Ore Minerals Research Articles

Pneumatolytic type of ore mineralization within the elbrus volcanic center (North caucasus, Russia)

Pneumatolytic type of ore mineralization within the elbrus volcanic center (North caucasus, Russia)

A Quantitative Particle-Based Approach for the Geometallurgical Assessment of Tailings Deposits

Tailings generated during ore processing may host significant residual contents of valuable commodities, including critical metals. The particle properties of the tailings, such as mineralogy, particle size, and the surface liberation of ore minerals, strongly control processing behaviour. This study explores a novel combination of methods for incorporating particle data, derived from automated mineralogy, into geometallurgical models of tailings deposits to better understand their reprocessing potential and the economic feasibility of re-mining. This was achieved through binning of different particle types, geostatistical modelling of particle bin frequencies, and bootstrap resampling to reconstruct particle populations. The spatial distributions of processing-relevant particle properties throughout the tailings deposit were predicted with corresponding uncertainties. There are clear systematic trends in the spatial distributions of different particle types, resulting from the sedimentary-style deposition of the tailings. For instance, the tailings nearer the dam walls comprise coarser, silicate-rich particles, while fine-grained and well-liberated sulphide mineral particles are more abundant in the centre of the tailings deposit. As a result, robust models could be developed for the spatial distributions of particle size and mineralogy, which strongly control the sorting of particles during deposition, and other related properties, such as sulphide mineral grain sizes. Finally, a bulk sulphide flotation process was simulated and acid mine drainage potential estimated using the interpolated particle data. Around 58% of the sulphide minerals present could be recoverable by flotation, with the recoverable sulphide portion decreasing towards the centre of the TSF due to the fine-grained nature of the sulphide minerals. The acid mine drainage potential of the tailings is estimated to be moderate to high, indicating that the carbonate minerals present are not sufficient to neutralise the high acid-generating potential of the sulphide minerals. Overall, this study demonstrates how particle-based geometallurgical models can be developed and utilised for practical applications, with the aim of improving the accuracy of resource and reserve estimations of tailings deposits and the sustainable and responsible management of anthropogenic resources. The methodology proposed here can be easily transferred to other tailings deposits.

Raman spectroscopy study of structural changes in pyrophyllite ore minerals induced by mechanochemical milling

Mechanical milling of the pyrophyllite ore leads to an increase in material chemical reactivity. This is a consequence of structural changes occurring during the milling process and depends on the milling time. This work aims to investigate structural changes caused by the mechanical milling of pyrophyllite ore using Raman spectroscopy for possible application in wastewater remediation. It was shown that the quartz bands at 122 cm−1 or 459 cm−1 could be references for tracking the phyllosilicate and calcite structural changes. The intensity ratio of quartz and phyllosilicate/calcite bands increases considerably with increasing milling time. Also, the Full Width at Half Maximum (FWHM) evolution of the 257 cm−1, 701 cm−1, and 1078 cm−1 bands has a similar trend as the mentioned intensity ratio. Based on the obtained results, it can be concluded that Raman spectroscopy is a suitable tool for structural changes monitoring in this natural clay caused by mechanical milling.

Ore Elements and Minerals in The Elements of Alaid Volcano (Kuril Island Arc)

Sublimates tested in 2013–2020 were studied. in the near-crater zone and on the slopes of the Alaid volcano, located in the Kuril Island arc. It has been established that in the near-crater zone there are native metals confined to zones of acid leaching, within which the original lavas and tuffs have been transformed into opal-like formations or rocks sharply enriched in ferric hydroxides. In these zones, the presence of native gold, palladium, silver, chromium, copper, zinc and alloys of gold and palladium, copper and zinc, copper and tungsten has been established. On the slopes of the Alaid volcano, the range of minerals in sublimates is wider, while the temperature of their formation is lower. Of the ore minerals, copper-containing ones predominate, and sublimates with vanadium-containing minerals belonging to hydrous oxides and vanadate-silicates are established. Two genetic types of slope sublimates have been identified: 1) minerals crystallizing from hydrothermal or steam-hydrothermal solutions near the outcrops of near-surface fumaroles and 2) copper and ferruginous colomorphic formations formed as a result of sedimentation from colloidal solutions in the shallow waters of drying up reservoirs, including small and large puddles.

