also added a new dimension to efforts to improve gold extraction metallurgy. This paper reviews these cutting-edge developments and their potential to revolutionize the hydrometallurgical gold recovery process, addressing the pressing need for improved efficiency and environmental responsibility. [ABSTRACT FROM AUTHOR]

The introduction of mercury (Hg) into the environment by anthropogenic activities has resulted in negative implications for ecosystem functions and human health. Unlike the legacy of huge environmental pollution left by historic gold rushes in several developed countries, gold-rich nations in the developing world are currently witnessing what could qualify as a "new gold rush", conducted primarily by small-scale mining operators and characterized by the use of metallic Hg (Hg0) in the amalgamation process to extract gold from crude ores. Once introduced into the environment, Hg0 can undergo biogeochemical transformations to produce Hg species such as methyl-Hg, with well-established adverse impacts on living organisms. This review summarizes published data on both historical and recent trends of the use of Hg0 in artisanal gold mining (AGM) on a global scale and emphasizes the impacts of AGM on the environment. To achieve this, we used citations from research conducted in North and South America, Europe, Asia, Africa, Australia, and New Zealand, obtained from several search engines and databases. Our findings show that, in addition to the well-known environmental and human health adverse effects of gold mining with Hg0, gold extraction by the Hg amalgamation technique is boosting the economy in parts of Africa, South America, and Asia. Unfortunately, this appealing aspect of AGM may not be easily halted, pending the creation of alternative employment. Therefore, there is a clear need for the development of safe and affordable gold extraction and purification technologies. Ultimately, the growth of this specific economic sector should be regulated to help protect both the environment and human health. Information compiled in this review should help to (i) improve the mapping of AGM-impacted soil and aquatic systems on a global scale and (ii) stimulate discussions and research on how to take down current barriers to the development and implementation of safe AGM methods. [ABSTRACT FROM AUTHOR]

The identification of trace element anomalies in soils has been proven to assist semi-mechanized small-scale gold operations. This study employs soil geochemistry combined with the microchemical signature of particulate gold from the Batouri goldfield to (1) vector possible gold-endowed lithologies introducing particulate gold into the overlying regolith, and (2) assess anthropogenic Hg used in purification of both primary and alluvial/eluvial gold by artisans. The soil geochemistry shows irregularly distributed anomalies of elevated Cu especially in the saprolite soil layer. Whereas in the lateritic soil layer, a Au-Ag-Hg metal association is reported for the first time in this gold district and could be linked to anthropogenic Hg used in gold recovery. Particulate gold recovered from the soil varies in shape from euhedral and irregular to sub-rounded, indicating a proximal lode source. The gold grains range in size from nano-particles to >300 µm and are Au-Ag alloys. The gold particles reveal inclusions such as quartz, silicate, zircon and ilmenite suggesting that the grains were dislodged from quartz veins within the granitic basement. Systematic variation in the microchemical signature of the gold grains is suggestive of spatial and temporal evolution of the mineralizing fluid. These results are consistent with investigations from similar geologic settings worldwide and validate the combined utility of gold fingerprinting and pathfinder elements in soil to examine deposit genesis in other gold districts globally. [ABSTRACT FROM AUTHOR]

Acid mine drainage (AMD) prevention or remediation is a major issue of the environmental management of sulfide-bearing active and abandoned mining sites, the main sources of acidic waters being wastes and tailings. The present work intends to check a circular economy approach to such issues in the mining region of Sardinia, where environmental pollution, due to AMD, is a major concern. Tests were conducted on basic drainage-producing feldspar mining wastes that could be recycled as buffering agents of sulfide-bearing tailings. Among the sulfide-bearing abandoned mining sites investigated, Furtei epithermal gold deposit tailings are the most polluting and those that can better test the buffering agent efficacy. Buffering test results show that buffering to near-neutral conditions can be attained following steps similar to those of pure calcite buffer. The buffering potential of the recycled waste is due to both the buffer calcite content, which provides short-term buffering, enhanced by feldspar content that can provide long-term buffering. Buffered waters show a dramatic decrease in the concentration of most of the metals present in the leachate, down to conditions that meet the requirements for the discharge of industrial waters according to Italian legislation. [ABSTRACT FROM AUTHOR]

The processing of aeromagnetic data was carried out in Northern Cameroon, with the aim of delineating the structural features which may be associated with the gold occurrence. Hence, the Horizontal Gradient upward continued at 1, 3, 5, and 9 km, and Euler Deconvolution (using a structural index = 0), were applied in this study. As a result, contacts/faults were delineated from both methods. The solution depths of those contacts/faults were computed around 0.1–2.49 km from the Euler Deconvolution, with a good match with the contacts/faults obtained from the Horizontal Gradient upward continued at 1 km; the interpretation of the depth to the top and to the bottom of the Tchollire Banyo Shear Zone (TBSZ) was estimated between 0.1 and 0.49 km and > 4.5 km, respectively. Besides, the qualitative interpretation of the aeromagnetic data shows that the study area is characterized by contacts/faults trending in the NE–SW/ENE–WSW, E–W, and NW/SE–WNW–ESE directions which are consistent with the main structural directions observed in the field. Hence, the new structural framework was established from the aeromagnetic data processing results constrained with field data of Tchollire locality and environs; the structural deformation phases are defined by WNW–ESE to NW–SE foliation/schistosity linked to deformation phase D1, NE–SW/ENE–WSW regional foliation (D2), and E–W shear zones/contacts (D3). Furthermore, a proximal match was observed between both aeromagnetic lineaments and gold mining locations, suggesting a structural control of hydrothermal fluids linked to the gold mineralizations. Thus, the results of this study (lineaments and their depths) could serve as an important tool for prospective mining studies in Northern Cameroon. [ABSTRACT FROM AUTHOR]

