Hussein K. Mohammad, Amjad H. Albayati, Mazen J. Al-Kheetan
The durability of asphalt concrete is highly dependent on the geometry and mineralogy of coarse aggregates, yet their combined influence on mechanical and moisture resistance properties is still not fully understood. This study evaluates the effects of coarse aggregate geometry, specifically flat and elongated particle ratios and angularity, as well as mineral composition (quartz versus calcite), on asphalt mixture durability. The durability of mixtures was evaluated through Marshall properties as well as moisture susceptibility indicators, including the tensile strength ratio (TSR) and index of retained strength (IRS). Statistical analyses (ANOVA and <i>t</i>-tests) were also conducted to confirm the significance of the observed effects. Results showed that mixtures containing higher proportions of flat and elongated particles exhibited greater void content, reduced stability, and weaker moisture resistance, with the 1:5 flat-to-elongated ratio showing the most adverse impact (TSR 73.9%, IRS 69.2%). Conversely, increasing coarse aggregate angularity (CAA) enhanced mixture performance, with TSR values rising from 63.5% at 0% angularity to 81.2% at 100% angularity, accompanied by corresponding improvements in IRS. Mineral composition analysis further demonstrated that calcite-based aggregates achieved stronger bonding with asphalt binder and superior resistance to stripping compared to quartz-based ones. These findings confirm that aggregate geometry and mineralogy exert a decisive influence on asphalt mixture durability. They also highlight the need to revise current specifications that permit the use of uncrushed coarse aggregate in asphalt base courses, particularly when such layers may serve as surface courses in suburban or low-volume roads, where long-term resistance to moisture damage is critical.
The flotation of the graphite ore with fine embedded particle size is difficult to obtain high-grade graphite concentrate. The research on process mineralogy of graphite ores can lay a foundation for the experimental study of washability. This article analyzes the properties of the graphite ore in Jiangxi Province, and finds out the chemical composition, mineral composition, embedding characteristics of main minerals and the occurrence state of carbon and vanadium. The results show that graphite is mainly produced in flake, flake and fine plate shape in the ore. there are two types of graphite independently produced in gangue and graphite connected with pyrite and hematite. Graphite is fine-grained, mostly distributed in 0.013～0.052 mm. The harmful impurity metal minerals are mainly pyrite and hematite, and the gangue minerals with high content are quartz and muscovite. Carbon mostly exists in graphitic carbon, and a small amount of carbon exists in carbonate and carbonaceous substances such as calcite. Vanadium mainly occurs in mica minerals. The detailed process mineralogy research provides a scientific basis for the beneficiation process of graphite ores and the comprehensive recovery and utilization of graphite and vanadium.
<p>Marioantofilliite (IMA 2025-012), ideally [Cu<span class="inline-formula"><sub>4</sub></span>Al<span class="inline-formula"><sub>2</sub></span>(OH)<span class="inline-formula"><sub>12</sub></span>](CO<span class="inline-formula"><sub>3</sub></span>)<span class="inline-formula">⋅</span> 3H<span class="inline-formula"><sub>2</sub></span>O, is a new member of the hydrotalcite supergroup discovered in the Cu–Fe ore deposit of Monte Copello–Reppia, Graveglia Valley, Liguria, Italy. It occurs as globular aggregates up to 1 mm in diameter formed by <span class="inline-formula">µm</span>-sized prismatic crystals. The streak is light blue, and lustre is greasy. Calculated density is 2.825 g cm<span class="inline-formula"><sup>−3</sup></span>. Marioantofilliite is optically biaxial (–), with <span class="inline-formula"><i>α</i>=1.613(4)</span>, <span class="inline-formula"><i>β</i>=1.626(3)</span>, and <span class="inline-formula"><i>γ</i>=1.633(5)</span> (in 589 nm light). 