Experimental studies of the generating capabilities of mine hoists in industrial conditions

The article is devoted to a topical subject of distributed generation of electrical energy. The cage and skip mine hoists of the iron ore mining enterprise were considered as generators of electrical energy. The purpose of the study is to compare theoretical and experimental data on electricity generation by mine hoisting units of the Sukha Balka PJSK (Kryvyi Rih, Ukraine). The research methods are theoretical ones – on the transformation of the potential energy of a solid body into electrical energy during its movement through a mine shaft, and experimental ones – involving instrumental measurements of the consumption and generation of electrical energy by cage and skip hoists units during industrial operation. Research schedule: collection and processing of information on the operation of the cage and skip hoists of the mine named after Frunze and similar indicators of the cage and skip hoists units of the Yuvileyna mine for the period from September 1 to December 31, 2021. The novelty of the research lies in the instrumental measurement of the electrical parameters of mine hoists in real Ukrainian operating conditions. The most significant results: it was found that the volumes of electricity generation by mine cage hoists significantly exceed the results of skip hoists. The actual indicators of electricity generation by cage hoists units are much lower than the results of theoretical estimates. There is an imbalance between the generation and consumption of energy resources – 9% for the cage elevation of the mine Frunze; about 2% for the cage hoist of the Yuvileyna mine; less than 1% on skip units. It was found that there is a statistically significant correlative relationship between the generation and consumption of electricity by the cage hoist of the mine named after Frunze and no statistically significant relationship between the generation and consumption of electricity by the cage hoist unit of the Yuvileyna mine. The electricity obtained from the daily operation of two cage and two skip units of the Sukha Balka PJSC (approximately 400 kWh) is enough to power 58 average Ukrainian households.

Sustainable open pit mining through GHG-conscious short-term production scheduling

ABSTRACT The mining industry is a notable contributor to global greenhouse gas (GHG) emissions, posing challenges to achieving the Paris Agreement’s goal of capping emissions at 30 Gt CO2-equivalent annually by 2030. This paper introduces a novel Mixed Integer Linear Programming (MILP) model tailored for short-term open-pit mine planning that integrates environmental considerations, particularly GHG emissions, alongside economic objectives. The model handles complex operational challenges including block sequencing, multiple transport destinations, and stockpile management. Additionally, it provides the opportunity to examine the adoption of In-Pit Crushing and Conveying (IPCC) systems as the main transport method, an innovative approach aimed at reducing emissions from haulage – which accounts for over 35% of GHG emissions in open-pit mining. Applied to a case study in an iron ore mine, the model not only considers the environmental benefits of IPCC systems compared to traditional truck and shovel (TS) operations but also highlights significant reductions in haulage costs and carbon tax liabilities. The findings demonstrate that fixed IPCC (FIPCC) systems, in particular, offer substantial decreases in GHG emissions, presenting a compelling case for their broader adoption in the industry.

Addressing Environmental, Economic and Social Impact Mining Companies on Taliabu Island, North Maluku

The fundamental characteristic of the iron ore mining industry is clearing land and changing the natural landscape so that it has the potential to have an impact on the environment, social and economic aspects of society. This research was conducted to determine the environmental, social and economic impacts on the people of Taliabu Island Village. This research uses a qualitative method with a case study method. The conclusion of this research is that the environmental impact caused by mining in the Taliabu Island Village area can still be overcome by the company by replanting trees in places where mining has been completed and the company even provides signs along roads and dangerous areas so that the community is protected from these environmental impacts. . The company can also overcome the social impacts that arise by providing equal career development opportunities for local employees and migrant employees so that social jealousy does not occur and economic welfare increases for the people of Taliabu Island Village. The community's economy has improved with the opportunity to work as company employees and the emergence of many food stalls, daily necessities stalls and even entertainment venues where previously the community had a source of income from clove and head plantations. The company also establishes a family relationship between the village head and all members of the community so that the impact, no matter how small, can still be overcome because all levels of society have a sense of ownership of the company and the benefits of the company are greatly felt.