The distinctive character of the Chinese camp on the goldfields is one of the missing elements in the history of the gold era of Victoria in the second half of the nineteenth century. This article uses imagery derived from a high-precision LiDAR survey to recover evidence of the structures and the community of a remote Chinese camp. It describes an interactive approach to generating, visualising, and analyzing LiDAR derived terrain models designed to cater for misclassification of LiDAR ground points and variable relationships between natural topographic variation and variations attributable to unrecorded cultural features. The results of spatial analysis and visualisations shed light on the physical character of the camp, the character of the community inhabiting it, and its eventual fate. [ABSTRACT FROM AUTHOR]

In this paper we test a long-held assumption regarding Otago, New Zealand, goldfields life and death- that scurvy was a ubiquitous and persistent cause of misery and death among the goldminers. We will also explore a parallel argument that the Chinese market gardeners played a large role in stamping out the disease in the goldfields. Through the interrogation of various archival medical primary sources, we show that scurvy was indeed a terrible scourge in the Otago goldfields, but only during the initial rushes into new regions. We also argue that while Chinese market gardeners undoubtedly contributed to a more nutritious and varied diet for European miners and settlers, scurvy had already markedly reduced in frequency by the time of their arrival in the gold fields. Patient-oriented accounts of scurvy in the gold demonstrate the clinical and functional cost of scurvy in during the initial gold rushes of Otago. Furthermore, individual stories of previously anonymous patients found locked in these archival sources demonstrate the importance of re-humanising the past to understand the biological and social context of these frontier times. [ABSTRACT FROM AUTHOR]

This study aims to identify critical points by calculating the water footprint (WF) of a mine and assessing the environmental impact of this water usage. Utilising the Water Footprint Assessment (WFA) methodology for critical points and the Life Cycle Assessment (LCA) methodology for environmental impact, results reveal that, among the identified hotspots, the highest blue water footprint is associated with the lost return flow, measuring 260.61 m3/kg Au. Regarding the grey water footprint, arsenic exhibits the highest value, measuring 1.777 m3/kg Au. Among the five impact categories, climate change human health emerges as the most environmentally affected category. [ABSTRACT FROM AUTHOR]

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Purpose: In addition to its considerable economic benefits, mining generally has a significant environmental impact on the ecosystem and human health, despite the efforts made. Mali, the 13th gold producer in the world and 3rd in Africa, deserves very special attention. This paper aims to identify and assess the potential environmental impacts and environmental hotspots of gold mining in Mali, using a life cycle assessment (LCA) approach. Methods: An industrial gold mine located west of Bamako in the Kéniéba circle in Mali exploiting two main underground deposits was considered in this paper. SimaPro software (v.9.0.0) is used for LCA by applying the ReCiPe 2016 Midpoint/Endpoint (H) V1.08 method to quantify the impacts generated. In addition, a sensitivity analysis of the scenarios proposed by Bjorklund is carried out to improve the reliability of the results obtained. Results and discussion: The results show that the main category of impact of gold mining that contributes most to the total environmental impact is human carcinogenic toxicity due to the production of electricity, the use of diesel, heavy fuel oil, hydrogen peroxide, sodium cyanide, aluminium chloride, and on-site emissions. In addition, the impacts of fossil resource depletion, terrestrial ecotoxicity, ozone formation in terrestrial ecosystems, mineral resource depletion, ozone formation in human health, terrestrial acidification, global warming, marine ecotoxicity, fine particle formation, and freshwater ecotoxicity also contribute considerably. Water consumption is identified as a positive impact of gold mining. Conclusion: Following the identification of environmental hotspots by this paper, further research is strongly recommended into the efficient production and rational consumption of energy and the choice of less energy-intensive, green technologies to promote more environmentally efficient gold mining. [ABSTRACT FROM AUTHOR]

Acid mine drainage occurs when sulfide minerals in mining activities come into contact with water and air, generating water with a low pH, high levels of sulfate, and metals. Treating acid mine drainage is a major challenge in gold mining operations worldwide and can be very costly. This study aims to screen and experimentally test potential local wetland plants for acid mine drainage treatment. Selected wetland plants were tested in a 12-liter plastic container, simulating a wetland treatment. The results of this study revealed that four out of six plants survived under acid mine drainage conditions. These plants included Cyperus imbricatus, Pennisetum purpureum, Typha latifolia, and Phragmites mauritianus,which all showed survival over the 63 days of experimental monitoring. The remaining two plants, Ipomea aquatica and water lotus (Nymphaeaceae), died within seven days of the experiment. The surviving plants were able to increase the pH from 3.2 to 7.1 and lower the levels of sulfate and metals in the acid mine drainage water. Furthermore, these four plants were able to improve the water quality by more than 94%, reducing heavy metal levels significantly (Mn from 53 to 1 mg/L, Ni from 2.4 to 0.3 mg/L, and Fe from 2.3 to 0.03 mg/L). This study suggests that selected local wetland plants have the potential to be a sustainable technology for treating acid mine drainage water. [ABSTRACT FROM AUTHOR]