2<span class="inline-formula"><i>V</i><sub>calc</sub></span> is 72°. It is distinctly pleochroic, ranging from colourless to pale blue. The empirical chemical formula of marioantofilliite (with rounding errors) is [Cu<span class="inline-formula"><math xmlns="http://www.w3.org/1998/Math/MathML" id="M19" display="inline" overflow="scroll" dspmath="mathml"><mrow><msubsup><mi/><mn mathvariant="normal">4.23</mn><mrow><mn mathvariant="normal">2</mn><mo>+</mo></mrow></msubsup></mrow></math><span><svg:svg xmlns:svg="http://www.w3.org/2000/svg" width="18pt" height="17pt" class="svg-formula" dspmath="mathimg" md5hash="89080c3eca3fd94521ffbc657cd70b55"><svg:image xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="ejm-37-733-2025-ie00001.svg" width="18pt" height="17pt" src="ejm-37-733-2025-ie00001.png"/></svg:svg></span></span>Mg<span class="inline-formula"><sub>0.02</sub></span>Al<span class="inline-formula"><sub>1.76</sub></span>(OH)<span class="inline-formula"><sub>12</sub></span>](CO<span class="inline-formula"><sub>3</sub>)<sub>0.82</sub></span>(SO<span class="inline-formula"><sub>4</sub>)<sub>0.01</sub></span>[Si(OH)<span class="inline-formula"><sub>6</sub></span>]<span class="inline-formula"><sub>0.05</sub>⋅3</span>H<span class="inline-formula"><sub>2</sub></span>O. Unit-cell parameters of marioantofilliite are <span class="inline-formula"><i>a</i>=5.590(3)</span>, <span class="inline-formula"><i>b</i>=2.9358(11)</span>, <span class="inline-formula"><i>c</i>=7.675(3)</span> Å, <span class="inline-formula"><i>β</i>=100.958(17)</span>°, and <span class="inline-formula"><i>V</i>=123.66(9)</span> Å<span class="inline-formula"><sup>3</sup></span>, with space group <span class="inline-formula"><i>C</i></span>2/<span class="inline-formula"><i>m</i></span> and <span class="inline-formula"><math xmlns="http://www.w3.org/1998/Math/MathML" id="M36" display="inline" overflow="scroll" dspmath="mathml"><mrow><mi>Z</mi><mo>=</mo><mn mathvariant="normal">1</mn><mo>/</mo><mn mathvariant="normal">3</mn></mrow></math><span><svg:svg xmlns:svg="http://www.w3.org/2000/svg" width="41pt" height="14pt" class="svg-formula" dspmath="mathimg" md5hash="828edc207d6ef858da7929ec24df6e45"><svg:image xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="ejm-37-733-2025-ie00002.svg" width="41pt" height="14pt" src="ejm-37-733-2025-ie00002.png"/></svg:svg></span></span>. The crystal structure was refined to <span class="inline-formula"><i>R</i><sub>1</sub>=0.0372</span> for 181 unique reflections with <span class="inline-formula"><i>F</i>>4<i>σ</i>(<i>F</i>)</span> and 23 refined parameters. It is topologically similar to that of other hydrotalcite-supergroup minerals and shows a distorted <span class="inline-formula"><i>{</i>001<i>}</i></span> brucite-like layer with Cu and Al statistically occupying an octahedrally coordinated <span class="inline-formula"><i>M</i></span>(1) site. The interlayer hosts disordered CO<span class="inline-formula"><sub>3</sub></span> and H<span class="inline-formula"><sub>2</sub></span>O groups. Marioantofilliite formed through the oxidative dissolution of primary Cu ores by mine drainage aqueous solutions and neutralization by gangue carbonates. Its name honours Mario Antofilli (1920–1983) for his contributions to the knowledge of the mineralogy of Liguria.</p>
Randa R. Elmorsi, Wael Abdel Wahhab, Khaled S. Abou-El-Sherbini
Abstract The mineralogical and chemical characteristics of sediments from Suez Bay (SB) were investigated and correlated with the key water quality parameters. These include polycyclic aromatic hydrocarbons (PAHs), dissolved total phosphorus (DTP), biological oxygen demand (BOD), and total dissolved solids (TDS). Samples were collected from offshore SB sediments, and mass loss at different temperatures (120, 550, and 1000 °C) was analyzed. X-ray fluorescence (XRF) was used to determine the concentrations of 40 elements. X-ray diffraction (XRD) was applied to identify crystalline mineral phases, while Fourier transform infrared (FTIR) spectroscopy was used to characterize functional groups associated with organic matter and carbonate inputs. Major mass losses at 550 and 1000 °C were confirmed to result from the decomposition of organic matter and carbonate minerals, respectively. High enrichment factors and strong inter-element correlations were observed, indicating common sources for specific element groups. A positive correlation was observed between PAHs in sediments and vanadium and nickel, suggesting a petrogenic origin. Significant positive correlations between barium, copper, lead, and zinc likely reflect contamination from ship maintenance activities at the Kazak Hassan West site, south of the SB. In contrast, dissolved total phosphorus (DTP) in the water showed a negative correlation with silica, highlighting their distinct source origins. These findings reveal the distribution patterns of pollutants and their interactions with sediment mineralogy and chemistry, contributing to a clearer understanding of environmental pollution in SB. The results emphasize the influence of proximity to the Suez Canal and human activities on the geochemical behavior of the SB sediments and overlying waters.
