The method of dividing the “three zones” of spontaneous combustion in goaf by oxygen volume fraction is the most widely used and effective method at present. However, the oxygen volume fraction method does not consider the influence of methane concentration in goaf, which is only applicable to low-gas goaf, not high-gassy goaf. In this work, the oxidation behavior and kinetics parameters of a lean

Both seismic observations of dense low shear velocity regions and models of magma ocean crystallization and mantle dynamics support enrichment of iron in Earth’s lowermost mantle. Physical properties of iron-rich lower mantle heterogeneities in the modern Earth depend on distribution of iron between coexisting lower mantle phases (Mg,Fe)O magnesiowüstite, (Mg,Fe)SiO3 bridgmanite, and (Mg,Fe)SiO3 post-perovskite

The Duobaoshan (DBS)-Tongshan (TS) porphyry Cu–(Mo) deposit (4.4 Mt Cu, 0.15 Mt Mo) is located in the northeastern part of the central Asian orogenic belt (CAOB) in northeastern China. It is hosted by early Ordovician dioritic to granodioritic intrusions which are characterized by the subduction-related geochemical signatures including high concentrations of large ion lithophile elements (LILEs) and

The paper presents the results of research on rare earth elements (REY) and selected radionuclides in barren rocks deposited on a heap at a mine belonging to the Polish Mining Group (the largest producer of hard coal in EU countries). The maximum concentration of REEs determined in silstones was 261.6 mg/kg and in sandstones 221.2 mg/kg. The average uranium and thorium content in silstones was 6.8

An ab initio density functional theory method (DFT) with D3 dispersion corrections (DFT-D3) was employed to study the 64 possible models of the structure of hectorite intercalated with tetramethylammonium (TMA) cations with the aim to find the additional information about the structure for the energetically most suitable mutual arrangement of the TMA cations. The complex analysis of total energies

Mineral identification is an important part of geological analysis. Traditional identification methods rely on either the experience of the appraisers or the various measuring instruments, and the methods are either easily influenced by appraisers’ experience or require too much work. To solve the above problems, there are studies using image recognition and intelligent algorithms to identify minerals

Determining aqueous sulfate sources in terrestrial cold environments can provide an insight into the surface hydrological conditions and sulfur cycle on Mars. In this study, we analyzed sulfur and oxygen isotope compositions of secondary sulfate salts (e.g., gypsum, thenardite) in the surficial sediments and soils of the McMurdo Dry Valleys (MDV), Antarctica to determine contributions of sulfate from

Techinantitla building complex, in the Amanalco neighborhood of the ancient city of Teotihuacan, is famous for the iconography and quality of the mural paintings found in this site. A significant part of this heritage has been lost due to looting. In recent years, an interdisciplinary research project was developed to study the limited patrimony that was left. As part of this study, we first employed

Geological carbon capture and sequestration (CCS) is a promising technology for curbing the global warming crisis by reduction of the overall carbon footprint. Degradation of cement wellbore casings due to carbonation reactions in the underground CO2 storage environment is one of the central issues in assessing the long-term success of the CCS operations. However, the complexity of hydrated cement

In situ analyses of trace elements and rare-earth elements (REEs) were performed by use of laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS) on scheelite samples from the Yingzuihongshan tungsten deposit in western Inner Mongolia Autonomous Region, China. The contents of trace elements Nb, Ta and Mo of scheelite indicate that the ore-forming fluid is magmatic hydrotherm and is

Fluid inclusions were studied in rocks from different wells from the Barnówko–Mostno–Buszewo (BMB), the largest oil field in Poland and from the Lubiatów field. Sampling was performed at depths between about 3120–3220 m and 3221–3256 m, respectively. Different minerals (dolomite, calcite, anhydrite, quartz) reveal the presence of aqueous (AQFI) and hydrocarbon (HCFI) inclusions, the differentiation

Montmorillonite is one of the principal mineralogical phases in clay minerals, where its interaction with water and other molecules represents one of the most important aspects and properties for basic science and specific applications. In fact, montmorillonite has many uses in various scientific and technological fields, ranging from environmental remediation to ceramics, food science, and construction/building