Tailings pond is considered as the main source of heavy metal pollution in gold mining areas. These heavy metals are directly released into fresh water without proper treatment. Phytoremediation process with the selected terrestrial plants may be an alternative solution for the mine wastewater treatment. In the current study, an experimental investigation found that Rumex nepalensis Spreng. has found a good accumulator of multi-metals in 15 days of experimental period. The results revealed that the removal efficiencies for Zn, Cu, Ni and Pb were 100%, 92%, 87%, and 67%, respectively. These indicate the plant showed its maximum accumulation of multi-metals. However, Pb reached saturation at the end of the 10th day, which makes its removal efficiency only in the first 10 days of the experimental period. The experiment revealed Pb and Ni which were above WHO standard for drinking water in the mine wastewater were made to permissible limit for these metals after the treatment. [ABSTRACT FROM AUTHOR]

Purpose: With the recent increasing relevance of sustainability, multinational enterprises are faced with divergent stakeholder demands and persistently shifting priorities. This study aims to examine stakeholders' perceptions of the sustainability performance of a gold mining subsidiary in Ghana. Design/methodology/approach: Using a purposive sampling technique, the authors interviewed managers and employees of the case enterprise, officials of regulatory institutions and host community members on their perceptions of the case enterprise's sustainability performance. The authors triangulated the opinions expressed by these stakeholders with data from annual reports. The data were analysed through the lens of stakeholder theory. Findings: The authors found that while members of the host community and the regulatory institutions were keenly interested in the case enterprise's social and environmental activities, they perceived their performance as unimpressive, considering the economic benefits derived from the mining operations. On the contrary, the managers and employees of the case enterprise were satisfied with their environmental compliance and social intervention programmes, even though the company's economic position had declined. The authors submit that the variations in the sustainability performance perceptions among the stakeholders are due to the lack of a deeper understanding of the other stakeholders' expectations. Practical implications: To equitably satisfy diverse stakeholder expectations, the study highlights the role of stakeholder collaborations in understanding the expectations of more salient stakeholder groups such as community members and employees, as well as the lesser salient groups such as academics. It also demonstrates the fluidity of sustainability and its benefits in designing a consensual sustainable management strategy. This implies that managers of the case mining enterprise make the necessary efforts to meet the diverse stakeholder needs while attaining their primary objective of creating wealth for shareholders. Originality/value: Compared to advanced economies, studies on sustainability performance in emerging economies are limited. Nonetheless, these limited studies leave out stakeholder perceptions, focusing more on quantitative performance indicators. Using thematic and content analyses, the authors investigate stakeholder perceptions on the sustainability performance of a case mining subsidiary operating in Ghana. The study focused on Ghana because it is ranked with South Africa as the top two producers of gold in Africa. Nonetheless, unlike South Africa, Ghana faces more sustainability challenges from the mining sector due to weak institutions in enforcing sustainability standards. [ABSTRACT FROM AUTHOR]

Artisanal small-scale gold mining (ASGM) using mercury affects community agreements for the conservation of forests (CoS) and lakes (CoH), which have a high level of biodiversity in the Peasant Reserve Zone of the Cimitarra River Valley (ZRC-VRC) in Colombia. In this research, a multi-criteria approach (MCA) was applied to analyze the impact of ASGM. This analysis is based on the community environmental agreements to preserve CoS and CoH areas, the ecological importance of these areas, as well as the results of mercury dispersion in the Cimitarra river basin, with concentrations found 40 km downstream of the mining area of 0.09 µgTHg L−1 in the Cimitarra river, 0.07 µgTHg L−1 in the CoH, and 0.01 mgTHg kg−1 in the tissues of macrophytes, as well as the increase in deforestation since 2020 in the CoS, due to a 1.8% (990 ha) loss of forest cover, with 693 ha of the forest cover loss coinciding with areas related to the opening of new mines. The MCA showed that the main impact is found within the criterion Social and armed conflict, followed by Deforestation. This research offers recommendations to reduce impact scores, such as the implementation of a sustainable development plan (PDS) of the ZRC-VRC, and it highlights the urgent need to safeguard the community conservation areas. [ABSTRACT FROM AUTHOR]

This article explores operational challenges in mining, with a focus on energy management amid depleting ore grades and rising costs. The urgent need for innovative energy management systems and strategies is highlighted by analyzing the unexplored landscape of mine energy budgeting and forecasting and identifying gaps in current practices. Drawing from the literature, this paper offers new insights into energy budgeting and the evaluation of energy efficiency initiatives by integrating traditional and advanced measurement and verification (M&V) techniques. M&V practices are crucial for energy management, particularly in deep-level mines, with a focus on practical knowledge and advanced methodologies. Key findings from this study show that integrating advanced M&V techniques with unplanned events is crucial to improve the financial management of mines. By leveraging these key findings, this article proposes a roadmap of the next seven milestones needed in advanced M&V research to aid effective energy management in a mining environment. If executed successfully, a practical method for applying advanced M&V processes to deep-level mining operations can be constructed. Such a generic method will enhance mining companies' energy efficiency initiatives and improve financial management practices on a global scale. [ABSTRACT FROM AUTHOR]

