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The Wangjiazhuang Cu (‐Mo) deposit, located within the Zouping volcanic basin in western Shandong Province, China, is unique in this area for having an economic value. In order to expound the metallogenetic characteristics of this porphyry‐like hydrothermal deposit, a detailed fluid inclusion study has been conducted, employing the techniques of representative sampling, fluid inclusion petrography, microthermometry, Raman spectroscopy, LA‐ICP‐MS analysis of single fluid inclusions, as well as cathode fluorescence spectrometer analysis of host mineral quartz. The deposit contains mainly two types of orebodies, i.e. veinlet‐dissemination‐stockwork orebodies in the K‐Si alteration zone and pegmatitic‐quartz sulfide veins above them. In addition, minor breccia ore occurs locally. Four types of fluid inclusions in the deposit and altered quartz monzonite are identified: L‐type one‐ or two‐phase aqueous inclusions, V‐type vapor‐rich inclusions with V/L ratios greater than 50%–90%, D‐type multiphase fluid inclusions containing daughter minerals or solids and S‐type silicate‐bearing fluid inclusions containing mainly muscovite and biotite. Ore petrography and fluid inclusion study has revealed a three‐stage mineralization process, driven by magmatic‐hydrothermal fluid activity, as follows. Initially, a hydrothermal fluid, separated from the parent magma, infiltrated into the quartz monzonite, resulting in its extensive K‐Si alteration, as indicated by silicate‐bearing fluid inclusions trapped in altered quartz monzonite. This is followed by the early mineralization, the formation of quartz veinlets and dissemination‐stockwork ores. During the main mineralization stage, due to the participation and mixing of meteoric groundwater with magmatic‐sourced hydrothermal fluid, the cooling and phase separation caused deposition of metals from the hydrothermal fluids. As a result, the pegmatitic‐quartz sulfide‐vein ores formed. In the late mineralization stage, decreasing fluid salinity led to the formation of L‐type aqueous inclusions and chalcopyrite‐sulfosalt ore. Coexistence of V‐type and D‐type inclusions and their similar homogenization temperatures with different homogenization modes suggest that phase separation or boiling of the ore‐forming fluids took place during the early and the main mineralization stages. The formation P‐T conditions of S‐type inclusions and the early and the main mineralization stages were estimated as ca. 156–182 MPa and 450–650°C, 350–450°C, 18–35 MPa and 280–380°C, 8–15 MPa, respectively, based on the microthermometric data of the fluid inclusions formed at the individual stages. [ABSTRACT FROM AUTHOR]

Silicocarbonatites are carbonatite rocks containing > 20% silicate minerals. Their formation is not well understood due to low silica solubility in carbonatite melts and negligible amounts of silicate minerals on carbonatite melt cotectics at upper crustal conditions. We explore whether silicocarbonatites can be thought of as antiskarns: rocks formed by leaching of SiO2 from siliceous wall rocks by carbonatite melts, and its deposition as solid silicate minerals by reaction with chemical components already present in the carbonatite melt. Solid state thermodynamic modelling at 1–5 kbar and 500–800 °C predicts that calcite–dolomite–magnetite assemblages will transform to dolomite-free silicocarbonatites with an increase in silica contents. In sodic systems, the formation of aegirine and alkali amphiboles suppresses silica activity despite elevated silica contents. Therefore, dolomite remains stable, but Fe3+ is consumed, firstly from magnetite breakdown, and secondly by coupled Fe oxidation and reduction of CO2 to CO, CH4, and graphite, particularly at higher pressures. Despite a net increase in Fe3+/Fe2+, the system evolves to increasingly lower oxygen fugacity. In aluminous systems, nepheline indicates high temperatures whereas alkali feldspars form at lower temperatures. Modelling of potassic systems demonstrates stability of mostly phlogopite-rich biotites, leading to Fe2+ increase in all other carbonate and silicate phases. We find that perthites are expected in high pressures whereas two feldspars are more likely in lower pressures. Aspects of the clinopyroxene natural compositional trend (diopside to hedenbergite to aegirine) of carbonatite systems can be explained by silica contamination. Ferrous clinopyroxenes typically require low alumina and are predicted in potassic or low temperature sodic systems, primarily at mid to high pressures. Silica contamination permits the formation of silicocarbonatite-like assemblages in a way that is not limited by SiO2 solubility in carbonatite melts. Glimmerites and clinopyroxene-rich rocks (such as the ijolite series) that often occur around carbonatite rocks at the contact with silica-oversaturated wall rocks can be explained as the extreme end of silica contamination of carbonatite melts. Therefore, these clinopyroxenites and glimmerites can form solely via metasomatic processes without the presence of a silicate melt. [ABSTRACT FROM AUTHOR]

Coal is a solid combustible mineral, and coal-bearing strata have important hydrocarbon generation potential and contribute to more than 12% of the global hydrocarbon resources. However, the deposition and hydrocarbon evolution process of ancient coal-bearing strata is characterized by multiple geological times, leading to obvious distinctions in their hydrocarbon generation potential, geological processes, and production, which affect the evaluation and exploration of hydrocarbon resources derived from coaly source rocks worldwide. This study aimed to identify the differences on oil-generated parent macerals and the production of oil generated from different coaly source rocks and through different oil generation processes. Integrating with the analysis of previous tectonic burial history and hydrocarbon generation history, high-temperature and high-pressure thermal simulation experiments, organic geochemistry, and organic petrology were performed on the Carboniferous-Permian (CeP) coaly source rocks in the Huanghua Depression, Bohai Bay Basin. The oil-generated parent macerals of coal's secondary oil generation process (SOGP) were mainly hydrogen-rich collotelinite, collodetrinite, sporinite, and cutinite, while the oil-generated parent macerals of tertiary oil generation process (TOGP) were the remaining small amount of hydrogen-rich collotelinite, sporinite, and cutinite, as well as dispersed soluble organic matter and unexhausted residual hydrocarbons. Compared with coal, the oil-generated parent macerals of coaly shale SOGP were mostly sporinite and cutinite. And part of hydrogen-poor vitrinite, lacking hydrocarbon-rich macerals, and macerals of the TOGP, in addition to some remaining cutinite and a small amount of crude oil and bitumen from SOGP contributed to the oil yield. The results indicated that the changes in oil yield had a good junction between SOGP and TOGP, both coal and coaly shale had higher SOGP aborted oil yield than TOGP starting yield, and coaly shale TOGP peak oil yield was lower than SOGP peak oil yield. There were significant differences in saturated hydrocarbon and aromatic parameters in coal and coaly shale. Coal SOGP was characterized by a lower Ts/Tm and C31-homohopane22S/ (22Sþ22R) and a higher Pr/nC17 compared to coal TOGP, while the aromatic parameter methyl dibenzothiophene ratio (MDR) exhibited coaly shale TOGP was higher than coaly shale SOGP than coaly TOGP than coaly SOGP, and coal trimethylnaphthalene ratio (TNR) was lower than coaly shale TNR. Thus, we established oil generation processes and discriminative plates. In this way, we distinguished the differences between oil generation parent maceral, oil generation time, and oil production of coaly source rocks, and therefore, we provided important support for the evaluation, prediction, and exploration of oil resources from global ancient coaly source rocks. [ABSTRACT FROM AUTHOR]

