Mineral Phases Research Articles

Evaluation of the genotoxic and transformation potential induced by asbestos compared to cleavage fragments

The World Health Organization has confirmed that asbestos fibres are carcinogenic, claiming that asbestos-related diseases should be eradicated worldwide. Actinolite, amosite, anthophyllite, chrysotile, crocidolite, and tremolite are regulated asbestiform mineral phases. However, in nature, asbestos minerals occur either in a fibrous and asbestiform (original morphology characterized by high length-to-width ratio and provided of high tensile strength and flexibility) or fibrous but not asbestiform appearance. This study used human epithelial cancer cells (A549) and a mouse fibroblast cell line (Balb/c 3T3) to compare the genotoxic and carcinogenic effects of a sample of amphibole asbestos with samples of fibrous not asbestiform named cleavage fragments (CV) obtained by grinding non-asbestiform amphiboles. The results showed that exposure of alveolar lung cells to asbestos and elongated mineral particles, in the habit of cleavage fragments (CF) derived from the grinding of non-asbestiform amphiboles and serpentines, causes cytotoxic effects, oxidative stress and genotoxic damage. Moreover, CF obtained from an actinolite schist induces a transformation effect in the Balb/c 3T3 model. Together, these findings highlight the importance of considering CF as a potential threat to human health since it can cause genotoxic damage by triggering cellular transformation processes that overlap with the mechanisms involved in the carcinogenesis processes of asbestos.

Effect of Ultrafine Cement Mineral Phase C4AF on the Properties of PVDF Composite Films

ABSTRACTThe development of intelligent buildings requires energy harvesting technology, especially smart piezoelectric materials. This paper mainly explores the possibility of applying polyvinylidene fluoride (PVDF) as a piezoelectric energy storage material in building structures. In order to make PVDF piezoelectric energy storage materials suitable for the cement‐based materials, the cement mineral phase tetracalcium aluminate (C4AF) as filler and PVDF as matrix are used to prepare ultrafine C4AF‐PVDF composite films. The mechanical properties, crystal structure, thermal behavior, electrochemical behavior, and morphology of C4AF‐PVDF composite films are characterized. The results show that a small amount of C4AF can be uniformly dispersed in the PVDF matrix and fill the pores, which not only maintains the good toughness of the PVDF film but also promotes the nucleation and crystallization of the film. Meanwhile, the conceptual model developed in this paper shows the mechanism of C4AF on PVDF film in macro and microstructures, explains, and analyzes the influence of C4AF on the PVDF film matrix from the level of nucleation and crystallization. This paper can provide reference value for the application of cement‐based mineral phase materials combined with PVDF in the field of intelligent buildings for piezoelectric energy harvesting.

Limited reactivity of pyroxene and plagioclase in batch experiments with supercritical CO2 in the presence of NaCl and NaHCO3 in the context of CO2 sequestration via carbonation.

One-step high-pressure and high-temperature direct aqueous mineral carbonation of tailings derived from mining of Platinum Group Metals in South Africa requires a fundamental understanding of the reactivity of the most dominant mineral phases, i.e. pyroxene and plagioclase (66 wt. % and 12 wt. % of the bulk rock respectively) that are typically found in these tailings. The silicate minerals pyroxene and plagioclase were sampled from a pyroxenite footwall mined with the ore-bearing UG2 and from the Merensky Reefs outcropping in the eastern limb of the Bushveld Complex. These pyroxene and plagioclase grains were concentrated by gravity separation from the orthopyroxenite bulk rock and batch-reacted in a sodium chloride (NaCl) brine saturated with pure carbon dioxide (CO2) gas-only or seeded with sodium bicarbonate (NaHCO3; as an additional CO2 source) for 13days at 100°C and 10MPa. Pyroxene dissolved slightly but no weathering features were observed in plagioclase. Analyses of the filtrates obtained from the pyroxene sample in the absence of NaHCO3 showed an increased concentration of magnesium and calcium ions in the solution. However, they had also reached a cation saturation sealing. On the other hand, liquid samples from reactions where both CO2 gas and NaHCO3 were added to the solution exhibited a pronounced decrease in dissolved magnesium and calcium ions. XRD patterns of some of the post-reaction solids collected from the cation-depleted solution aliquots showed peaks of newly formed secondary magnesite and vermiculite. Moreover, the presence of magnesite was further confirmed by Raman shift analysis of the dried solid products. The formation of secondary magnesite was observed only in the experiments seeded with NaHCO3, specifically where the pre-reaction solid was pyroxene rich. Some of the resultant fluid chemistry was corroborated by the geochemical model that simulated the reaction parameters using the Geochemist Work Bench (GWB) software. Overall, the results indicate low pyroxene dissolution, which leads to limited carbonation. These findings suggest that the carbonation of PGM tailings may be constrained under the evaluated physicochemical conditions.