Natural Water Sources and Small-Scale Non-Artisanal Andesite Mining: Scenario Analysis of Post-Mining Land Interventions Using System Dynamics

Small-scale open-pit, non-artisanal mining of low-value ores is an understudied practice despite its widespread occurrence and potential impact on freshwater resources due to mining-induced land-use/cover changes (LUCCs). This research investigates the long-term impacts of andesite mining in Pasuruan, Indonesia, on the Umbulan Spring’s water discharge within its watershed. System Dynamics (SD) modeling captures the systemic and systematic impact of mining-induced LUCCs on discharge volumes and groundwater recharge. Agricultural and reservoir-based land reclamation scenarios then reveal post-mining temporal dynamics. The no-mining scenario sees the spring’s discharge consistently decrease until an inflection point in 2032. With mining expansion, reductions accelerate by ~1.44 million tons over two decades, or 65.31 thousand tons annually. LUCCs also decrease groundwater recharge by ~2.48 million tons via increased surface runoff. Proposed post-mining land interventions over reclaimed mining areas influence water volumes differently. Reservoirs on reclaimed land lead to ~822.14 million extra tons of discharge, 2.75 times higher than the agricultural scenario. Moreover, reservoirs can restore original recharge levels by 2039, while agriculture only reduces the mining impact by 28.64% on average. These findings reveal that small-scale non-artisanal andesite mining can disrupt regional hydrology despite modest operating scales. Thus, evidence-based guidelines are needed for permitting such mines based on environmental risk and site water budgets. Policy options include discharge or aquifer recharge caps tailored to small-scale andesite mines. The varied outputs of rehabilitation scenarios also highlight evaluating combined land and water management interventions. With agriculture alone proving insufficient, optimized mixes of revegetation and water harvesting require further exploration.

Fluid evolution of the Nulasai Cu deposit, Xinjiang, NW China: Evidence from fluid inclusions and O-H-C isotopes

The Nulasai deposit is the earliest Cu mine in Xinjiang, NW China, and has been mined and smelted since the warring state period. Another striking characteristic of the deposit is the high-grade (ave. 1.34 % Cu) with bornite, chalcopyrite and chalcocite as main ore minerals. Through a field and petrographic investigation, three phases of hydrothermal evolution have been recognized at the Nulasai Cu deposit, including the stage I magnetite – quartz ± chalcopyrite ± bornite veins, the stage II calcite – barite ± chalcopyrite ± chalcocite ± pyrite ± bornite veins, and the stage III calcite – barite ± chalcopyrite ± sphalerite ± pyrite ± galena veins. Fluid inclusions of the stage I veins were captured under two-phase condition indicates that existence of both contemporaneous daughter mineral-bearing and liquid-rich fluid inclusions; they have an intermediate-high salinity (11.5 ∼ 38.5 wt% NaCl equiv) and homogenization temperature (266 ∼ 376 °C), with entrapment pressures from 47 to 167 bar (depth of approximately 0.5 to 1.7 km). The coexistence of vapor-rich and liquid-rich fluid inclusions was a defining feature of the stage II fluid inclusions, and they have an intermediate salinity (6.2 ∼ 10.7 wt.%NaCl equiv) and homogenization temperature (211 ∼ 287 °C), with entrapment pressures from 18 to 70 bar (depth of approximately 0.2 to 0.7 km). Fluid inclusions of the stage III veins were captured under two-phase condition, and intermediate-low salinity (3.2 ∼ 9.2 wt.%NaCl equiv) and homogenization temperature (155 ∼ 241 °C), with entrapment pressures of 6 to 32 bar (depth of 0.1 to 0.6 km). According to the stable isotope (O-H-C) data for the three mineralization phases, magmatic water containing organic carbon made up the majority of the early ore-forming fluids, whereas abundant meteoric water has been involved during the late stage of mineralization. Therefore, we suggest that fluid mixture between magmatic water and meteoric water may have led to simultaneous decrease of fluid temperature, salinity and their stable isotope values, and finally facilitates the Cu ore precipitation. This study emphasizes how high-grade Cu deposition in orogenic belts is initiated by fluid dilution.