This is an article in the field of process mineralogy. The occurrence of zinc, associated dispersed elements Ga and Ge and the distribution characteristics of the main carrier minerals of a zinc ore in China are studied in detail by means of chemical analysis, microscope analysis and MLA mineral automatic quantitative technology.The results indicate that the zinc ore contains Zn 4.87%, Ga 4.10 g/t and Ge 59.00 g/t, no independent minerals of dispersed elements Ga and Geare found, Ga and Ge mainly occur in sphalerite. The theoretical recovery of Zn, Ga and Ge from sphalerite (including hemimorphite) are about 95%, 56% and 93% respectively. A small part of colloidal and fine grained sphalerite is difficult to obtain dissociation and easy to be lost in tailings, which has a certain effect on the recovery of zinc.
M. Lenin Lara Calderón, Inés del Pino, Sol López-Andrés
et al.
The relevance of the Franciscan community is reflected in the San Francisco church in Quito, which was built between 1535 and 1755. This architectural work belonging to the Franciscan complex was implanted on a plot of land with an area of 3.5 hectares and was one of the first buildings in the Audience of Quito. Eleven mortar samples that covered the walls of the central nave and side chapels were taken from the church’s main temple. The procedure proposed by the authors is based on a combined methodology following the standards and protocols for the less-invasive extraction of heritage samples. Tests included X-ray diffraction, petrography, and scanning electron microscopy with a microanalysis of the samples. Mortars with a rustic composition and rough manufacturing were identified to differentiate two types of mortar, one of earthen with volcanic aggregates and another of lime with volcanic aggregates. The mining data validated the existing historical documentation, the imaginary process, and the stages of the established constructions.
Eleonora Benà, Elena Spagnuolo, Antonio Piersanti
et al.
Abstract Numerous field and laboratory studies have been conducted to investigate the relationship between radon variation and seismic events, as well as the complex link between radon emission and rock deformation mechanisms. However, a clear understanding of this correspondence and systematic observations of these phenomena are still lacking, and recent experimental studies have yet to yield conclusive results. In this study, we investigate the possible relationships between radon migration dynamics and rock deformation at the micro-scale through laboratory experiments using the SHIVA apparatus under shear stress-controlled conditions and simultaneous high-resolution radon measurements. We studied the behaviour of three different lithologies to show that radon emission varies in response to rock deformation and this variation is highly dependent on the mineralogy and microstructure. This study represents the first attempt to define radon gas as an indicator of transient and rapid rock deformation at the micro-scale.