The purpose of this study is to explore the degree and spatial distribution of dust heavy metal pollution in Tianshui City, the health risks, and the sources of heavy metals. The geoaccumulation index and health risk assessment are used to study pollution levels and human health risks, and Cu, Zn, and Pb pollution are found to be serious. The total exposure of children to dust and heavy metals is 8

The depletion of ore deposits, the increasing demand for raw materials, the need to process low-grade, complex and finely disseminated ores, and the reprocessing of tailings are challenges especially for froth flotation separation technologies. Even though they are capable of handling relatively fine grain sizes, the flotation separation of very fine and ultrafine particles faces many problems still

Soil fertility is determined by biological diversity at all levels of life, from genes to entire biocenoses. The aim of this study was to evaluate bacterial diversity in soil contaminated with Cd2+, Co2+ and Ni2+ and sown with Brassica napus. This is an important consideration because soil-dwelling microorganisms support phytoremediation and minimize the adverse effects of heavy metals on the environment

The effects of flotation operation parameters, including froth depth, air flowrate, and frother dosage, on the froth and collection zone recovery and the flowrate of particles into the froth phase were investigated in a 10 m3 industrial cell. The results showed that froth recovery increases upon increasing air flowrate and frother dosage, as well as reducing froth depth. While all tested parameters

Waste rock can contain high concentrations of deleterious trace elements, which upon oxidation can be released, having a significant impact on water quality. Therefore, knowledge about their occurrence and overall mobility is crucial to ensure suitable environmental protection measures. Sulfide-rich waste rock was characterized and quantified using automated mineralogy (QEMSCAN). Selected pyrite grains

The existence of the weak interlayer in the roadway surrounding rock mass presents a huge threat to the stability of the underground structure and the safety of mining engineering. By the characteristics of strong adaptability, superior anchoring effect and high efficiency of construction, rock bolt has been widely applied in mine reinforcement. However, the influence of the weak interlayer on the

Sandstone pore-plugging is a serious problem that bothers acid in situ leaching (ISL) uranium deposit, but currently, the mechanism of pore-plugging has not attracted much attention. In this study, using X-ray fluorescence, scanning electron microscope, optical microscope, and X-ray diffraction, we present both macro- and micro-evidence of pore-plugging occurred during acid in situ mining of sandstone

Shear deformation of a solid-fluid, two-phase material induces a fluid segregation process that produces fluid-enriched bands and fluid-depleted regions, and a crystallographic preferred orientation (CPO) characterized by girdles of [100] and [001] axes sub-parallel to the shear plane and a cluster of [010] axes sub-normal to the shear plane, namely the AG-type fabric. Based on experiments of two-phase

This study, carried out in Radzimowice, a historical As mining site, analyzed the speciation and mineralogical As forms in soils, in different locations, as related to rock weathering processes and associated environmental risk. Four soil groups, including those on mine dumps, and in the stream valley, as well as stream sediments, were examined. The screening performed on 52 samples showed an extremely

In this paper, the beneficiation of rejected phosphate washing sludges (Ps) was investigated using acid leaching methods. Chemical analysis showed that these sludges are a low-grade ore (15.84% P2O5). The optimum milling parameters have helped to increase the P2O5 grade to 18.51%. Then, the effects of three different organic acids (acetic, lactic, and citric acid), acid concentrations, reaction temperatures

Straight-chain alkanes (SCA) as collectors can effectively enhance the floatability of molybdenite. In a previous study, SCA were found to have an excellent adsorption effect on the molybdenite [001] surface (MS001), but they exhibited no adsorption behavior on the molybdenite [100] surface (MS100). However, other studies have shown that SCA could adsorb on MS100. In this paper, the underlying cause

In hard rock mining, sensor-based sorting can be applied as a pre-concentration method before the material enters the mill. X-ray transmission sensors have been explored in mining since 1972. Sorting ore of acceptable grade and waste material before processing at the mill can reduce the amount of tailings per unit of valuable metal in the mining operation and have many economic benefits. Ore samples