Microstructure and Wear and Corrosion Resistance of CoCrFeMoNiSix (x = 0.25, 0.50, 0.75) HEACs Prepared by Plasma Cladding

CoCrFeMoNiSix (x = 0.25, 0.50, 0.75) HEACs were successfully prepared on Q235 steel substrates by the plasma cladding method. The phase structure, microstructure, element distribution, and wear and corrosion resistance of these coatings were investigated by XRD, OM, SEM, EDS, a friction and wear tester, and an electrochemical workstation. The results show that the CoCrFeMoNiSix (x = 0.25, 0.50, 0.75) coatings are composed of a major FCC phase and minor BCC phase. With an increase in Si content, the lattice constant and cell volume of both phases and the BCC phase content in these alloys gradually increase, while the enthalpy of mixing, Gibbs free energy, atomic radius difference, VEC, and phase density decrease. All the three alloys exhibit typical dendritic structures. With an increase in Si content, the enrichment of Mo and Si in the interdendrite region is significantly reduced. The friction coefficients of CoCrFeMoNiSix (x = 0.25, 0.50, 0.75) HEACs show a trend of first increasing, then decreasing, and gradually stabilizing with an increase in time, and are 0.604, 0.526, and 0.534, respectively. The wear resistance of the three alloys is mainly related to the changes in crystallinity and high-strength BCC phase content caused by different Si contents. The polarization curves of CoCrFeMoNiSix (x = 0.25, 0.50, 0.75) high-entropy alloy coatings show an obvious passivation zone, and the corrosion resistance is significantly better than that of Q235 steel substrate. The CoCrFeMoNiSi0.75 coating has the highest self-corrosion potential, smallest self-corrosion current, largest capacitive reactance arc radius, and best corrosion resistance in a 3.5% NaCl solution.

Micro-computed tomography and laser micro-ablation on altered pyrite in lapis lazuli to enhance provenance investigation: a new methodology and its application to archaeological cases

This work presents an upgrade to the methodology adopted to investigate the provenance of the raw lapis lazuli material used in antiquity for carving precious artefacts. Samples from archaeological excavation contexts frequently display superficial degradation processes affecting the crystals of the mineral phases useful for provenance attribution (especially pyrite). To address this issue, an innovative workflow has been developed, centred on the application of X-ray micro-computed tomography (μ-CT) and micro-ablation treatments with a pulsed laser source prior to investigation with ion beam analysis (IBA). High-resolution μ-CT is employed to evaluate the alteration state of pyrite crystals within the entire volume of the lapis lazuli rock, and, if required, to identify the most suitable crystals on the surface for subsequent laser treatment. The micro-ablation procedure aims to create a small breach in the superficial altered layer (the irradiated areas are approximately 65 × 65 μm2), thereby exposing the preserved crystal beneath and allowing for the analysis of its trace element contents with IBA. The methodology of the workflow is presented, together with its first application to archaeological lapis lazuli material: three precious beads from the ancient Royal Cemetery of Ur (Mesopotamia, 3rd millennium BCE). The results are complemented by the application of a provenance protocol already validated that proved, for the first time using a micro-invasive analytical approach, a match between the Afghan quarry district and the raw material used to carve these beads.

Mechanical Properties and Durability Performance of Low Liquid Limit Soil Stabilized by Industrial Solid Waste.