The paper characterizes REE mineralization from carbonaceous metapelites of the Paleoproterozoic Mikhailovka Formation, which is the most ancient gold-bearing horizon of the Lena province (Bodaibo district, Irkutsk region). The conditions of metamorphism of the studied samples do not exceed those of chlorite-muscovite subfacies of greenschist facies (ilmenite-pyrrhotite isograde). The metamorphic allanite is a main REE host, which crystallized before the last stage of plastic deformation and folding. The matter source for its formation is related to REE and Th absorbed on organic matter and clay minerals, as well as the detrital monazite. Late hydrothermal-metasomatic processes resulted in its replacement by hydroxycarbonates (hydroxybastnaesite, ancylite) and hydrous phosphates of light REEs (rhabdophane?), while Th precipitated as a hydrous silicate. Findings of low-temperature metamorphic monazite and xenotime are also described.
Loredana Brinza, Andreea Elena Maftei, Sorin Tascu
et al.
Abstract Two environmentally friendly organics (ethylenediaminetetraacetic acid, EDTA and its easier biodegradabe isomer, ethylenediamine-N, N′-disuccinic acid, EDDS) were used to dope calcium carbonate (CC) nanoparticles intending to increase their adsorptive properties and evaluate adsorption performance (uptake capacity and removal efficiency) for the persistent Reactive Yellow 84 azo dye. Easily synthesized nanomaterials were fully characterized (morphology and size, mineralogy, organic content, surface area, pore size and hydrodynamic diameter). RY84 removal was performed using two consecutive processes: photodegradation after adsorption. The CC-EDTA particles were most efficient for dye removal as compared to the plain and CC-EDDS particles. Adsorption kinetics and isotherms were considered for the CC-EDTA system. 99% removal occurred via adsorption on 1 g/L of adsorbent at 5 mg/L dye concentration and pH of 8 and it decreased to 48% at 60 mg/L. Maximum uptake capacity as described by Langmuir is 39.53 mg/g. As post-adsorption, under UVA irradiation, in the presence of 40 mmol/L H2O2, at dye concentration of 10 mg/L the highest degradation was 49.11%. Substantial decrease of adsorption (ca. 4 times) and photodegradation (ca. 5 times) efficiencies were observed in wastewater effluent as compared to distilled water. The results have important implications to wastewater treatments and appropriate decisions making for the choice of treatment process, process optimization and scaling up to pilot and industrial levels.
Nikolovski Zlatko, Isailović Jelena, Jeremić Dejan
et al.
The rare earth elements represent an increasingly more and more important industrial resource. The increased use may result in waste generation, and their impact upon the environment quality has not been studied sufficiently. Their interaction with soil has been studied in this paper. The Freundlich adsorption isotherm has been determined for lanthanum, erbium and gadolinium at three different soil types (humus, clay and sand type), whereas the sequential extraction at these soil types has been applied for lanthanum and neodymium. The interaction of certain rare earth elements with soil components has been tested as well as the quantity in which these elements are bound to soil and later on extracted in solutions. The objective was to determine the soil capacity for disposal, first of all, of the electronic waste that contains these elements and to assume their fate in the environment.
Abstract Calcite (CaCO3, trigonal crystal system, space group $$R\overline{3}c$$ R 3 ¯ c ) is a ubiquitous carbonate phase commonly found on the Earth’s crust that finds many useful applications in both scientific (mineralogy, petrology, geology) and technological fields (optics, sensors, materials technology) because of its peculiar anisotropic physical properties. Among them, photoelasticity, i.e., the variation of the optical properties of the mineral (including birefringence) with the applied stress, could find usefulness in determining the stress state of a rock sample containing calcite by employing simple optical measurements. However, the photoelastic tensor is not easily available from experiments, and affected by high uncertainties. Here we present a theoretical Density Functional Theory approach to obtain both elastic and photoelastic properties of calcite, considering realistic experimental conditions (298 K, 1 atm). The results were compared with those available in literature, further extending the knowledge of the photoelasticity of calcite, and clarifying an experimental discrepancy in the sign of the p 41 photoelastic tensor component measured in past investigations. The methods here described and applied to a well-known crystalline material can be used to obtain the photoelastic properties of other minerals and/or materials at desired pressure and temperature conditions.
Marian Rigñack-Delgado, Gerardo Orozco-Melgar, Harold Crespo-Sariol
et al.