The present study addresses transformation of physicochemical forms (species) of artificial radionuclides in bottom sediments (BS) of the Yenisei River after the shutdown of the reactors at the Mining-and-Chemical Combine (MCC) at Krasnoyarsk. The BS samples collected from the Yenisei at the MCC in 2018–2021 contained 60Co, 137Cs, 152Eu, 154Eu, 155Eu, and 241Am. The species of radionuclides were studied using sequential extraction procedure. Considerable proportions of 60Co (48–100%) and 137Cs (72–83%), which are still released to the Yenisei with controlled discharges, were irreversibly bound to BS mineral solids. The percentages of europium isotopes, which have not been released to the Yenisei as part of controlled discharges since 2013, were lower in the irreversibly bound fraction (4.6–9.3% of 152Eu), but their representation as relatively mobile species was more diverse compared to 60Co and 137Cs. Interestingly, some percentage of 152Eu (up to 15.5%) was retained in the most mobile, exchangeable, form. The species of 154Eu and 152Eu differed, which can be explained by dissimilar origins of these isotopes. Further research is needed to investigate the mechanisms of physicochemical transformation of radionuclides in BS that enable them to be present in mobile species over long time periods and mechanisms of immobilization of artificial radionuclides in the environment. [ABSTRACT FROM AUTHOR]

Materials based on Portland cement and concrete are widely used for radioactive waste solidification and construction of engineered safety barriers at radioactive waste repositories. As compared to other candidate matrices, cement also exhibits the potential for chemical immobilization by reacting with many radionuclides and binding them. The water permeation through the bulk of concrete leads to its degradation, to a change in the composition of its pore water, and to transformations of solid mineral phases constituting the concrete. The long-term degradation of concrete can be estimated using geochemical modeling. A procedure for forecasting the degradation of materials based on Portland cement concrete is described. The model takes into account the stages of cement hydration and chemical degradation. The geochemical changes in the course of concrete degradation were calculated using numerical modeling with the PhreeqC code. Schemes of the stepwise concrete degradation are considered for estimating the radionuclide transport. Relevant radionuclide distribution coefficients are applied to each stage. The duration of concrete degradation stages largely depends on the filtering water composition. [ABSTRACT FROM AUTHOR]

In this study, a novel numerical approach is proposed to characterize the dissolution of rock minerals and wormhole propagation in carbonate rocks using the Darcy scale model. Accordingly, only the spatial variables of the governing partial differential equations are discretized, while the time variable remains continuous. Consequently, the partial differential equations are turned into ordinary ones, which are then numerically solved by high-order Runge-Kutta methods. The proposed approach is verified against the analytical solution in a 1D core model. Afterwards, it will be utilized to investigate the effect of multiple transport and reaction phenomena on the matrix acidizing in 2D carbonate formations. Also, the staggered grid technique is employed to accurately predict the wormhole patterns during several injection regimes. Compared to the previous studies, the proposed numerical approach is less complicated and straightforward. Furthermore, the computational cost is more affordable. [ABSTRACT FROM AUTHOR]

The technical challenges associated with deep underground space activities have become increasingly significant. Among these challenges, one major concern is the assessment of rockburst risks and the instability of rock masses. Extensive research has been conducted by numerous scholars to mitigate the risks and prevent occurrences of rockburst through various assessment methods. Rockburst incidents commonly occur during the excavation of hard rock in underground environments, posing severe threats to personnel safety, equipment integrity, and operational continuity. Thus, it is crucial to systematically document real cases of rockburst, allowing for a comprehensive understanding of the underlying mechanisms and triggering conditions. This understanding will contribute to the advancement of rockburst prediction and prevention methods. Proper selection of an appropriate rockburst assessment method is a fundamental aspect in underground operations. However, there is a limited number of studies that summarize and compare different prediction and prevention methods of rockburst. This paper aims to address this gap by analyzing global trends using CiteSpace software since 1990. It discusses rockburst classification and characteristics, comprehensively reviews research findings related to rockburst prediction, including empirical, simulation, mathematical modeling, and microseismic monitoring methods. Additionally, the paper presents a compilation of current rockburst prevention measures. Notably, the paper emphasizes the significance of control strategies, which provide key insights into the effective utilization of stored energy within rock. Finally, the paper concludes by suggesting six directions for implementing intelligent management techniques to mitigate hazards during underground operations and reduce the probability of rockburst incidents. [ABSTRACT FROM AUTHOR]

The analytical hierarchy process (AHP) was employed to delineate the mineralisation potential across the notable schist belts in northwestern Nigeria. High-resolution aeromagnetic and aeroradiometric datasets were taken into consideration. This was achieved by using advanced signal enhancement techniques to study the structures, identify the hydrothermal alteration zones (that could serve as a pathway for mineralisation), and understand the geologic settings. Amongst the enhancement techniques are first vertical gradient, analytic signal, CET grid analysis and porphyry, Euler deconvolution, and K/Th ratio. The analytic signal reveals lithologic contact, structures and anomalous occurrences that aided the classification of the site into three magneto-lithologic zones: high (> 0.094 nT/m), intermediate (0.028 to 0.094 nT/m), and low magnetic zones (< 0.028 nT/m). The high magnetic zones (HMZ) were considered the main magnetic source outlines, which are inferred to be dominantly intrusive zones for hydrothermal activities. The 3-dimensional Euler deconvolution reveals highly magnetic and intrusive depth sources to be within the range of < 100 to 500 m. The Centre for Exploration Targeting (CET) grid technique revealed the structural distribution from which the lineament density map was produced. The orientations of the prevalent structural anomalies are E-W, NE-SW, WNW-ESE and NW–SE, with similar orientations observed from the first vertical gradient and the analytic signal. The highly dense structural zones coincide with the high magnetic zones and high-frequency amplitudes of the analytic signal and the vertical gradient map, respectively. Additionally, the CET porphyry detects the centres of the intrusive porphyries to be within zones of high lineament density. This reveals that the mineralisation potential of the area is structurally controlled. On the other hand, radioelement maps (eU, eTh, and K%) and ternary maps were used for lithological classification. The radiometric ternary map revealed the highly radioactive zones and the superior concentration of individual radioelements in their respective areas. The K/eTh ratio map delineates highly potassic alteration zones. The AHP model and weighted overlay tool were employed to integrate the analytic signal, lineament density, and K/Th ratio. Consequently, the mineralisation potential of the study site was revealed and classified into high, moderate, and low. This result was validated using known mine sites. There was a total agreement, with 87.5% of mines plotting within the high mineralisation potential class and 12.5% in the moderate class. Promising targets were identified for development. [ABSTRACT FROM AUTHOR]

A solid solution of the mineral feiite (Fe3TiO5) was recently discovered in a shock-induced melt pocket of the Shergotty martian shergottite. It is particularly interesting for its potential as an indicator of pressure-temperature (P-T) and oxygen fugacity in martian crustal and mantle material. To date, complete crystallographic analysis of feiite has not been conducted, as the mineral was previously analyzed by electron backscatter diffraction on micrometer-size grains (Ma et al. 2021). Here we report a convergent crystal-structure model for feiite based on synchrotron single-crystal X-ray diffraction data collected on three grains of feiite synthesized at 12 GPa and 1200 °C. Feiite adopts the CaFe3O5 structure type (Cmcm, Z = 4), which is composed of two octahedral M1 and M2 sites and one trigonal prismatic M3 site (M = metal) in a ratio of 1:2:1. The three feiite grains with composition Ti0.46–0.60Fe3.54–3.40O5 were best modeled by substituting Ti4+ into only the octahedral M2 site, accounting for 30% of this site. Comparisons of the measured average bond lengths in the coordination polyhedra with the optimized Ti4+–O, Fe2+–O, and Fe3+–O bond lengths suggest that ferrous iron occupies the trigonal M3 site, while iron is mixed valence in the octahedral M1 and M2 sites. The Ti4+ and Fe3+ content constrained by our crystal-chemical analyses suggests that at least ~30% of the available iron must be ferric (i.e., Fe3+/Fetotal = 0.3) for the sample synthesized at 12 GPa and 1200 °C and higher P-T conditions may be needed to form the end-member feiite F e 3 2 + T i O 5 [ABSTRACT FROM AUTHOR]