To improve the mechanical and durability properties of low liquid limit soil, an eco-friendly, all-solid, waste-based stabilizer (GSCFC) was proposed using five different industrial solid wastes: ground granulated blast-furnace slag (GGBS), steel slag (SS), coal fly ash (CFA), flue-gas desulfurization (FGD) gypsum, and carbide slag (CS). The mechanical and durability performance of GSCFC-stabilized soil were evaluated using unconfined compressive strength (UCS), California bearing ratio (CBR), and freeze-thaw and wet-dry cycles. The Rietveld method was employed to analyze the mineral phases in the GSCFC-stabilized soil. The optimal composition of the GSCFC stabilizer was determined as 15% SS, 12% GGBS, 16% FGD gypsum, 36% CS, and 12% CFA. The GSCFC-stabilized soil exhibited higher CBR values, with results of 31.38%, 77.13%, and 94.58% for 30, 50, and 98 blows, respectively, compared to 27.23%, 68.34%, and 85.03% for OPC. Additionally, GSCFC-stabilized soil demonstrated superior durability under dry-wet and freeze-thaw cycles, maintaining a 50% higher UCS (1.5 MPa) and a 58.6% lower expansion rate (3.16%) after 15 dry-wet cycles and achieving a BDR of 86.86% after 5 freeze-thaw cycles, compared to 65% for OPC. Rietveld analysis showed increased hydration products (ettringite by 2.63 times, C-S-H by 2.51 times), significantly enhancing soil strength. These findings highlight the potential of GSCFC-stabilized soil for durable road sub-base applications. This research provides theoretical and technical support for the development of sustainable, cost-effective, and eco-friendly soil stabilizers as alternatives to traditional cement-based stabilizers while also promoting the synergistic utilization of multiple solid wastes.

Introducing the akrochordite mineral group, with the new mineral vargite from the Långban Mn-Fe deposit, Filipstad, Värmland, Sweden

ABSTRACT Vargite, ideally MnCu2Mn2(OH)4(H2O)4(AsO4)2 – named after the Swedish miner Erik Gustaf Varg (1886–1970), who collected the type specimen – was found in the Långban Fe-Mn deposit. It occurs in open cavities in a brecciated and later hydrothermally leached carbonate groundmass, in association with hausmannite, calcite, rhodochrosite, baryte, a serpentine-group mineral, and galena. Additional minor phases are hedyphane, phlogopite and yarrowite. Paragenetically, it is a late-stage mineral, formed as a result of the interaction between an As-rich hydrothermal fluid and Mn-oxide(s) and Cu-sulphide, under low P- and T-conditions. Vargite forms bright green, semi-spherical aggregates up to 0.5 mm across, consisting of numerous thin, lath-shaped crystals, elongated along [100] and with a maximum length of 200 µm. Mohs hardness is ≈ 3 and D calc = 3.49(1) g·cm−3. The empirical chemical formula obtained from electron probe micro-analyses analyses and based on 16 anions is (Cu1.77Mg0.33)Σ2.10(Mn2.94Ca0.04Pb0.01)Σ2.99(As1.95Si0.02)Σ1.97O8(OH)4.03·3.98H2O. The crystal structures of vargite and the isotypic mineral akrochordite [MnMn2Mn2(OH)4(H2O)4(AsO4)2] have been refined in the space group P21/c from single-crystal X-ray diffraction data to R1 = 3.07% and 2.46%, respectively, giving the following sets of unit-cell parameters: a = 5.6251(14), 5.6832(11) Å, b = 17.452(5), 17.631(5) Å, c = 6.905(2), 6.8417(19) Å, β = 100.21(5)°, 99.51(4)°, and V = 667.2(3), 676.1(3) Å3, with Z = 2. A Raman spectrum of vargite, with major bands at 3510, 1610, 850, 780, 476, 428, 389, and 308 cm−1, strongly resembles that of isotypic guanacoite, [MgCu2Mg2(OH)4(H2O)4(AsO4)2]. Vargite, akrochordite, and guanacoite constitute the newly established akrochordite group.

Porosity and mineralogy in the Lajas tight gas sandstone reservoir, Neuquén Basin, Argentina