In recent decades, artisanal and small-scale gold mining (ASGM) has spurred population and economic growth in the small rural communities in which it is located, along with causing contamination of the soil, air, and water with grave effects on human health due to the uncontrolled use of mercury for gold processing activities. This study analyzes the levels of mercury in Secocha, an ASGM community in Arequipa, Peru. A total of 44 soil samples were taken from two ASGM commercial-extractive zones (n = 18) and non-processing urban zones (n = 26). Soil mercury analysis with atomic absorption spectrometry revealed average mercury levels of 86.11 mg/kg in commercial-extractive zone I, where ore processing has occurred for about 17 years, and mercury levels of 43.81 mg/kg in commercial-extractive zone II, where processing has occurred for about 7 years. In the urban zone, the average mercury level was 9.53 mg/kg. The average mercury concentrations for each zone exceed the relevant environmental quality standards established by the Peruvian Ministry of the Environment. In addition, urine samples were obtained from 15 miners and 15 people from the general urban population (non-miners). The average mercury level in the urine of miners was 7.04 µg/L, and in the urine of non-miners it was 0.49 µg/L. In both cases, the mercury urine level did not exceed the limits established by WHO and the Peruvian Ministry of Health, though miners' elevated levels do raise concerns. [ABSTRACT FROM AUTHOR]

Excessive emissions of heavy metals not only cause environmental pollution but also pose a direct threat to human health. Therefore, rapid and accurate detection of heavy metals in the environment is of great significance. Herein, we propose a method based on laser-induced breakdown spectroscopy (LIBS) combined with filter paper modified with bovine serum albumin-protected gold nanoclusters (LIBS-FP-AuNCs) for the rapid and sensitive detection of Cr3+ and Mn2+. The filter paper modified with AuNCs was used to selectively enrich Cr3+ and Mn2+. Combined with the multi-element detection capability of LIBS, this method achieved the simultaneous rapid detection of Cr3+ and Mn2+. Both elements showed linear ranges for concentrations of 10–1000 μg L−1, with limits of detection of 7.5 and 9.0 μg L−1 for Cr3+ and Mn2+, respectively. This method was successfully applied to the determination of Cr3+ and Mn2+ in real water samples, with satisfactory recoveries ranging from 94.6% to 105.1%. This method has potential application in the analysis of heavy metal pollution. [ABSTRACT FROM AUTHOR]

In Ecuador, illegal gold mining has led to significant environmental impacts, with the release of harmful elements such as mercury (Hg) into the environment. Mercury, due to its physical–chemical characteristics and the transport elements involved between different environmental matrices, can easily percolate through the soil and reach groundwater. The purpose of this study was to evaluate the mercury concentration levels in the Andean region in order to perform a human health risk assessment. For this purpose, 175 water samples were analyzed, of which 9.71% exceeded the maximum permissible limit (MPL) established for drinking water in accordance with Ecuadorian regulations. The risk analysis was conducted by applying two approaches: deterministic and probabilistic. The deterministic approach involves a specific analysis based on the calculation of the risk quotient (HQ) and risk index (HI) for both receptors (adults and children) and scenarios (residential and recreational) considered; the probabilistic approach is based on the use of stochastic simulation techniques. The results obtained from the two approaches show a discrepancy, with the deterministic analysis providing more conservative results; however, they coincide in showing higher risk for the child population; decision-makers could use these results to identify areas to be monitored and plan more detailed investigation plans. [ABSTRACT FROM AUTHOR]

The gold rush in the Faleme catchment between Senegal and Mali involves artisanal miners from the sub-region, European and American multinationals, and medium-sized Chinese companies. These miners, with their disproportionate financial and material resources, practise three types of gold mining (artisanal, industrial and semi-industrial) involving the Faleme River. The mining techniques used by these operators are now a major source of damage to the river. This damage is mainly water pollution, the destruction of riverbanks, and the disappearance of aquatic fauna and agro-pastoral activities. The level of degradation is a source of speculation. Attempts are made to emphasize that artisanal exploitation is the main activity degrading the river. This article deconstructs these arguments with evidence showing that, in addition to artisanal gold mining, industrial and semi-mechanical mining activities are major contributors to the degradation of this river.

Background: Artisanal gold mining can help reduce poverty while creating job possibilities for many low-income and unskilled workers. However, it is an activity with several detrimental societal consequences. Miners are exposed to chemical toxins that have long-term health consequences. Objectives: This study examined soil degradation, pollution, and environmental hazards from artisanal gold mining in Ibodi-Ijesa, Osun State, Nigeria. The aim is to assess the levels of Cu, Co, Cd, Pb, As, and Ni in the study area as potential indicators of environmental concerns. Methods: Soil samples were systematically collected from 66 distinct locations surrounding the gold mining site, at depths ranging from 0 to 15 cm, within distances of 0 to 500 m, and at intervals of 100 m. These samples underwent standard laboratory procedures for heavy metal analysis using Atomic Absorption Spectroscopy (AAS).Results: The findings showed that copper (Cu), cobalt (Co), lead (Pb), and nickel (Ni) concentrations ranged from 80.17 to 100.11 mg.kg−1, 42.11 to 50.07 mg.kg−1, 30.93 to 54.00 mg.kg−1, and 35.30 to 44.20 mg.kg−1, respectively. Nickel (Ni), cadmium (Cd), and arsenic (As) were all below the detection limit. Although all analysed heavy metal concentrations were lower than the control samples, they outperformed the control values. The contamination index showed no distinct distribution pattern, but all values surpassed those of the control samples. Furthermore, the Health Risk Index was greater than one, indicating possible health hazards for inhabitants. Conclusion: The study indicated that artisanal gold mining operations in Ibodi-Ijesa substantially influenced soil quality, raising heavy metal concentrations and posing health hazards to adjacent populations.