This study examined the radioactivity levels of soil samples within selected solid mining sites in Nigeria using high-purity germanium (HpGe) detector. Sixty soil samples in all were collected from the 10 solid mineral mining sites investigated and six samples were collected as control samples from non-mining environment for analyses. The results of the activity concentration values obtained for 40K, 226Ra and 232Th are 100.22 Bq kg−1, 33.15 Bq kg−1 and 77.31 Bq kg−1, respectively. The 226Ra and 40K activities were found to be within the United Nation Scientific Committee on the Effects of Atomic Radiation acceptable permissible limit, but the 232Th mean value was above the permissible limit of 30 Bq kg−1 for the public. In comparison, 40K, 226Ra and 232Th soil samples mean activity concentrations were higher than the control soil samples values by 48.6%, 43.7% and 62.3%, respectively. The results of estimated radiation hazard indices indicate average values of 150.72 Bq kg−1, 68.40 nGyh−1 n G y h − 1 , 83.65 µSvy−1 and 454.70 µSvy−1 for the Radium Equivalent (Raeq R a e q ), Absorbed Dose Rate (D), Dose Equivalent (AEDE) and Annual Gonadal Equivalent Dose (AGED), respectively. The mean values for External Hazard Indices (Hex, Hin), Representative Gamma index ( I γ ) and Excess Life Cancer Risk (ELCR) were 0.41, 0.50, 1.06 and 0.29 × 10−3, respectively. The statistical analysis shows positive skewness. [ABSTRACT FROM AUTHOR]

In order to interpret the airborne magnetic data and to evaluate the approximate location, depth, and geometry of the magnetic sources within Obudu area using standard Euler deconvolution method, high resolution aeromagnetic data over the area was processed digitally and analyzed using Oasis Montaj 8.5 software. Data analysis and enhancement techniques including reduction to equator, horizontal derivative, first and second vertical derivatives, upward continuation and regional-residual separation were carried out. Standard Euler deconvolution for structural indices of 0, 1, 2, and 3 were obtained. Results show that the total magnetic intensity ranges from -122.9nT to 147.0nT, regional intensity varies between -106.9nT to 137.0nT, while residual intensity ranges between -51.5nT to 44.9nT indicating the masking effect of deep-seated structures over surface and shallow subsurface materials. Results also show that the positive residual anomalies have a NE-SW orientation which coincides with the trend of major geologic structures in the area. Euler deconvolution for all the structural indices has depth to magnetic sources ranging from <0m to >2000m. Interpretation of the various structural indices revealed the locations and depths of the source bodies and the existence of geologic models including sills, dykes, pipes, and spherical structures. This area is characterized by shallow basement materials and represents a good prospect for solid mineral exploration. [ABSTRACT FROM AUTHOR]

We use a coupled thermodynamically consistent framework to model reactive chemo-mechanical responses of solid solutions. Specifically, we focus on chemically active solid solutions that are subject to mechanical effects due to heterogeneous stress distributions. The stress generation process is driven solely by volume changes associated with the chemical processes. We use this model to describe the underlying physics during standard geological processes. Furthermore, simulation results of a three-species solid solution provide insights into the phenomena and verify the interleaving between mechanical and chemical responses in the solid. In particular, we show the evolution of the thermodynamic pressure as the system goes to a steady state. [ABSTRACT FROM AUTHOR]

X-ray computed tomography has established itself as a crucial tool in the analysis of rock materials, providing the ability to visualise intricate 3D microstructures and capture quantitative information about internal phenomena such as structural damage, mineral reactions, and fluid-rock interactions. The efficacy of this tool, however, depends significantly on the precision of image segmentation, a process that has seen varied results across different methodologies, ranging from simple histogram thresholding to more complex machine learning and deep learning strategies. The irregularity in these segmentation outcomes raises concerns about the reproducibility of the results, a challenge that we aim to address in this work. In our study, we employ the mass balance of a metamorphic reaction as an internal standard to verify segmentation accuracy and shed light on the advantages of deep learning approaches, particularly their capacity to efficiently process expansive datasets. Our methodology utilises deep learning to achieve accurate segmentation of time-resolved volumetric images of the gypsum dehydration reaction, a process that traditional segmentation techniques have struggled with due to poor contrast between reactants and products.We utilise a 2D U-net architecture for segmentation and introduce machine learning-obtained labelled data (specifically, from random forest classification) as an innovative solution to the limitations of training data obtained from imaging. The deep learning algorithm we developed has demonstrated remarkable resilience, consistently segmenting volume phases across all experiments. Furthermore, our trained neural network exhibits impressively short run times on a standard workstation equipped with a Graphic Processing Unit (GPU). To evaluate the precision of our workflow, we compared the theoretical and measured molar evolution of gypsum to bassanite during dehydration. The errors between the predicted and segmented volumes in all time-series experiments fell within the 2% confidence intervals of the theoretical curves, affirming the accuracy of our methodology. We also compared the results obtained by the proposed method with standard segmentation methods and found a significant improvement in precision and accuracy of segmented volumes. This makes the segmented CT images suited for extracting quantitative data, such as variations in mineral growth rate and pore size during the reaction. In this work, we introduce a distinctive approach by using an internal standard to validate the accuracy of a segmentation model, demonstrating its potential as a robust and reliable method for image segmentation in this field. This ability to measure the volumetric evolution during a reaction with precision paves the way for advanced modelling and verification of the physical properties of rock materials, particularly those involved in tectono-metamorphic processes. Our work underscores the promise of deep learning approaches in elevating the quality and reproducibility of research in the geosciences. [ABSTRACT FROM AUTHOR]

Mineral carbonation is a technology for capturing and storing CO2 in solid minerals. When mineral carbonation is used to produce construction materials, the quantification of the CO2 uptake of these products is of the utmost importance, as it is used to calculate the CO2 footprint of the product and/or carbon offset. The CO2 uptake is generally determined by measuring the CO2 content of a material before and after accelerated carbonation. This approach, however, does not take hydration and dehydroxylation reactions into account that may occur during carbonation, and it can therefore under- or overestimate the CO2 uptake. Thus, a more accurate and practical method to determine CO2 uptake, which also accounts for hydration and dehydroxylation reactions, is proposed in this paper. This method is based on analytical methods to determine the dry mass and the CO2 content of the solid products before and after carbonation, and on the calculation of the CO2 uptake by the following equation: CO2 uptake (wt.%) = CO2 carbonated (wt.%) × (weight after carbonation (g)/weight before carbonation (g) − CO2 initial (wt.%), with CO2 carbonated being the CO2 content in g/100 g dried carbonated material, and CO2 initial being the CO2 content in g/100 g dried initial material, i.e., before carbonation. The "weight before carbonation" is the dry weight of the initial material, and the "weight after carbonation" is the product's dry weight after carbonation. In this paper, we show that up to 44% under- or overestimation of CO2 uptake can occur when hydration and dehydroxylation reactions are not taken into account during mineral carbonation. [ABSTRACT FROM AUTHOR]