Occurrence, distribution and fate of iodine during phosphate ore beneficiation process

Numerous beneficiation techniques, such as washing, grinding, flotation, digesting, and calcination, are used to concentrate the minerals found in phosphate rocks, which include apatite, carbonatites, and silicates. Significant iodine levels are often found in phosphate ore minerals, which have a distinctive geochemical occurrence. However, the exact occurrence and distribution of iodine in these minerals are not yet thoroughly understood. A study was carried out to investigate the iodine's distribution, occurrence modes (phases), and release rate in Moroccan phosphate as it undergoes the beneficiation process. The samples underwent a multi-analytical approach combining mineralogical and chemical characterization using ICP-MS, ICP-OES, XRD, elements titration, and Pearson correlation analysis for interelement relationships. Calcination, digestion, and Heavy liquid separation is used to study the fate of iodine. The analysis indicates that iodine is primarily found in fluorapatite, with local concentrations ranging from 35 to 130 ppm. The most enriched grains/zones are associated with fluorapatite, enriched in P2O5, F-. in addition, iodine is positively correlated with its main components, including P2O5, F-, SO3, Na2O, CaO, and REEs. The flotation and heavy liquid separation process used for calcite and silicate removal is acting as an iodine and P2O5 concentrator, given that 99 % of iodine occurs in the apatite phase. However, it has been demonstrated that iodine can be released during the digestion of phosphate rock. Where the initial iodine content is distributed among phosphoric acid, PG, and the gaseous phase, constituting 35 %, 25 %, and 40 %, respectively. Furthermore, the calcination of phosphate rock between 800–1000 °C shows that total iodine is released with gases in I2 form, leading to an increase in the concentration of iodine in the surrounding area. In this regard, an integrated pyrometallurgical process has been proposed for the valorization of iodine as silver iodide. This process involves trapping gaseous iodine in an alkaline solution, followed by precipitation, thereby contributing to the overarching objectives of the circular economy and environmental protection.

Evaluation of road roughness and its influence on operating parameters in open-pit mines

Hauling ore and waste rock is a major cost factor in open-pit mines, encompassing both road maintenance and off-road truck operation. Road maintenance costs are directly influenced by traffic volume and the size of trucks using the roads. Off-road truck operating costs are impacted by various factors, including those affecting their movement, such as the direct interaction between tires and the road surface. Tire-road interaction significantly affects rolling resistance. Rougher surfaces with deeper grooves caused by track sinks lead to higher rolling resistance. This study employed laser profiling to characterize the surface roughness of five mine haul roads in two large Brazilian iron ore mines. This study evaluated the impact of these road irregularities on various operating parameters for 240-ton off-highway trucks, including rolling resistance, average travel speed, travel time, productivity, and unit transport cost. The results indicate that a 10 cm increase in road surface roughness can lead to a significant increase in rolling resistance (up to 5%), a substantial decrease in average speed (25%), a notable increase in travel time (26%), a decrease in productivity (19%), and a corresponding increase in unit transport cost (21%).

Strategies for Sustainable Mine Reclamation: Case Study of the Meghahatuburu Iron Ore Mine

ABSTRACT The demand for raw materials is increasing rapidly, leading to higher production targets for mining industries. Currently, largescale opencast mining operations are causing extensive damage to forest areas, agricultural land, and various habitats for humans and animals. Despite these negative impacts, mining plays a crucial role in our national economy, serving as the second backbone of the country after agriculture. Given the inevitability of mining operations, it is essential to carry them out in a sustainable manner, minimizing or even eliminating environmental harm. This study focuses on the challenges associated with iron ore mining and emphasizes the significance of ecological restoration and land reclamation in mitigating environmental consequences. The focus of this research work is the implementation of a comprehensive procedural approach to achieve sustainable mine reclamation in an easy way. The primary objective is to restore the biodiversity of the Saranda Forest ecosystem. To accomplish this, a three-tier plantation model was adopted, involving the strategic planting of 2,664 trees and 3,136 herbs/shrubs in 1.5 hector degraded backfilled area. This initiative aims to rehabilitate the degraded land that has been adversely affected by mining activities.