Traditional gold mining (TGM) is among the off-farm income sources of smallholder communities in the highlands of Ethiopia. However, information on their impact on land degradation, taking soil loss as a key indicator, was scant. Hence, this study aimed at i) analyzing local communities’ attitudes toward TGM practice, ii) TGM impact on soil loss, and iii) possible restoration measures for the degraded gold-mined landscapes. For the evaluation of community perceptions, 96 beneficiaries were selected from three gold mining sites following stratified random sampling techniques. Soil loss measurement was done through measurement of i) the mass of soil excavated and transported to the river (TR) from 96 individuals and ii) soil volume excavated in 45 excavated soil pits (EP). Descriptive statistics and one-way ANOVA were used to analyze soil loss data, while community perception was analyzed qualitatively. The survey results indicated that the average soil loss from TR and EP were 6,075.97±8.9 t ha-1 yr-1 and 32,549.99±753.68 t ha-1, respectively. The magnitude of soil loss also showed a significant (p

Abstract The assessment of natural radionuclides in soil samples from artisanal gold mine sites in Iperindo, Nigeria was conducted using different analysis methods. Soil samples collected across three locations and within a control area were analyzed using well-calibrated gamma spectroscopy fitted with a sodium iodide detector. The average activity concentrations (ranges) of 238U, 232Th, and 40 K were found to be 61.55 ± 13.97 (33.40–87.00) Bqkg−1, 72.65 ± 16.83 (41.90–105.10) Bqkg−1, and 1134.99 ± 142.24 (720.50–1722.10) Bqkg−1, respectively for the mining areas and 15.26 ± 6.96 (10.90–20.10) Bqkg−1, 21.46 ± 9.35 (17.40–25.30) Bqkg−1, and 381.04 ± 51.27 (280.30–511.70) Bqkg−1, respectively for the control locations. The average activity concentrations of the radionuclides assessed were above the worldwide permissible limits for the Iperindo mining areas and below the worldwide average for the control areas. The investigation also assessed various radiological parameters, encompassing the radium equivalent, dose rate, annual effective dose rate, internal and external hazard indices, alpha and gamma indices, annual gonadal equivalent, and excess lifetime cancer risk. The recorded values for mine locations were 252.83 Bqkg−1, 119.98 nGyh−1, 0.15 mSvy−1, 0.85 Bqkg−1, 0.68 Bqkg−1, 0.31 Bqkg−1, 1.89 Bqkg−1, 850.23 μSvy−1, and 0.52 $$\times$$ × 10−3, respectively. Except for the radium equivalent, external and internal hazard risks, and the alpha index, which were notably below the recommended threshold, all the other radiological parameters exceeded the globally advised limits. All the radiological parameters from the control areas were below the worldwide average values.

"Where Treasures Shine: Lionel Gee, A Forgotten South Australian Mining Identity" is a comprehensive biography by Judy Fander that sheds light on the overlooked contributions of Lionel Gee to the mining industry in South Australia and the Northern Territory in the late 19th and early 20th centuries. Gee's career spanned over 50 years, during which he rose from a cadet surveyor to a goldfields warden. The biography highlights Gee's engaging personality, diverse talents, and community involvement. It also provides vivid descriptions of the harsh conditions on the goldfields and Gee's role in settling disputes and advocating for miners' needs. The book is a valuable resource for those interested in mining history and South Australian history in general. [Extracted from the article]

The article discusses the book "Before Gold: The Northampton Mineral District 1846-1880" by J.M.R. Cameron, which explores the forgotten early history of the mining industry in Western Australia. The book highlights the efforts of early colonists to develop the mining industry, particularly in copper and lead mining, as a means of economic salvation. However, the industry faced numerous challenges including lack of capital, underdeveloped infrastructure, natural disasters, and a shortage of labor and expertise. Despite some moments of hope, the overall development of the mining industry in the Northampton area was slow and ultimately unsuccessful. The book provides valuable insights into this lesser-known period of Western Australian mining history. [Extracted from the article]