Volcanic rocks from deep-seated sources of the crust-mantle transition (CMT) are geochemically distinguished from those of ocean island basalts (OIB). Here, we report geochemical data on tectonic pseudotachylytes from the Main Sayan Fault (MSF) and volcanic rocks from the Kamar-Stanovoy Zone of Hot Transtension (KSZHT) that represent the deep-seated CMT magmatic sources in the central part of the Baikal

A significant part of the primary gold reserves in the world is contained in sulphide ores, many types of which are refractory in gold processing. The deposits of refractory sulphide ores will be the main potential source of gold production in the future. The refractory gold and silver in sulphide ores can be associated with micro- and nano-sized inclusions of Au and Ag minerals as well as isomorphous

The mine drainage of the Ibbenbüren anthracite coal mine is characterized by exceptionally high concentrations of dissolved iron and sulfate. The elevated position of the coal field with respect to the surrounding area makes the neighboring sediments an unlikely source of these elements. Accordingly, it has been hypothesized that interaction between infiltrating rainwater and the fractured overburden

Rare earth elements (REEs) are of great importance to modern society and their reliable supply is a major concern of many industries that utilize them in metal alloys, semiconductors, electrical equipment, and defense equipment. REEs in the coal waste have been revealed to be an alternative resource for REEs production. In this study, the extraction, recovery, and upgrading of the REEs from coal waste

The paper highlights the features of constructing a model of a wet semi-autogenous grinding mill based on the discrete element method and computational fluid dynamics. The model was built using Rocky DEM (v. 4.4.2, ESSS, Brazil) and Ansys Fluent (v. 2020 R2, Ansys, Inc., United States) software. A list of assumptions and boundary conditions necessary for modeling the process of wet semi-autogenous

Metakaolins (MKs) prepared from low-grade kaolins located in the Alvarães (A) and Barqueiros (B) regions of Portugal were used as the aluminosilicate source to compare their effect on the compressive strength and heavy metal adsorption of geopolymers. Natural zeolite, an inexpensive, efficient adsorbent, was used as an additive in formulations to enhance geopolymers’ adsorption capacities and reduce

A number of experiments were conducted on a laboratory batch impact crusher to investigate the effects of particle size and impeller speed on grinding rate and product size distribution. The experiments involved feeding a fixed mass of particles through a funnel into the crusher up to four times, and monitoring the grinding achieved with each pass. The duration of each pass was approximately 20 s;

Hyperspectral reflectance has the potential to provide rapid and low-cost mineralogical and chemical information that can be used to vector in mineral systems. However, the spectral signature of white mica and chlorite, despite numerous studies, is not fully understood. In this study, we review the mineralogy and chemistry of different white mica and chlorite types and investigate what mineralogical

Crop and livestock farming on contaminated soil has been found to induce the accumulation of trace elements in edible parts of plants, with subsequent risk to human and animal health. Since rice crop is a major source of energy in worldwide diets and is consumed by more than 3 billion people, the soil–rice pathway is regarded as a prominent route of human exposure to potentially toxic elements. This

In this paper, we provide insight into the evolution of syenite magmas based on geological data and petrographic, geochemical, and O-Nd isotope parameters of rocks of the Saibar intrusion located within the Minusinsk Trough, Altay-Sayan area. The intrusive suite includes predominant syenites, few bodies of melanocratic and leucocratic nepheline syenites (foyaites), and granites. In addition, dykes

The Sample Analysis at Mars (SAM) instrument on the Curiosity rover has detected evidence of oxychlorine compounds (i.e., perchlorates and chlorates) in Gale crater, which has implications for past habitability, diagenesis, aqueous processes, interpretation of in situ organic analyses, understanding the martian chlorine cycle, and hazards and resources for future human exploration. Pure oxychlorines

Space-borne multispectral and radar data were used to comprehensively map geological contacts, lithologies and structural elements controlling gold-bearing quartz veins in the Wadi Hodein area in Egypt. In this study, enhancement algorithms, band combinations, band math (BM), Principal Component Analysis (PCA), decorrelation stretch and mineralogical indices were applied to Landsat-8 OLI, ASTER and