Determining mineral prospecting targets is crucial for mineral prediction and evaluation. In this study, an evaluation index system for solid mineral exploration and metallogenic target assessment was established using the Analytic Hierarchy Process (AHP) for the Naoniushan area (China). Furthermore, an integrated model combining geology–aerogeophysics–geochemistry was developed for copper, lead, zinc, silver, and other polymetallic deposits. The information content of each index in the model was reasonably assigned, and the mineral prospecting targets in the central and southern parts of the Daxinganling were recommended. By focusing on the copper polymetallic mineral prospecting target in the Naoniushan area, this paper demonstrates that the AHP method can comprehensively consider various influencing factors and their interactions, realize a reasonable division of the optimal mineral prospecting target, and reflect the key factors affecting the mineral prospecting target to a certain extent. Importantly, this approach reduces the influence of human subjective factors, and the optimization results are objective and scientifically grounded. [ABSTRACT FROM AUTHOR]

the domestic (Polish) lignite deposits, including the bełchatów deposit, are classified as multi-mineral and multi-raw materials. Ensuring the possibility of using a significant part of all minerals present in this type of deposits should be a matter of priority for mines. Over several dozen years of operation, the bełchatów lignite Mine, based on its own experience in documenting and exploiting both the main mineral and accompanying minerals, as well as rock mass components that are not solid minerals, this mine has developed a new approach to the problem of the comprehensive use of deposit resources. the content of the article is an attempt to answer the question: do the applicable laws guarantee a comprehensive and rational use of mineral deposits whose resources are non-renew- able? On the example of the area of the bełchatów lignite deposit, the comprehensive and rational use of mineral resources was analysed. It was indicated that the reasons for their use result from the lack of appropriate organizational, economic and financial solutions. Particular attention was paid to the need to modify the licensing procedures for prospecting, documenting and extracting minerals. It seems reasonable to introduce multi-resource concessions, which are an important element of the circular economy. therefore, proposals were formulated regarding the introduction of additional legal regulations and instruments of an economic and financial nature. these would be able to guarantee the comprehensive and rational use of most mineral resources. [ABSTRACT FROM AUTHOR]

Cordierite (2MgO·2Al 2 O 3 ·5SiO 2) is a kind of important ceramic with low thermal expansion coefficient and low dielectric constant. In this study, the influence of raw material compositions and various sintering temperatures on the synthesis mechanism and reaction path of cordierite were studied. The results reveal that the binary compounds forsterite and magnesia-alumina spinel are firstly generated in the low-temperature section while using pure single oxide materials. Then, forsterite and magnesia-alumina spinel are respectively combined with Al 2 O 3 and SiO 2 to form cordierite. The reaction of magnesia-alumina spinel with SiO 2 to form cordierite requires a higher temperature. The addition of CaO and TiO 2 tends to form low melting point substances, thus promoting the formation of cordierite phase. This study has a certain guiding significance for the cordierite synthesizing from natural minerals and solid wastes. [Display omitted] [ABSTRACT FROM AUTHOR]

Matrix acidizing is vital to enhance the production of tight carbonate formations. In weak carbonate rocks or acid over-dissolution, the rock is prone to failure upon developing wormholes. Strengthening agents can play a significant role in mitigating failure and supporting more extended productivity. In this study, we tested 0.1 M and 0.2 M zinc sulfate (ZnSO4) and 0.5 M diammonium phosphate ((NH4)2HPO4) as strengthening agents, which change the dominant host mineral into harder ones. Both agents were tested on two different types of acidized (i.e., wormholed) carbonate rocks, specifically Austin chalk and Indiana limestone. The impulse hammer and acoustics measurements evaluated the carbonate rocks' mechanical properties before and after the treatment. In addition, scanning electron microscopy energy-dispersive X-ray spectroscopy (SEM–EDS) and scanning electron microscopy (SEM) were used to affirm the change of rock mineralogy into harder minerals after the treatment. The chemical treatment caused no noticeable change in the wormhole size and shape, as revealed by the scanned micro-computed tomography (micro-CT) images. The chemical treatment of the samples was conducted by core flooding the plugs at high pressure and temperature with 4–5 pore volumes of the chemicals and leaving them in the treatment solution for 72 h. As a result of the formation of harder minerals, the mechanical properties after the treatment showed improvement. Zinc sulfate raised the surface rock hardness of limestone by 16%, while diammonium phosphate showed a 30% increase when evaluated with the same technique. The most noticeable improvement happened to chalk after treatment with diammonium phosphate. Chalk impulse hammer hardness almost quadrupled with the diammonium phosphate. The acoustics measurements showed a similar result to the impulse hammer through an increase in the dynamic Young's modulus and a decrease in Poisson's ratio. [ABSTRACT FROM AUTHOR]

Solid minerals are ubiquitous and common deposits on Ti-lined process vessels in the hydrometallurgical industry. This work revealed the effects of inert solid deposits on the corrosion behaviour of Ti-2 in high acidity and highly oxidising leaching solutions. It was found that the deposit-covered Ti-2 had a higher corrosion rate (CR) than bare Ti-2. CR increased with increasing deposit thickness (up to 6 cm) and temperature. Solid deposits mainly affected the corrosion process of Ti by limiting the mass transfer of the oxidising Fe(III) from the bulk solution to the underlying Ti, thus affecting the stability of the protective passive film, and resulting in an accelerated passive CR. High temperatures and solid deposition are both commonly encountered in the hydrometallurgical industry, and their combination may significantly limit the maximum service temperature of Ti-equipment, implying that there is a risk in using Ti-components under such conditions. [ABSTRACT FROM AUTHOR]

Mined Trona is a naturally occurring inorganic salt that is consumed by humans for diverse purposes in Nigeria. Due to the increase in consumption rates of these salts following a renewed government interest in solid minerals exploration and exploitation, it is imperative to assay its radiological content. Reconnaissance survey revealed that the most commonly used Trona varieties were: Farar Kanwa, Jan Kanwa, Dan Libya, Ngurnu, Manda, Farar Balma, Jar Balma and Yar Agadez. Samples of the identified Trona varieties were purchased from markets within Zaria, Nigeria. The samples were analysed using NaI (Tl) gamma ray spectrometry system. Radium equivalent activity (Raeq), annual effective dose (AED), Internal and Alpha hazard Indices (Hin and Iα) and total cancer risks (TCR) were used to assess the radiological safety of its consumption. The activity concentration of 238U (226Ra); 232Th and 40K varied widely and had an average ± error values of 42.904 ± 4.54 Bq/kg, 11.96 ± 1.41 Bq/kg and 455.28 ± 10.56 Bq/kg respectively. Raeq, AED, Iα, Hin and TCR were estimated at 95.07 ± 63.10 Bq/kg, 68.52 ± 52.53µSv/y, 0.21 ± 0.23, 0.37 ± 0.27 and (390.57 ± 299.44) × 10 − 06 respectively; which were by far less than the US EPA and UN SCEAR acceptable thresholds. It was established that the threshold consumption rate is 40 Kg/year and any value slightly higher than the threshold values will be associated with a significant radiological health risk. Therefore, at the present consumption rate of Trona in Nigeria, there is no cause for radiological concern. [ABSTRACT FROM AUTHOR]