En la presente investigación se utilizó la técnica de emisión acústica (EA) para el análisis de la porosidad de tobas vítreas y zeolitizadas de los yacimientos el Picao (TV-P) y Caimanes (TZ-C) respectivamente y de la manifestación de tobas de Baracoa (TV-B). Esta técnica sólo ha sido empleada en carbones activados. Las condiciones de experimentación para las tobas se determinaron mediante un diseño de experimento 23 con el programa estadístico Statgraphics Centurión XV: 10 ml de agua y 10 g de la muestra a 50 dB de ganancia. Se definieron las características porosas de los materiales estudiados por las técnicas clásicas (adsorción por N2 y CO2 y porosimetría de Hg), para luego comparar los resultados con la técnica de EA. Las adsorciones determinadas por N2 y por CO2, indicaron que la toba TV-P tiene mayor área superficial y mayor volumen de poros mientras que la toba TZ-C posee una alta micro porosidad con respecto a las otras muestras. La técnica de porosimetría de Hg demostró que las tobas vítreas tienen alto valor de porosidad y de volumen total de poros con valores de 49 % y 0,44 cm3/g respectivamente. Al comparar los resultados de la EA con las técnicas clásicas se estableció una mejor correlación con la técnica de adsorción por CO2, demostrándose que la EA es capaz de detectar la micro porosidad de un material.
Clécia Cristina Barbosa Guimarães, José Alexandre Melo Demattê, Antônio Carlos de Azevedo
et al.
ABSTRACT Weathering of the parent material is the initial process that plays an essential role in soil fertility. The study of this process has become crucial to better understand soil dynamics. Most studies on weathering are based on indexes that calculate the feldspar dissolution rate (for example, CIA, CIW, and PIA) which not always reflect the complexity in the soil profile. Other methodologies have been designed to improve these approaches, such as geochemical balance, difference of elemental contents (DE), and the W index. This work aim to assess the efficiency of these methods to identify variations in recent soil profiles developed from diabase as compared to the CIA, CIW, and PIA indexes. Data on the main oxides were used to calculate the geochemical balance, DE, CIA, CIW, PIA, and W indexes to analyze weathering intensity in two profiles originated from diabase in the São Paulo State, Brazil. The Ki and Kr indexes and Feo /Fed ratio were also factored and we analyzed the mineralogy of soil horizons and the source rock. The W index and DE presented greater weathering variation than the CIA, CIW, and PIA in both profiles. The geochemical balance, mineralogy, and the Ki, Kr and Feo /Fed ratios explained the variations between the horizons. The DE and geochemical balance together generated new information for the analysis of the weathering process than the isolated indexes.
Dust is one of the most common sources of air pollution in cities, providing a considerable health risk. Kandy, Sri Lanka, has been declared as a UNESCO World Heritage Site. As a result, a study into causes of air pollution in Kandy and its environs is urgently required. We examined at the composition of dust particles collected from the city and suburbs to determine the degree of particulate pollution. The abundance of particles and materials in various phases has previously been quantified in one dimension in an idealized sphere. The morphological examination of particulate matter is usually ignored. Eighteen road and thirteen household dust samples collected in the Kandy Municipal area were analyzed for elemental concentrations, as well as for mineralogical and morphological characteristics. Higher Ca, Zn, and Cu concentrations in the samples indicate anthropogenic (construction industry and traffic activities) influences on the dust. Mineralogically, fine and coarse dust fractions are dominated by clay minerals and quartz with feldspar. The majority of fibrous materials in dust are coated with secondary matter, resulting in short suspension duration in the atmosphere and, as a result, a reduction in the harmfulness of the fibers. In terms of mineralogy, morphology, and chemical properties, road and household dust samples are nearly identical. Despite the fact that dust is primarily derived from soil, its composition has been altered due to anthropogenic influences such as transportation and construction activities. As a result, dust containing clay particles can be regarded of as a fluxing and heavy metal accumulation medium. Although fibers have minor influence on human health and the environment, heavy metals have a significant impact. Though industrial and transportation activities in Kandy are remarkably low when compared to those in other major cities in Sri Lanka and megacities around the world, pollution levels in the city are comparably high. To reduce the vulnerability of the current pollution condition of the city, appropriate, long-term strategies for construction and transportation activities are required.