Fly ash consists of mainly silt-size spherules that form during high-temperature coal combustion, such as in steam locomotives and coal-burning power plants. In the eastern USA, fly ash was distributed across the landscape atmospherically beginning in the late 19th century, peaking in the mid-20th century, and decreasing sharply with implementation of late 20th century particulate pollution controls

Ferroelastic twinning in minerals is a very common phenomenon. The twin laws follow simple symmetry rules and they are observed in minerals, like feldspar, palmierite, leucite, perovskite, and so forth. The major discovery over the last two decades was that the thin areas between the twins yield characteristic physical and chemical properties, but not the twins themselves. Research greatly focusses

Clay minerals are the signature of hydrothermal alterations related to fluid circulation in volcanic and crystalline rocks. In the French part of the Upper Rhine Graben, in the deep-seated granites, illitic minerals (illite and I/S mixed layers (ml)) are typical products of the structurally-controlled argillic alteration in the Paleozoic granitic basement. In the new Illkirch geothermal well, GIL-1

In this study, the treatment of acid mine drainage (AMD) using vertically flowing wetland was explored. The wetland was enriched with Vetiveria zizanioides as a decontaminating media and soil as the substrate. Water was percolated through the substrate and the throughput samples were collected and characterized every five days for a period of 30 days. The obtained results revealed a tolerant index

The Shuikoushan deposit is an economic ‘skarn-type’ polymetallic Pb-Zn deposit in South China. The deposit is located at the southern margin of the Hengyang basin in the northern part of the Nanling Range. Recently, economic Fe-Cu mineralization that occurs spatially connected to skarns along the contact zone between the granodiorite and limestones was discovered in the lower part of this deposit.

Silicas chemically modified with a number of sulfur-containing groups (mercaptopropyl, mercaptophenyl, dipropyl disulfide, thiadiazole thiol, dithiocarbamate and thiourea derivatives) were proposed for the separation and preconcentration of precious metals. These adsorbents quantitatively extracted precious metals from 0.5 to 4 M solutions of hydrochloric acid. It allowed their separation from high

Morocco is the leading producer of phosphate and its derivatives in the world with a total production of 35 Mt. However, the extraction and the valorization of this mine generate huge quantities of phosphate washing waste clay (PHWWC) that constitute a main environmental and economic concern. To facilitate this waste clay storage and handling, it is necessary to decrease its moisture content that represents

The sequential extraction procedure is used to reconstruct the processes of redistribution of uranium isotopes in the mineral phases of the aquifer of the Vendian sandy-argillaceous deposits developed in the coastal territory of the European North of Russia. This aquifer has large resources of drinking and mineral groundwater which, however, are used in extremely limited quantities. This is due to

Mechanistic understanding and prediction of solute adsorption from fluids onto mineral surfaces is relevant for many natural and technical processes. Mineral surfaces in natural systems are often exposed to fluids at non-equilibrium conditions resulting in surface dissolution reactions. Such reactions cause the formation of surface nanotopography and, consequently, the exposure of different types of

This research provides a characterization of ancient Roman mortars from “Villa del Capo di Sorrento” (commonly known as “Villa di Pollio Felice” or “Bagni della Regina Giovanna”). A deepened analysis of cementitious binding matrix and aggregates was conducted with the aims of determining possible sources of raw materials and the mix recipe, and to evaluate the minerogenetic secondary processes. Twenty

In addition to the known uses of natural clays, less publication attention has been paid to clays returned to the production process. Industrially recovered natural clays such as bricks, tiles, sanitary ceramics, ceramic roofing tiles, etc., are applicable in building materials based on concrete as an artificial recycled aggregate or as a pozzolanic type II addition. In this way, the building products

Many studies have shown that the average iron (Fe) isotope compositions of mantle-derived rocks, mantle peridotite and model mantle are close to those of chondrites. Therefore, it is considered that chondrite values represent the bulk Earth Fe isotope composition. However, this is a brave assumption because nearly 90% of Fe of the Earth is in the core, where its Fe isotope composition is unknown, but