Plasmonic gold nanoparticles (AuNPs) can convert laser irradiation into thermal energy for a variety of applications. Although heat transfer through the AuNP–water interface is considered an essential part of the plasmonic heating process, there is a lack of mechanistic understanding of how interface curvature and the heating itself impact interfacial heat transfer. Here, we report atomistic molecular dynamics simulations that investigate heat transfer through nanoscale gold–water interfaces. We simulated four nanoscale gold structures under various applied heat flux values to evaluate how gold–water interface curvature and temperature affect the interfacial heat transfer. We also considered a case in which we artificially reduced wetting at the gold surfaces by tuning the gold–water interactions to determine if such a perturbation alters the curvature and temperature dependence of the gold–water interfacial heat transfer. We first confirmed that interfacial heat transfer is particularly important for small particles (diameter ≤ 10 nm). We found that the thermal interface conductance increases linearly with interface curvature regardless of the gold wettability, while it increases nonlinearly with the applied heat flux under normal wetting and remains constant under reduced wetting. Our analysis suggests the curvature dependence of the interface conductance coincides with changes in interfacial water adsorption, while the temperature dependence may arise from temperature-induced shifts in the distribution of water vibrational states. Our study advances the current understanding of interface thermal conductance for a broad range of applications. [ABSTRACT FROM AUTHOR]

Interfacial thermal conductance (ITC) quantifies heat transport across material–fluid interfaces. It is a property of crucial importance to study heat transfer processes at both macro- and nanoscales. Therefore, it is essential to accurately model the specific interactions between solids and liquids. Here, we investigate the thermal conductance of gold–water interfaces using polarizable and non-polarizable models. Both models have been fitted to reproduce the interfacial tension of the gold–water interface, but they predict significantly different ITCs. We demonstrate that the treatment of polarization using Drude-like models, widely employed in molecular simulations, leads to a coupling of the solid and liquid vibrational modes that give rise to a significant overestimation of the ITCs. We analyze the dependence of the vibrational coupling with the mass of the Drude particle and propose a solution to the artificial enhancement of the ITC, preserving at the same time the polarization response of the solid. Based on our calculations, we estimate ITCs of 200 MW/(m2 K) for the water–gold interface. This magnitude is comparable to that reported recently for gold–water interfaces [279 ± 16 MW/(m2 K)] using atomic fluctuating charges to account for the polarization contribution. [ABSTRACT FROM AUTHOR]

• The utilization characteristics of gold tailings were reviewed. • The recovery of valuable components from gold tailings was summarized. • The application of gold tailings in the field of materials was adumbrated. • A new process combining magnetic separation and cemented filling was proposed. Gold tailings are characterized by low-grade, complex composition, fine embedded particle size, environmental pollution, and large land occupation. This paper describes the mineralogical properties of gold tailings, including chemical composition, phase composition, particle size distribution, and microstructure; summarizes the recycling and utilization of components such as mica, feldspar, and valuable metals in gold tailings; reviews harmless treatment measures for harmful elements in gold tailings; and adumbrated the research progress of gold tailings in the application fields of building materials, ceramics, and glass materials. Based on these discussions, a new technology roadmap that combines multistage magnetic separation and cemented filling is proposed for the clean utilization of all components of gold tailings. [ABSTRACT FROM AUTHOR]

We studied the morphostructural features and chemical composition of micron and submicron particles of native gold from brown coals and overcoal sediments of the Yerkovetsky deposit (Zeya-Bureya sedimentary basin, Far East Russia). The samples of coal and host rocks in the form of thin sections, as well as coal particles and grains of native gold obtained during the process of dispersion and the fractionation of loose and crushed samples divided according to size and density, were analyzed using scanning electron microscopy in combination with X-ray microanalysis, involving various visualization modes. It was revealed that native gold is syngenetic with the mineralization of brown coals, and microphases dispersed in the minerals of overcoal loose and sandy-clay sediments were the source of native gold. In coal, gold is accumulated at the stages of formation (alluvial and eolian, including terrigenous and ionogenic subtypes) and the diagenesis of coal deposits (ground-infiltration subtype). A significant part of the mineralization process of coals and the formation of microparticles of native gold was contributed to by the descending water infiltration of polycomponent colloid solutions. During the dehydration of hydroxysiliconized iron-based hydrogels, mineral phases have an unstable composition and floccular structure and contain submicron gold particles. The coatings of all gold microparticles have identical origin and composition. Coal beds that border host rocks are an open system with a constant inflow of the substance, which leads to the gradual formation of polycomponent aggregated particles in micro cavities. Part of the gold in coals occurs as sulfur-bearing complexes dissolved in pore water. The key factor in the migration and deposition of gold in coals is the inorganic substances involved in the processes of coal mineralization. Organic substances play a more passive role and have medium-forming, fractionating (colloid, molecular, and ionic sieves), and accumulation functions. [ABSTRACT FROM AUTHOR]

With the increasing integration of renewable energy sources into distribution and transmission networks, the efficiency of cascade H-bridge multilevel inverters (MLIs) in power control applications has become increasingly significant for sustainable electricity generation. Traditionally, obtaining optimal switching angles of MLIs to minimize total harmonic distortion (THD) requires solving the selective harmonic elimination equations. To this end, this research aims to use two recently developed intelligent optimization algorithms, dandelion optimizer and gold rush optimizer, to solve this problem. To evaluate the effectiveness of the proposed algorithms, an eleven-level cascaded H-bridge MLI (CHB-MLI) was considered in the study. Simulation results for different modulation indices were obtained, and the accuracy and solution quality were compared with genetic algorithm and particle swarm optimization algorithms. MATLAB/Simulink-based models were used to verify numerical computations, ensuring the reliability of the findings. This research contributes to the field by providing insights into obtaining optimal switching angles and minimizing THD in MLIs by applying intelligent optimization algorithms. [ABSTRACT FROM AUTHOR]