The consumption of bottled natural mineral water has become more popular in Turkey due to the faith about the helpful medicinal and therapeutic impacts of mineral waters including various dissolved minerals. However, mineral water derived from groundwater contains natural radioactive radon gas which is one of the important sources of natural radiation. In this study, the activity levels of radon in forty-nine bottled natural plain and fruit-flavoured mineral water samples of twenty-two commercially brands sold in Turkish markets were determined using an active radon gas monitoring system. The pH, conductivity, salinity, and total dissolved solids of mineral water samples were also measured using standard laboratory methods. The total annual effective dose due to ingestion and inhalation of radon in mineral water samples was estimated for infants, children, and adults to assess the health risk caused by internal exposure. The activity concentrations of radon measured in mineral water samples varied from 30.6 to 57.6 mBq L−1 with an average of 43.1 ± 6.1 mBq L−1. The average total annual effective dose was found as 0.42, 0.26 and 0.36 µSv for infants, children and adults, respectively. All measured radon concentrations and estimated annual effective dose values are within the within recommended limits by the WHO and European Union for drinking water. It can be concluded that the effective radiation dose from the radon in bottled natural mineral water samples investigated is very low and creates a negligible health risk for the public. [ABSTRACT FROM AUTHOR]

One of the most complicated tasks of analytical control of copper ores is determination of mineral forms of copper. Currently, this is aided by iodometric and atomic absorption methods with preliminary leaching of various mineral forms, characterized by complicated sample preparation and very time-consuming analysis. The most universal method of determination of mineral composition of solid samples is X-ray diffraction analysis; however, significant variations of phase composition of copper ores, overlapping reflections of various phases, and existence of amorphous phase and structural defects necessitate the development of specialized approaches. In this work, the existence of amorphous phase is taken into account by direct calculation of weight fractions of crystalline phases by the G factor method. It is proposed to determine the total copper content by the X-ray fluorescence method. Methodological approaches have been developed based only on X-ray methods, excluding leaching and dissolution of samples, and making it possible to detect primary and secondary copper sulfides by calibrating characteristics (3 min), as well as complete phase composition at the stage of routine analysis (10–15 min) and for research purposes (15–20 min). [ABSTRACT FROM AUTHOR]

Bauxite residue (BR), also known as red mud, is a byproduct of the alumina production using the Bayer process. This material is not used to make iron or other iron-containing products worldwide, owing to its high content of sodium oxide and other impurities. In this study, we investigated the hydrochemical conversion of goethite (FeOOH) to magnetite (Fe3O4) in high-iron BR from the Friguia alumina refinery (Guinea) by Fe2+ ions in highly concentrated alkaline media. The simultaneous extraction of Al and Na made it possible to obtain a product containing more than 96% Fe3O4. The results show that the magnetization of Al-goethite and Al-hematite accelerates the dissolution of the Al from the iron mineral solid matrix and from the desilication product (DSP). After ferrous sulfate (FeSO4·7H2O) was added directly at an FeO:Fe2O3 molar ratio of 1:1 at 120 °C for 150 min in solution with the 360 g L−1 Na2O concentration, the alumina extraction ratio reached 96.27% for the coarse bauxite residue size fraction (Sands) and 87.06% for fine BR obtained from red mud. The grade of iron (total iron in the form of iron elements) in the residue can be increased to 69.55% for sands and 58.31% for BR. The solid residues obtained after leaching were studied by XRD, XRF, TG-DTA, VSM, Mössbauer spectroscopy, and SEM to evaluate the conversion and leaching mechanisms, as well as the recovery ratio of Al from various minerals. The iron-rich residues can be used in the steel industry or as a pigment. [ABSTRACT FROM AUTHOR]

The results of fundamental and applied research aimed at ensuring safe working conditions in terms of the thermal factor in the development of deep deposits of solid minerals are presented. The current parameters of the thermal regime of operating deep mines and mining plants in Russia are given. A description of the methodology developed for determining effective measures for managing the thermal regime of mining enterprises, mathematical models, and tools used to calculate the parameters has been given. Promising directions of research in the field of ensuring safe and efficient mining in conditions of unfavorable thermal conditions at great depths have been presented. [ABSTRACT FROM AUTHOR]

The regulation of anthropogenic carbon dioxide (CO 2) is an urgent issue – continuously increasing atmospheric CO 2 from burning fossil fuels is leading to significant warming and acidification of the surface ocean. Timely and effective measures to curb CO 2 increases are thus needed in order to mitigate the potential degradation of natural ecosystems, food security, and livelihood caused by anthropogenic release of CO 2. Enhanced rock weathering (ERW) on croplands and hinterlands may be one of the most economically and ecologically effective ways to sequester CO 2 from the atmosphere, given that these soil environments generally favor mineral dissolution and because amending soils with crushed rock can result in a number of co-benefits to plant growth and crop yield. However, robust quantitative evaluation of CO 2 capture by ERW in terrestrial soil systems that can lead to coherent policy implementation will require an ensemble of traceable mechanistic models that are optimized for simulating ERW in managed systems. Here, we present a new 1D reactive transport model – SCEPTER. The model is designed to (1) mechanistically simulate natural weathering, including dissolution/precipitation of minerals along with uplift/erosion of solid phases, advection plus diffusion of aqueous phases and diffusion of gas phases, (2) allow targeted addition of solid phases at the soil–atmosphere interface, including multiple forms of organic matter (OM) and crushed mineral/rock feedstocks, (3) implement a range of soil mixing regimes as catalyzed by soil surface fauna (e.g., bioturbation) or humans (e.g., various forms of tilling), and (4) enable calculation of solid mineral surface area based on controlled initial particle size distributions coupled to a shrinking core framework. Here we describe the model structure and intrinsic thermodynamic/kinetic data, provide a series of idealized simulations to demonstrate the basic behavior of the code, and evaluate the computational and mechanistic performance of the model against observational data. We also provide selected example applications to highlight model features particularly useful for future prediction of CO 2 sequestration by ERW in soil systems. [ABSTRACT FROM AUTHOR]

In the article are discussed new ways of lithium-containing raw materials processing: spodumene, lepidolite and other types of solid minerals and methods of sorption and extraction of lithium from brines, as well as technologies for extracting useful components from electroplating pairs of lithium-bearing materials. Despite the satisfactory technological indicators of traditional methods of extracting lithium from raw materials, researchers consider it necessary to improve processing schemes in order to increase the yield of lithium in products and reduce economic costs to provide the market with cheap lithium products. The proposed new developments provide for the acceleration of the process of thermal decryption of spodumene, reduction of processing stages to reduce the technical and economic indicators of the process, effective purification of lithium solutions from impurities to increase the purity of the obtained lithium salts, selective sorption or extraction of lithium ions, as well as the extraction of lithium from spent lithium batteries in order to return them to economic circulation. [ABSTRACT FROM AUTHOR]