Abstract This article evaluates the efficiency, benefits and limitations of pre-concentration by density separation for process mineralogy studies of low-grade gold ore. The pre-concentration by density aims to generate a product with a high content of gold and to maximize the number of gold-bearing particles characterized, thereby increasing the representativity and reducing the number of polished sections to be analyzed. Pre-concentration by density was carried out for a low-grade sulfide gold ore (0.96 ppm) from the north of Brazil. The sample was ground to below 1.7 mm, sieved down to 0.037 mm and subjected to density separation, amalgamation of the heavy product and cyanide leaching of all products. Gold was assessed in each product to evaluate the separation recovery and distribution. The finer the particle size, the higher the gold distribution in the heavy product, due to a higher degree of liberation of gold and sulfides; these values varied from 65% to 84% in fractions below 0.60 mm and decreased from 40% to 13% in the coarser fractions. Regarding gold distribution, fractions finer than 0.84 mm indicates a notable increase on gold recovery by amalgamation, indication higher surface exposure.
The present article pays to some Alpine-Himalayan ophiolites of Late Cretaceous age from Darepahn area in the southern part of Nain-Baft Ophiolite belt. Whole rock processed data clearly shows that the metaperidotite rocks are silica-poor with low CaO, Al2O3, and TiO2 that reflect the predominance of olivine over calcic pyroxene in the protolithes. The considerable content of Co (85.6–124.6 ppm) and very low contents of Sc (4.3–15.3 ppm) and Sr (0.7-14 ppm) provided more evidence for olivine enrichment in the rock parentages. Calculating numbers of cation per formula unites based on EMPA results for distinguished Serpentine polymorphs (classified structurally via Raman spectroscopy) display that Tschermak substitution of trivalent cations for lizardite is tetrahedrally, and for chrysotile and antigorite, it is octahedrally. These chemical differentiations, lead to identifying chemical field plots in separator diagrams between SiO2, MgO, H2O, and Al2O3. Lizardite polymorphs can consider as primarily metasomatism results thru an iron-rich fluid occurrence. It has a considerable occupation of trivalent cations (especially Fe3+) and simultaneous less than 4 Si atoms in formula structure that reflected tetrahedral Tschermak substitutions. Antigorites have some deformed recrystallized textures along with high Σoct (Total Octahedral Cations) and low H2O content that could be considered as thermal originated polymorph. Chrysotiles have bimodal MgO and FeO contents that return to magnetite formations in groundmass and octahedral Tschermak substitutions on late-stage veins. The results exemplify compositional variations of Darepahn Serpentine polymorphs as a function of textural behaviors, structural position and thermodynamic condition of the formation process.
The two-stage 6-8 multi-anvil (MA8) apparatus is an important large-volume, high-pressure technique that has been widely used in the high pressure mineralogy and material synthesis, mainly at room temperature or above. Recently, we have successfully developed a two-stage MA8 apparatus for low-temperature physical property measurements. The first-stage anvils at top and bottom sides are fabricated as a single piece in order to reduce the total size of the cylindrical module, which is put in a top-loading high pressure cryostat and compressed by a 1000 ton hydraulic press. A castable, split octahedral gasket with integrated fin was specifically designed in order to introduce the electrical leads from the inside sample container filled with a liquid pressure transmitting medium. By using tungsten carbide (WC) second-stage cubes with a truncated edge length of 3 mm and an octahedral gasket with an edge length of 6 mm, we have successfully generated pressure over 20 GPa at room temperature. Since the high pressure limit can be pushed to nearly 100 GPa by using the sintered diamond second-stage cubes, our MA8 apparatus has a great potential to expand the current pressure capacity for precise low-temperature measurements with a large sample volume.
Edited by: A. Goñi, A. Cantarero, J. S. Reparaz