Context and background This study aims to study, through a socio-systemic approach, the cohabitation between agricultural land and gold panning, if not the occupation of agricultural land by gold panning. To this end, we decided to focus on the case of the rural commune of Bancoumana, Kati circle, Koulikoro region, an agricultural area par excellence, but faced with the invasion of gold panning. This commune, located on the outskirts of Bamako, is experiencing a desire for its land suitable for agriculture (cereals, citrus fruits, fruits and vegetables). Through this study, we ask the question of how agriculture coexists with gold panning? What are the effects and impacts of one on the other? What measures or arrangements have been taken by the politicaladministrative authorities to protect agricultural land from gold panning? How are these measures perceived by the populations, particularly farmers? Goal and Objectives: Study the cohabitation between agricultural land and gold panning. This involves studying the effects, if not the impacts, of one on the other. Methodology: To carry out the study, our approach is based on empirical research methods. First, we carry out a documentary analysis in order to pose the problem of the study. Secondly, we carry out field surveys using individual and collective interview guides with the stakeholders concerned, in particular farmers, gold miners, local and regional authorities, and managers of farmers' defense NGOs. For the analysis of the data collected in the field, we favored the analysis of thematic content according to our centers of interest. The data collected in the local "Bambara" language were transcribed into French for this purpose. Results: The results of the study reveal that the idleness of rural and urban young people explains their rush to gold panning areas. It also shows that gold panning seriously impacts agriculture, particularly family farming. The impacts are of several orders. Encroachment or invasion on agricultural areas, flight of agricultural labor, decline in agricultural productivity, decline in agricultural income and land conflicts between farmers and gold miners. [ABSTRACT FROM AUTHOR]

The article focuses on the environmental and cultural impact of the Gold Rush on Ballarat, highlighting the devastation caused to the landscape and the traditional way of life of the Wadawurrung people. Topics include the rapid transformation of the Yarrowee River system due to gold mining, the historical significance of the river to Indigenous custodians, and the innovative use of digital mapping technology to visualize and understand these environmental changes over time.

This article provides a historical overview of the Eidsvold goldfields in Queensland from the 1880s to the 1910s. It explains how the discovery of the Gympie goldfield in 1867 led to increased immigration and capital in Queensland. The Queensland government actively sought immigrants and British capital for the mining industry, showcasing a quartz-crushing mill and gold-bearing ore at an exhibition in London in 1886. Gold discoveries in Eidsvold in the 1880s resulted in the establishment of a goldfield and the development of mines like Mount Rose and Stockman Junction. The Eidsvold goldfields experienced a peak in production from 1888 to 1893, but by 1901, their decline had begun. The goldfields played a crucial role in sustaining Queensland's economy during an economic depression and drought in the late 19th and early 20th centuries. The article also provides information on the gold mining industry in Eidsvold, including differences in gold production compared to Charters Towers, working conditions and disputes faced by miners, political affiliations of the miners, challenges with sanitation and water supply, and the prevalence of typhoid fever in the goldfields. It concludes with details about the present-day population of Eidsvold and its mining history. [Extracted from the article]

Gold(I)‐thiolate complexes have served as primary building blocks for diverse Au nanostructure synthesis strategies. A delicate approach to characterize and control Au(I)‐thiolate motif formation and assembly on the surface is needed as it can potentially solve challenges associated with utilizing gold nanomaterials in many applications. Here, the controllable generation of flower‐shaped surface gold nanostructures (FSGNs) is demonstrated by manipulating the formation‐assembly process of Au(I)‐dodecanethiolate motifs within nanoscale surface droplets. The morphology and structure of the resulting Au nanostructures are governed by internal convection flows and interfacial energy, modulated by the nanodroplet composition and substrate wettability. The obtained FSGNs are proven to act as versatile scaffolds for the selective generation of Au spiky nanostars. These FSGNs can also be utilized to functionalize nanodroplet‐based reactors, boosting the fluorescent intensity of Nile red (NR) fluorophores and decomposing NR via catalytic reaction. Remarkably, with FSGN functionalized droplets smaller than a radius of 500 nm, the decomposition rate of NR can reach ≈0.01 s−1. These results highlight a miniaturized, controllable, and automated method for the in situ production of 3D gold nanostructures on substrates, offering prospects for fast surface nanostructure fabrication and efficient environmental pollutant treatment. [ABSTRACT FROM AUTHOR]

Artisanal small-scale gold mining (ASGM), an increasingly prevalent activity in South America, generates mercury-contaminated tailings that are often disposed of in the environment, leading to the introduction of mercury into ecosystems and the food web, where it bioaccumulates. Therefore, studying the geochemical processes involved in the desorption and dissolution of mercury in these tailings is essential for critical risk evaluations in the short and long term. For this purpose, sequential extraction procedures (SEPs) can be useful because they help to identify the phases to which Hg is associated, although they also have limitations such as a lack of selectivity and specificity. In this work, we propose a modified four-step SEP: exchangeable mercury (F1), oxidizable mercury (F2), mercury bound to Fe oxides (F3), and strongly bound mercury (F4). To test this adapted sequential extraction method, we evaluated the Hg contamination in mercury-contaminated tailings of the Amazon basin. The results revealed a total mercury concentration of 103 ± 16 mg·kg−1 in the tailings, with a significant portion in F1 (28% of the total), where Hg was bioavailable. The large Hg concentration in F3 (36%) suggested that Fe oxides likely contribute to mercury retention. Together, the SEP results emphasize the urgent need for improved surveillance of gold mining activities and responsible tailings management practices to mitigate environmental contamination and safeguard the health of the Amazon ecosystem. [ABSTRACT FROM AUTHOR]