Gasification and combustion are two common methods for Zhundong (ZD) coal utilization. In the present study, it was intended to investigate the thermal transformation of Na in ZD coal at the Lurgi fixed bed gasifier (Lurgi) and circulating fluidized bed boiler (CFBB). To this end, raw coal samples before gasification and gasified slags were gathered from Lurgi, and the raw coal before combustion, burned slag, and fly ash were collected from CFBB. The occurrence form of Na was analyzed by extraction experiments, and the samples were analyzed by inductively coupled plasma‐optical emission spectrometry (ICP‐OES), X‐ray diffraction (XRD), and scanning electron microscopy (SEM). The obtained results revealed that insoluble Na in Lurgi slag exceeded 90% under the high‐pressure gasification process. It was found that the high temperatures and high in Lurgi intensify the conversion of sodium to Na2Ca3Si2O8 and NaAlSiO4. The performed analyses revealed that the insoluble Na content in CFBB slag and fly ash was above 92%, and Na2SiO3 and NaAlSi3O8 were the main sodium minerals in CFBB solid residue. It was found that 76.64% of the initial Na content of raw coal in Lurgi migrated into slag after the gasification process, which was 7.05% higher than the sum of slag and fly ash in CFBB after combustion. During the sodium thermal transformation in Lurgi and CFBB, high pressures significantly reduce the release of gaseous Na from coal ash so more Na was retained in slag. [ABSTRACT FROM AUTHOR]

Coal is the primary energy source in China, while underground mining is the mainstream way of coal mining. By triggering surface movement and deformation, underground mining can cause damage to arable land, buildings, roads, and so on, which is detrimental to the ecological environment in the mining area. In order to assess the severity of damage caused by this to the ground buildings and ecological environment in the mining area, it is necessary to predict mining-induced surface subsidence before the mining activities are carried out. Currently, the most used prediction method is the Probability Integral Method. It is based on probabilistic theory to mathematically demonstrate that the surface downwelling caused by underground extraction conforms to normal distribution. However, there is a lack of validation with measured subsidence basin data. Since the 1960s, China has been paying increased attention to the study of mining subsidence. However, there are still few network stations built across China to monitor subsidence basin. Herein, SPSS software is applied to re-analyze these valuable historical data. By analyzing the observation results and comparing them with the calculation results as obtained by using the probability integral method, it can be found out that the surface subsidence in the center of the subsidence basin conforms to normal distribution, not the subsidence at the edge of the subsidence basin. Therefore, it is inevitable for errors to occur at the edge of the subsidence basin when the normal distribution function is used as the mining influence function to calculate the surface subsidence. This conclusion is expected to provide practical reference for the prediction of surface subsidence in coal mines, and this experience can be extended to the mining of other solid minerals. [ABSTRACT FROM AUTHOR]

Explosives are commonly used in the mining industry to extract minerals from hard rock deposits. Therefore, an efficient explosive should ensure that the appropriate blast outcome is achieved, taking into account the desired rock-breaking parameters and the costs of drilling and blasting works. Depending on the type of deposit and follow-up processes, a proper blast result may be characterized by fragmentation, muckpile shape, overbreaks, etc. Industry has struggled to respond to the demand for bulk emulsion explosives with improved energetic parameters, having so far been unable to do so safely, effectively, and cost-efficiently. Methods of improving blasting parameters mainly rely on introducing a variety of additives to the emulsion explosive formulation during production, which creates additional hazards at that stage. Alternative, safe methods of achieving an improved energetic performance of emulsion explosives are, therefore, highly desirable. This paper is focused on one such proposed method as a continuation of previous research works and the performance of a novel bulk emulsion formulation under real mining conditions during the firing of mine faces is described. The tests included density measurements over time, measurements of impact and friction sensitivity, measurements of the detonation velocity in blastholes, determination of brisance via Hess test, and analysis of rock fragmentation. Results were compared with those obtained with a commercially available bulk emulsion explosive, highlighting that the performance improvement achieved by the proposed emulsion modification method is not limited to artificial test conditions, but translates well into actual application conditions. [ABSTRACT FROM AUTHOR]

Hydrothermal treatment (HT) can effectively dehydrate and reduce oily sludge (OS) volume, but the resulting hydrothermal oily sludge (HOS) presents greater challenges for washing than the initial oily sludge (IOS). This study examines the effects of HT on OS by analyzing changes in water, oil, and solid. Results indicate that HT considerably decreases the water content in OS while increasing resin and asphaltenes contents. In addition, condensation, side-chain scission, and oxidation reactions occur during the HT process, resulting in coking, agglomeration, and an increase in oxygen-containing groups. This increase, further confirmed by X-ray photoelectron spectroscopy (XPS), enhances the interaction between oil and solids. Calcite, the most prevalent solid-phase component, may form a calcium bridge with the oxygen-containing groups. Moreover, HT reduces the solid particle size, thereby increasing the oil–solid contact area. Interestingly, the process of deasphalting diminishes the interaction between oil and solids, facilitating sludge washing. After washing, the residual oil content in HOS is reduced to less than 0.34%. This study elucidates why HOS is challenging to separate from oil and solids and introduces a novel method that combines dodecylbenzene sulfonic acid (DBSA)-assisted heptane deasphalting with conventional washing techniques. This method shows promise for applications in OS affected by weathering processes. [Display omitted] • Hydrothermal treatment strengthen interaction between crude oil and mineral solids. • Dodecylbenzene sulfonic acid (DBSA)-assisted heptane deasphalting weaken interaction between asphaltenes and mineral solids. • DBSA can not only disperse asphaltenes but also sludge particles, promoting the deasphalting process of oily sludge. • Residual oil content of deasphalted sludge is lower than 0.34% using conventional washing. [ABSTRACT FROM AUTHOR]

In a multi-station fast pyrolysis reactor, the influence of oil shale ash on the potassium retention characteristics of corn stalk under different pyrolysis conditions was investigated in the study. The influence of oil shale ash on the potassium migration process during the pyrolysis of corn stalk was elucidated by analyzing changes in the composition and concentration of potassium and other minerals in the pyrolysis semi-coke of corn stalk. This analysis was conducted using inductively coupled plasma emission spectroscopy (ICP-AES), X-ray diffraction (XRD), and complemented by thermodynamic simulation. The findings demonstrate that oil shale ash could fix potassium in corn stalk, and the potassium retention rate peaked when the oil shale ash additive amount reached to 10 %. This is because the silica-aluminum compounds in the oil shale ash reacts with potassium salts in a semi-molten state to produce KAl 2 Si 3 AlO 10 (OH) 2 , KAlSi 3 O 8 , and KAlSi 2 O 6.When the amount of oil shale ash added is increased to 15 %, KAlSi 3 O 8 and KAlSi 2 O 6 in the semi-coke would continue to react with Al 2 O 3 and SiO 2 , converting to KAl 2 Si 3 AlO 10 (OH) 2. Thermodynamic simulation results indicate that the alkali metal potassium in corn stalk semi-coke mainly existed in potassium metasilicate, potassium feldspar, and leucogranite. In order to enhance potassium fixation in corn stalk, the addition of oil shale ash would promote the transformation of potassium-solidifying minerals from potassium metasilicate to potassium feldspar and leucite in the semi-coke. • Oil shale ash show a remarkable capacity to fixing potassium during biomass pyrolysis. • Potassium retention ratio is the highest when 10 % oil shale ash is added. • The main solid potassium mineral, KAlSi 3 O 8 , is converted to KAl 2 Si 3 AlO 10 (OH) 2. [ABSTRACT FROM AUTHOR]