Particle size distribution is an important soil parameter—therefore precise measurement of this characteristic is essential. The application of the widely used laser diffraction method for soil analysis continues to be a subject of debate. The precision of this method, proven on homogeneous samples, has been implicitly extended to soil analyses, but this has not been sufficiently well confirmed in

Jurassic dioritic to granitic igneous rocks extensively intrude into the southern Korean Peninsula, including the Yuseong area located at the boundary between the southern margin of the Gyeonggi Massif and the northern margin of the Okcheon Belt. In this study, the petrogenesis and sources of Jurassic igneous rocks in the Yuseong area were investigated. The U–Pb zircon age data from the Jurassic plutonic

The purpose of this study was to use fast geophysical measurements of soil magnetic susceptibility (κ) as supplementary data for chemical measurements of selected light rare earth elements (REEs) in soil. In order to ensure diversity in soil conditions, anthropogenic conditions and types of land use, seven areas were selected, all located in regions subjected to past or present industrial pollution

The equation of state (EoS) of a natural almandine74spessartine13pyrope10grossular3 garnet of a typical composition found in metamorphic rocks in Earth’s crust was obtained using single crystal synchrotron X-ray diffraction under isothermal room temperature compression. A third-order Birch-Murnaghan EoS was fitted to P-V data and the results are compared with published EoS for iron, manganese, magnesium

The design of cell-based flotation circuits is often completed in two distinct phases, namely circuit structure identification and equipment sizing selection. While recent literature studies have begun to address the implications of stochastic analysis, industrial practice in flotation circuit design still strongly favors the use of deterministic metallurgical modeling approaches. Due to the complexity

High-resolution images of Mars from National Aeronautics and Space Administration (NASA) rovers revealed mm-size loose haematite spherulitic deposits (nicknamed “blueberries”) similar to terrestrial iron-ooids, for which both abiotic and biotic genetic hypotheses have been proposed. Understanding the formation mechanism of these haematite spherules can thus improve our knowledge on the possible geologic

Growing public interest in getting information on the origin of raw materials used to manufacture goods for daily life has triggered the development of concepts to increase the transparency of raw material supply chains. Analytical proofs of origin (APOs) for raw materials may support those transparency concepts by giving evidence about the origin of a specific raw material shipment. For a variety

This paper describes and analyzes the Upper Jurassic (Lower Kimmeridgian) succession exposed in the Zakrzówek Horst, located in the Kraków area. Three distinguished facies types FT 1-FT 3 comprise several limestone varieties: sponge-microbial, pelitic-bioclastic, and partly dolomitized detrital-bioclastic. Their sedimentary environments varied from relatively deeper, attaining storm-wave base, to more

The chalcocite group minerals are widely distributed among different hydrothermally affected rocks, the oxidized zone of copper sulfide deposits, or may be even crystalline from supersaturated volcanic gases. Some of the chalcocite group minerals form the main Cu orebodies. Djurleite (Cu31S16) is a rare member of the chalcocite group, with a very complex structure. The physical and chemical similarities

Ultramafic lamprophyres (UMLs) are mantle rocks that provide important information about the composition of specific carbonate–silicate alkaline melts in the mantle as well as the processes contributing to their origin. Minerals of the spinel group typically occur in UMLs and have a unique “genetic memory.” Investigations of the spinel minerals from the UMLs of the Chadobets complex show the physicochemical

Feldspar for ceramic/glass industries requires sufficiently low content of harmful colourants (Fe-, Ti-, Mn-bearing mineral phases). Hydrothermally altered albite-rich granites are increasingly used as feldspar raw material nowadays; however, they are often marked by increased content of colourants, which must be removed during the processing of feldspar ore. Parallel to the content of colourants,

Composition of native gold and minerals in intergrowth with rhyolites of the Chudnoe Au-Pd-REE deposit (Subpolar Urals, Russia) was studied using optical microscopy, scanning electron microscopy, and electron microprobe analysis. Five varieties of native gold have been identified, based on the set of impurity elements and their quantities, and on intergrown minerals. Native gold in rhyolites from the