Artisanal and small-scale gold mining (ASGM) plays a crucial role in global gold production. However, the adoption of poor mining practices or the use of mercury (Hg) in gold recovery processes has generated serious environmental contamination events. The focus of this study is assessing the concentration of Hg in surface waters within the coastal region of Ecuador. The results are used to conduct a human health risk assessment applying deterministic and probabilistic methods, specifically targeting groups vulnerable to exposure in affected mining environments. Between April and June 2022, 54 water samples were collected from rivers and streams adjacent to mining areas to determine Hg levels. In the health risk assessment, exposure routes through water ingestion and dermal contact were considered for both adults and children, following the model structures outlined by the U.S. Environmental Protection Agency. The results indicate elevated Hg concentrations in two of the five provinces studied, El Oro and Esmeraldas, where at least 88% and 75% of the samples, respectively, exceeded the maximum permissible limit (MPL) set by Ecuadorian regulations for the preservation of aquatic life. Furthermore, in El Oro province, 28% of the samples exceeded the MPL established for drinking water quality. The high concentrations of Hg could be related to illegal mining activity that uses Hg for gold recovery. Regarding the human health risk assessment, risk values above the safe exposure limit were estimated. Children were identified as the most vulnerable receptor. Therefore, there is an urgent need to establish effective regulations that guarantee the protection of river users in potentially contaminated areas. Finally, it is important to continue investigating the contamination caused by human practices in the coastal region. [ABSTRACT FROM AUTHOR]

Copyright of Cameroon Academy of Sciences Journal is the property of Cameroon Academy of Sciences 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 the practice of gold mining industry, hazardous waste known as tailings is produced during the ore extraction process. These tailings are typically stored in a dam structure called a Tailings Storage Facility (TSF). The planning and construction of a TSF are critical considerations, as the failure of a TSF can have substantial environmental impacts, pose risks to human safety, and result in industrial losses. Therefore, strict control is necessary in the development of TSFs to minimize the potential negative consequences. This research focuses on the transport of contaminants within a TSF, specifically examining the concentration of chloride contaminants and conducting particle movement analysis. The study utilizes modeling through the GeoStudio SEEP/W program to simulate groundwater flow profiles and the GeoStudio CTRAN/W program to understand contaminant movement over a 100-year period. GeoStudio modeling employs 10 materials: impermeable clay soil, filter sandy soil, transition gravel rock, three mine waste types (Fine, Rockfill, and Rockfill with fine), hard rock bedrock layer, in-situ soil representing the original layer, landslide with colluvial soil, and the tailings itself. Back analysis is employed to iterate model parameters and ensure modeling accuracy against field data, including comparisons with water quality test results and readings from vibrating wire piezometer (VWP) instrumentation. The contaminant transport is influenced by advection-dispersion processes and tends to concentrate within the TSF boundary toward the dam toe over a 100-year timeframe. The analysis emphasizes the influence of advection in contaminant transport and underscores the importance of particle position relative to the groundwater level, with Particle Tracking Analysis shows significant movement within the groundwater flow area. This research provides crucial insights into the dynamics of contaminant concentration, informing better decision-making in TSF planning and management. The findings underscore the imperative of strict control measures to minimize environmental impacts and human safety risks associated with TSFs, thereby advancing knowledge in gold mining waste management. [ABSTRACT FROM AUTHOR]

South Africa is a water scarce country with a semi-arid climate. The pollution of freshwater resources by the acid mine drainage (AMD), which is mostly acidic and hard, has exacerbated the problem. This research focuses on the treatment of AMD from the three goldfields (Eastern - EB, Central - CB and Western - WB basins) of the Witwatersrand basin, Gauteng, South Africa with the aim of recovering water (fit-for-purpose) and marketable mineral(s) for industrial use. In this preliminary study, the AMD water samples from these three basins were subjected to urea hydrolysis at varying urea concentrations (urea to total metal [U]/[M] ratios ranging from 3.3 to 10), constant reaction times (3 h) and temperature (80 °C). This resulted in the pH of the AMD water samples of the three basins (EB, CB and WB) being increased to an average of approximately 8.8, and the softening of water, with more than 98% removal of calcium. The sulphate removal ranged between 38 to 50%, while the method also displayed a positive impact in the reduction of magnesium (up to 34%) and the monovalent cations (sodium up to 33% and potassium up to 44%) from the polluted AMD water samples. In addition, calcium carbonate (aragonite polymorph), a mineral with vast industrial applications, was recovered in the process. The significance of the findings is that, firstly an environmentally benign method has been demonstrated to effectively soften and remove the AMD pollutants. Secondly, the AMD pollutants were converted to a valuable industrial product without generating any waste in the process. [ABSTRACT FROM AUTHOR]

Copyright of Central Asian Economic Review is the property of Narxoz University 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.)