[Display omitted] • A bract-like nodule structure biomineralized MnOx was prepared by Lactobacilli. • Biomineralized MnOx facilitated microbial nitrification and denitrification. • Mn-N cycling is achieved by Mnammox and Mn-based autotrophic denitrification. In recent years, manganese (Mn) has emerged as an accelerator for nitrogen metabolism. However, the bioactivity of manganese is limited by the restricted contact between microbes and manganese minerals in the solid phase and by the toxicity of manganese to microbes. To enhance the bioactivity of solid-phase manganese, biomineralized manganese oxide (MnOx) modified by Lactobacillus was introduced. Nitrogen removal performance have confirmed the effective role of biomineralized MnOx in accelerating the removal of total inorganic nitrogen (TIN). Metagenomic analysis has confirmed the enhancement of the nitrogen metabolic pathway and microbial extracellular electron transfer (MEET) in biomineralized MnOx treatment group (BIOA group). Additionally, the enrichment of manganese oxidation and denitrification genus indicates a coupling between nitrogen metabolism and manganese metabolism. One point of views is that biomineralized MnOx-mediated nitrogen transformation processes could serve as a substitute for traditional nitrogen removal processes. [ABSTRACT FROM AUTHOR]

Three-dimensional/four-dimensional (3D/4D) geoscience modeling with the multi-disciplinary intersection of geosciences has been used as the basis for mineral exploration and the extraction of geosciences information for mineral resources assessment. The geological concept model can be quantitatively analyzed by typical deposit research with an exploration engineer; thus, 3D/4D models can be built, simulated, and integrated via multisource geosciences datasets or big data from the field survey and the analysis of geosciences methods. With the development of high-precision geological observation technology, in situ mineral microanalysis technology, isotope geochemical analysis technology, deep geophysical exploration technology, deep drilling, real-time mining, remote sensing high-resolution hyperspectral image technology, and supercomputer and industrial intelligence, geoscience has entered an era of big data and artificial intelligence in the 21st century. [Extracted from the article]

In this study, a temperature programmed oxidation-infrared (TPO-IR) technique was improved and applied in the analysis of sulfur occurrence and genesis in phosphate rock. Phosphate rocks from three regions (KYP, ZJP, and WAP) were selected for the detection of sulfur species by TPO-IR combined with XRD, SEM, EDS, and XPS characterization. TPO-IR results show that the total sulfur contents of the three phosphate rocks were 2.14% for KYP, 1.18% for ZJP, and 1.06% for WAP. In the low-temperature area (<1000°C), TPO-IR detected that both KYP and WAP contain FeS with a characteristic temperature of about 513°C and their contents were 9.22‰ and 0.64‰, respectively. In high-temperature areas (>1000°C), the TPO-IR curves suggest that sulfate is the main sulfur species in the three phosphate rocks. Typically, the characteristic temperature near 1070oC belongs to MgSO4, and the characteristic temperature near 1290°C belongs to CaSO4. Due to the incomplete TPO-IR database of sulfur reference materials at present, it is not possible to assign all sulfur species in high-temperature areas. However, in a sense, this research provides theoretical basis and experimental support for the application of the TPO-IR technique for the detection of sulfur species in other solid minerals. [ABSTRACT FROM AUTHOR]

The use of a high volume of industrial solid waste mineral admixture and hybrid fiber can greatly reduce the amount of cement in mortar or concrete, improve its performance, ensure the service properties of mortar or concrete, and reuse industrial solid waste to reduce the environmental burden, which has significant research significance. In this paper, the mechanical properties, wear resistance and microstructure of hybrid fiber-reinforced mortar (HFRM) with a high content of industrial solid waste mineral admixture were systematically studied under different water/binder ratios. Mineral admixtures include fly ash, silica fume and granulated blast furnace slag (slag). The total content of hybrid glass fiber (GF) and polypropylene fiber (PPF) was 2% by volume fractions, and six different water/binder ratios ranging from 0.27 to 0.62 were used. The following conclusions were drawn: fibers have a significant negative effect on the properties of mortars with a low water/binder ratio (w/b = 0.27) and high content of mineral admixtures. In general, the effect of adding hybrid fiber on improving the wear resistance of mortar is more obvious. The average residual weight of hybrid fiber-reinforced mortar is the highest after the wear resistance test. Comprehensively considering the compressive strength, flexural strength, wear resistance and microstructure of the mortar samples, G8PP2-0.40 is the optimal mix ratio. At this time, the replacement rates of fly ash, silica fume and slag are: 20%, 5% and 30%, the water/binder ratio is 0.40, and the content of GF and PPF is 1.6% and 0.4%, respectively. [ABSTRACT FROM AUTHOR]

Graph HT ht (12) Finally, a feature observed at both temperatures is the inward increase in the width of chlorite coronas around olivine. [Extracted from the article]

The article explores micro-features of beryl gemstones, focusing on their crystal structure, formation environments, and commonly encountered inclusions. Topics include the various beryl species found in nature, their geological origins, and the types of inclusions typically observed in natural beryl gems, excluding synthetic and treated varieties.

Zinc plant leach residues (ZPLRs), particularly those produced using old technologies, have both economic importance as secondary raw materials and have environmental impacts because they contain hazardous heavy metals that pose risks to human health and the environment. Therefore, the extraction and recovery of these metals from ZPLRs has both economic and environmental benefits. In this study, we investigated the removal of lead (Pb) and zinc (Zn) from ZPLRs by alkaline (NaOH) leaching and the concurrent cementation of dissolved Pb and Zn using aluminum (Al) metal powder. The effects of the leaching time, NaOH concentration, solid-to-liquid ratio (S/L), and dosage of Al metal powder on the extraction of Pb and Zn were investigated. Pb and Zn removal efficiencies increased with increasing NaOH concentrations and decreasing S/Ls. The Pb and Zn removal efficiencies were 62.2% and 27.1%, respectively, when 2.5 g/50 mL (S/L) of ZPLRs were leached in a 3 M NaOH solution for 30 min. The extraction of Pb and Zn could be attributed to the partitioning of these metals in relatively more mobile phases—water-soluble, exchangeable, and carbonate phases—in ZPLRs. Around 100% of dissolved Pb and less than 2% of dissolved Zn were cemented in leaching pulp when Al metal powder was added. Minerals in the solid residues, particularly iron oxides minerals, were found to suppress the cementation of extracted Zn in leaching pulp, and when they were removed by filtration, Zn was recovered by Al metal powder via cementation. [ABSTRACT FROM AUTHOR]

To eliminate the consequences of accidental spill of phenol, the results of neutralization of soils contaminated with phenol are presented. As for the analysis of soils by the geological-lithological section it was found that in areas of phenol contamination the soil has a surface soil-plant layer with a thickness of about 0.5m, then there is a heavy clay layer with a thickness of up to 7.0 m and finally a sand layer saturated with groundwater is observed. It revealed that according to physical and mechanical properties, the solid mineral phase of the soil corresponds to a hard plastic and semi-solid consistency of clays. It showed that the filtration of water through the bottom and walls on the area of the former burial of the tank is complicated because of closer to zero water permeability of soil strata due to clay rock. Mineralogical and chemical composition of soils contaminated with phenol is determined. An environmentally safe method of neutralizing phenol-containing soils is developed with a neutralizing composition based on quicklime and bentonite which simplifies the neutralization method of soils contaminated with phenol. Environmental safety was observed in the absence of phenol in water extracts from soils and the in treatment process permissible for the environment рН. Essence of proposed method lies in chemical inactivation of phenol based on its transformation into slow-moving water-insoluble compound - calcium phenolate. Decontamination product of phenol-containing soil is the smallest capsules comprising soil particles and immobilized phenol in the form of calcium phenolate. Material of the capsule represented by calcium hydroxide is neutralized over time by bentonite and СО2 from air resulting in the formation of hydrophobic silicate and calcium carbonate which gives capsules high strength properties. The research into the neutralized phenol containing soil for phenol in water extracts showed that the proposed method is simple, ecologically safe, causes no recontamination of environment with pollutants and provides the phenol content in soils within MAC. [ABSTRACT FROM AUTHOR]