Ore Characteristics and Distribution Based on Geological and Geophysical Features of the Tambang Sawah Low Sulfidation Epithermal Gold Prospect in Lebong District, Sumatra Island, Indonesia

Sumatra is recognized as one of the Indonesian islands with a big potential for mineral deposits particularly along the belt known as Neogene Sumatra gold axis. However, the publication of the gold resources is still restricted as regional/district scale maps or limited in some locations and internal company reports, hence, a detailed study on deposit scale remains limited. This study aims to document the deposit geology, ore characteristics and geophysical features of the Tambang Sawah prospect at Lebong district, Sumatra Island. The study was done by geological mapping, sampling, and analyzing of selected samples by petrographic, ore microscopic, X-Ray Diffraction, micro X-Ray Fluorescence and various geochemical analyses to identify ore characteristics. The geophysical survey was carried out using geomagnetic and induced polarization. Ore mineralization is manifested by various alteration types such as argillic, propylitic, and silicification, which suffered andesitic breccia and granite host-rocks. Gold mineralization is in the form of quartz veins with typical opening space filling textures such as colloform, crustiform, cockade, moss, comb, and brecciated. The main sulfides consist of pyrite, chalcopyrite, covelite, sphalerite and galena. Gold commonly occurs as free grains. Highest grade gold of up to 21.3 ppm is associated with colloform and cockade-crustiform quartz veins. Geophysical surveys indicate that gold mineralization is associated with low geomagnetic anomaly areas. The 3D modelling of the IP survey reveals that the ore mineralization may occur at 75m depth. Two target areas located at the northeastern and southwestern portions are recommended for a follow-up detailed exploration based on the mapped ore geology, ore characteristics, and geophysical anomalies.

Assessing Mining Performance Indicators in Relation to the SDGs: Development of a Guided Methodology and Its Application in an Iron Ore Mine

Assessing Mining Performance Indicators in Relation to the SDGs: Development of a Guided Methodology and Its Application in an Iron Ore Mine

Unusual spinel in the “Verde Prato” serpentinized peridotite

A petrographic study of “Verde Prato” (trade name of an ophiolitic serpentinised peridotite quarried in Tuscany) revealed, next to a relict Cr-spinel, another opaque ore mineral apparently containing ca.17 wt% SiO2. In order to unveil the origin of this anomalous composition, detailed SEM-EDS, μ-Raman spectroscopy and X-ray μ-diffraction investigations were undertaken, which provided useful but somehow contrasting indications. Therefore, in order to definitely unveil the nature of the unusual opaque mineral, a specific TEM study was undertaken. This showed the presence of submicroscopic euhedral Mn-Cr-Fe-spinels in a matrix of a 7 Å layer-silicate (Al-lizardite). Interesting, all the submicroscopic spinel grains were found to share the same crystallographic orientation, suggesting an origin from a single, larger, former crystal. This unusual type of alteration of the mantle spinel probably occurred on the ocean floor during the pervasive polyphase process of hydrothermal peridotite serpentinization. Overall, by mapping the different serpentinite microstructures and compositions, a polyphase serpentinization history consisting of at least eight different cycles has been suggested. Moreover, the spinel composition indicates that the alteration was accompanied by Mn-metasomatism, made possible by the close proximity of Mn-rich hydrothermal vents, such as “black smokers”.

Fifty-year population trajectory in a marginal American Pika (Ochotona princeps) population

Abstract The American Pika (Ochotona princeps) has been considered a species at risk due to warming temperatures associated with climate change. Many life-history attributes of pikas contribute to the sensitivity of pikas to warming temperatures. Repeated censuses of a marginal (warm, low-elevation) population of pikas at Bodie State Historic Park, California, conducted from 1972 to 2022, are presented to track the population trajectory of pikas for a time period predating recent awareness of global warming to the present day, thus giving a comprehensive portrayal of how American pikas may be responding to climate change. The northern constellation of anthropogenic habitat patches (mine ore dumps) showed no decline in percent of patches occupied or in total number of pika territories over time, suggesting that pikas in that area have not been at risk of extirpation resulting from climate change. In contrast, the pika population in the southern constellation of patches showed significant declines in percent of patches occupied and number of pika territories occupied. That area was unoccupied for about a decade beginning in 2006, but was recently recolonized from the northern constellation of patches. The most likely cause of the initial decline and transient extirpation in the south appears to result from fragmentation and stochastic population dynamics, independent of climatic factors that we investigated. Assessments of climatic impacts on American pikas should take into account the dynamics documented in the Bodie pika population and its resilience over time.