Regulation of anthropogenic carbon dioxide (CO2) is an urgent issue-continuously increasing atmospheric CO2 from burning fossil fuels is leading to significant warming and acidification of the surface ocean. Timely and effective measures to curb CO2 increases are thus needed in order to mitigate the potential degradation of natural ecosystems, food security, and livelihood caused by anthropogenic release of CO2. Enhanced rock weathering (ERW) on croplands and hinterlands may be one of the most economically and ecologically effective ways to sequester CO2 from the atmosphere, given that these soil environments generally favor mineral dissolution and because amending soils with crushed rock can result in a number of co-benefits on plant growth and crop yield. However, quantitative evaluation of CO2 capture by ERW in terrestrial soil systems to date has been conducted with tools that are mechanistically very simplified and/or allow limited flexibility. With the goal of working towards a more mechanistically grounded understanding of the geoengineering potential of terrestrial ERW, we developed new 1D reactive transport model - SCEPTER. The model is designed to: (1) mechanistically simulate natural weathering, including dissolution/precipitation of minerals along with uplift/erosion of solid phases, advection plus diffusion of aqueous phases and diffusion of gas phases; (2) allow targeted addition of solid phases at the soil-atmosphere interface, including multiple forms of organic matter (OM) and crushed mineral/rock feedstocks; (3) implement a range of soil mixing regimes as catalyzed by soil surface fauna (e.g., bioturbation) or humans (e.g., various forms of tilling); and (4) enable calculation of solid mineral surface area based on controlled initial particle size distributions coupled to a shrinking core framework. Here we describe the model structure and intrinsic thermodynamic/kinetic data, provide a series of idealized simulations to demonstrate the basic behavior of the code, and evaluate the computational and mechanistic performance of the model against observational data. We also provide selected example applications to highlight model features particularly useful for future prediction of CO2 sequestration by ERW in soil systems. [ABSTRACT FROM AUTHOR]

Vanadium is a multivalent element that may speciate as V2+; V3+; V4+ and V5+ in silicate and oxide phases. The relative abundance of V in planetary materials can be used as a proxy for oxygen fugacity (fO2) when its partitioning behavior has been calibrated with controlled laboratory experiments. Here we present the results of 20 piston-cylinder experiments executed over a 10-log unit range of fO2 at temperatures from 800 to 1230 °C, at 1.8–2 GPa, to quantify the partitioning of V between garnet, clinopyroxene, rutile and hydrous silicate melt under conditions relevant to eclogite melting in subduction zones. In all experiments, the partitioning of V between phases is controlled nearly equally by fO2 and by temperature (and/or compositional effects that are directly related to temperature). Vanadium is most compatible in experimental rutile, followed by clinopyroxene, then garnet. Calculated mineral/melt partition coefficients are ≥ 1 for all three phases in our experimental series. The high compatibility of V in eclogitic minerals results in negligible mass transfer of V during eclogite melting under all fO2 conditions investigated. Oxidized species of V are more soluble in rutile compared to garnet and clinopyroxene, leading to a linear increase in rutile/cpx and rutile/garnet inter-mineral partition coefficients as fO2 increases. We calibrate the partitioning of V among rutile-cpx and rutile-garnet pairs as an fO2 proxy for natural rocks and test its application to eclogitic xenoliths from the Koidu kimberlite suite (Sierra Leone). Our application yields spurious fO2 values for Koidu, indicating the V systematics of natural systems are likely much more complex than predicted by our experiments. Further work is needed to characterize the partitioning of V between eclogitic minerals over an extended range of mineral solid solutions, pressures, and temperatures before a V-oxybarometer may be applied to natural metamorphic systems with confidence. [ABSTRACT FROM AUTHOR]

Zeolites contribute significantly to the fields of chemical engineering, pharmaceuticals, and environmental protection. However, their synthesis usually involves chemicals for which reason the development of low-cost and eco-friendly synthesis methods is important. In this study, two solid wastes (coal fly ash, gasification slag) and one mineral (kaolin) were used as Si and Al sources, while diatomite was added as an auxiliary Si source, to synthesize the zeolite analcime via a hydrothermal method. The obtained analcime was upgraded, resulting in high purity and a high Si/Al molar ratio. The upgraded analcime was used to synthesize Cu-SSZ-13 catalysts by the inter-zeolite transformation method. By comparing the primary products synthesized from different raw materials, it was found that the appropriate Si/Al molar ratio and fewer impurities are key factors for the crystallinity of the resulting product. In addition, the zeolite SSZ-13 synthesized from the upgraded analcime had a higher utilization rate of Al element and smaller sizes. The Cu-SSZ-13 catalyst synthesized with the addition of diatomite (route 2) exhibited a high conversion of NO and selectivity to N 2. The as-synthesized Cu-SSZ-13 catalyst had more isolated Cu2+ species and acidic sites, possibly due to the high Al content. This work provides a method for the modification of zeolites based on solid waste and minerals for use in wider applications. [Display omitted] • Cu-SSZ-13 is synthesized using solid waste/mineral in a two-step hydrothermal process. • Diatomite in the initial hydrothermal activation enhances Si/Al ratio and purity of zeolite ANA. • Diatomite addition enhances Al conversion, acidity and isolated Cu2+ in Cu-SSZ-13 synthesis. [ABSTRACT FROM AUTHOR]

• The two-scale continuum model is employed for capturing mass, momentum, and energy transfer and updating rock property parameters and acid fluid transport and reaction process parameters during the acid stimulation process. • The core-scale model is expanded to consider the specific composition of solid minerals, which enables an investigation into the influence of mineral composition heterogeneity. • A heterogeneity generation tool is developed coupling with the open-source geostatistical program to generate random seeds producing different heterogeneous parameters with spatial-correlation characteristics. Acid stimulation within carbonate rocks represents a crucial aspect of reactive flow applications in subsurface porous media and has been widely used in carbonate reservoir development attributed to its rapid effectiveness and cost-efficiency. This study is motivated to investigate further the impact of rock heterogeneity on the acid stimulation process. The two-scale continuum model is employed for capturing mass, momentum, and energy transfer during the acid stimulation process. The core-scale model is expanded to consider the specific composition of solid minerals, including reactive minerals such as calcite and dolomite and non-reactive ones like quartz and clay. A heterogeneity generator is developed by coupling with the open-source geostatistical program to produce different heterogeneous parameters using random seeds with varying spatial correlation lengths. Sensitive cases are performed to present an investigation into the influence of mineral composition and matrix heterogeneity on the acid stimulation process. Results show that the typical results of acid stimulation are closely tied to different heterogeneity conditions. The optimum conditions for acid stimulation are sensitive to the concentration of reactive components. The optimum acid injection rate declines as dolomite content increases, while the corresponding acidizing breakthrough volume reduces with higher calcite levels. The presence of mineral layers, especially in horizontal distributions, complicates acid fluid efficiency due to the competitive reaction between calcite and dolomite. Compared to the heterogeneous distribution of minerals, matrix heterogeneity plays a critical role in acid fluid consumption efficiency. Increasing heterogeneity leads to significant reductions in breakthrough volumes, largely governed by the correlation length. [ABSTRACT FROM AUTHOR]