Removal of Rare Earth Elements from complex mixtures by using manganese ferrite nanoparticles: Optimization through surface response methodology

The crucial role of Rare Earth Elements (REEs) in the development of hi-tech in addition to their limited availability have urged countries to develop sustainable alternatives to their conventional primary sources (ore mining). Sorption technologies using magnetic materials such as spinel ferrite nanoparticles provide efficient removal of REEs from contaminated solutions and ease of separation through application of an external magnetic field. However, there is still limited knowledge available regarding the optimal operational conditions in which to use these materials, especially in complex aqueous mixtures with different REEs. In this study, we have used Surface Response Methodology (SRM) applied to MnFe2O4 nanosorbents to identify their ideal sorption conditions of pH (4–8), REEs concentration (1–5 μM) and sorbent mass (20–180 mg L−1) in a mixture of nine REEs in water samples of distinct salinity (NaCl: 0–30 g L−1). Our results indicated that high pH favored REEs sorption because of the material's surface charge, which promoted interactions with REEs ions at pH 6–8. Yttrium was the least removed element, but total removal was achieved for lowest REEs concentration using 151 mg L−1 of sorbent. High removals were also obtained for the concentration of 5 μM (100 % removal, except for Y and La). Salinity did not impair sorption significantly (<10 %), which was owed to the high sorbent mass used in those assays. An increase in sorbent mass and initial REEs concentration also promoted faster kinetics. The spinel type MnFe2O4 nanoparticles showed great promise in a realistic application, which is the next proposed step in this line of research.

“We are protectors, not protestors”: global impacts of extractivism on human–nature bonds

This article analyzes the global impacts of extractivism on human–nature bonds. To do so, we rely on socio-ecological conflict data from the Global Atlas of Environmental Justice. Over 1800 cases involving resistance to the destruction of nature, cultures, cosmologies, worldviews, ancestral origins, and sacred places are analyzed using log-linear regression compared to 1600 cases that do not report such loss. The impact is especially visible when mineral ores, plantation products, and crude oil are extracted. The results indicate that affected groups are Indigenous peoples, farmers, peasants, pastoralists, and religious groups. In conflict outcomes, 79% of cases with refusal of compensation indicate impacts on human–nature bonds. Furthermore, in those cases where assassinations of activists occurred, 68% have observed impacts on human–nature bonds. Protecting human–nature bonds is a critical component for achieving social, economic, and environmental sustainability and justice against extractivism embedded in colonial relations playing against such bonds and environmental protectors.

Evaluation of leaching parameters for dissolving Ni and Co from chromite overburden using acidophilic bacterial consortium

ABSTRACT The chromite mine of Sukinda Valley located in the Indian state Odisha produces a large amount of overburden during the mining of chromite ore. The overburden waste contains different valuable metals with very low concentrations. Its environmental metal leaching contaminates nearby water resources, which creates serious chaos in the local communities. However, the presence of Ni-oxide in the overburden makes it the only Ni resources of India. Therefore, an experimental attempt was made to evaluate the possibility of Ni recovery from the overburden. The physico-chemical analysis of the overburden sample showed that it contains 0.89 and 0.031% (w/w) of Ni and Co, respectively, which remain embedded within the goethite matrix. Bioleaching may be suitably applied to it. Therefore, bioleaching of Ni and Co from the overburden sample was conducted using an acidophilic bacterial consortium. Effect of leaching parameters like contact time, initial pH, temperature, Fe(II) addition, and pulp density was evaluated. Bioleaching of the overburden sample using the acidophiles was found to be effective. Further, all the leaching parameters showed positive effect on the bioleaching efficiency.

Assessment of vertical transport of PM in a surface iron ore mine due to in-pit mining operations

Particulate matter (PM) is the most prevalent pollutant associated with surface mining operations, adversely affecting the health of mine workers. Using a combination of low-cost PM sensors and portable sampling devices, this research quantified the PM concentration and factors influencing its vertical transport inside a 100 m deep surface iron ore mine.Transport of ore through off-road trucks accounted for ∼ 70 % of the in-pit emissions. Also, differential settling and varying meteorological parameters along the vertical extent of the mine resulted in the escape of 17 % of PM2.5-10, 43 % of PM1-2.5, and 69 % of PM1to the mine’s surrounding atmosphere. Iron ore and carbon particles were identified as the major constituents of the airborne PM. The findings of this study demonstrate the application of low-cost sensors in monitoring PM concentration along the vertical extent of the mine, which can ultimately provide exposure estimates to the mine workers at different working locations.