ABSTRACT In specific subsurface conditions, the sandstones of the Lajas Formation represent a tight gas reservoir in a deltaic mouth-bar system. Therefore, understanding the diagenetic processes that affected these sandstones is a first step towards reservoir quality prediction and production optimization.14C-PMMA autoradiography can be used to characterize the porosity distribution at centimeter-to-micrometer scales. The mineral phases can be associated with specific porosities using scanning electron microscopy (SEM) in the backscattered-electron imaging mode (BSEi) and can be combined with elemental mapping using energy-dispersive X-ray spectroscopic (EDS) analysis. For bulk analysis, porosity mapping is useful for characterizing the constrictivity and the tortuosity of the porous network created by the geological processes related to the basin’s evolution (e.g., compaction, dissolution, fracturing, cataclasis). 14C-PMMA autoradiography offers a reliable porosimetry method which is adaptable to most rocks. In our study, the superimposition of porosity maps and mineral maps revealed that: 1) secondary porosity, deriving from feldspar dissolution in medium- to coarse-grained sandstone, and the varying degree of dissolution are both influenced by grain size and degree of cementation, 2) mudstone rip-up clasts have homogeneous porosities (3–4%), 3) the host rock’s porosity varies widely (1–8%), 4) bioturbated siltstone and sandstone present higher porosities within the trace fossils, mainly associated with organo-pores (primary porosity in the organic matter), mineral formation (pyrite precipitation), and clay development (microporosity). Integrating these petrophysical and mineralogical observations with the interpretation of the sedimentary and structural processes that affected the lithologies analyzed allows the following generalizations: 1) the highest porosity and permeability occur in samples representing high-energy environments of deposition (deltaic channel infills and mouth bars), 2) deformation bands cannot be considered fairways for fluid migration, as they have a lower porosity than the sandstone matrix, mainly because dilational shear bands underwent cementation and compactional shear bands underwent cataclasis.

Catalysis in Frequency Space: Resolving Hidden Oscillating Minority Phases and Their Catalytic Properties

Catalysis in Frequency Space: Resolving Hidden Oscillating Minority Phases and Their Catalytic Properties

Bifunctional NiCo-CuO Nanostructures: A Promising Catalyst for Energy Conversion and Storage.

This investigation explores the potential of co-incorporating nickel (Ni) and cobalt (Co)into copper oxide (CuO)nanostructures for bifunctional electrochemical charge storage and oxygen evolution reactions (OER). A facile wet chemical synthesis method is employed to co-incorporate Ni and Co into CuO, yielding diverse nanostructured morphologies, including rods, spheres, and flake. The X-ray diffraction (XRD) and Raman analyses confirmed the formation of NiCo-CuO nanostructure, with minor phases of nickel oxide (NiO)and cobalt tetraoxide (Co3O4). High-resolution Transmission Electron Microscope (HRTEM) also confirms the diverse morphologies and the minor phases of oxides. Synchrotron X-ray absorption spectroscopy revealed higher charge states of Cu, Ni, and Co in the NiCo-CuO nanostructure, enhancing its charge storage and OER. Site-selective X-ray absorption near edge structure analysis elucidated the spatial distribution of Cu, Ni, and Co in the nanostructure. Furthermore, extended X-ray absorption fine structure spectroscopy provided insights into the local atomic structures, revealing increased coordination numbers and interatomic distances in the NiCo-CuO nanostructure. In situ Raman analysis discloses the transformation of Co3O4 into cobalt hydroxide (Co(OH)2) and cobalt oxide (CoO) into cobalt oxyhydroxide (CoOOH) The NiCo-CuO nanostructures exhibited superior specific capacitance, favorable Tafel behavior, and low overpotential positioning as promising bifunctional materials for energy storage and conversion applications. This work contributes to the development of efficient CuO nanocatalysts.

Coal ash induced ring formation for magnesian flux pellets production process and regulating control measures

The forming of rings was a bottleneck of magnesian flux pellets in a rotary kiln, which limited production efficiency. This paper analyses how the coal ash content affects bonding strength and melting behaviour by using magnesian flux pellet powder and coal ash. Also, the mineral phase, microstructure and liquid phase composition of pellet powders that have different coal ash content are analysed in a study. The results show that when the ash content is less than 0.5%, the ash has little influence on the ring-forming material, but when the ash content is more than 0.5%, the ash significantly strengthens the bonding process of the pellet powder. That is, the ash content should not exceed 0.5%. In addition, the consolidation mechanism of the magnesium fluxes spherical ring is mainly solid-phase consolidation. Anorthite and mullite are formed in magnesian flux pellet powders when coal ash is added, resulting in a change in mineral composition. It is worth noting that anorthite exhibits high reactivity with other mineral phases, leading to eutectic reactions. When more coal ash is added, the chemical composition of the mineral phase changes in the briquettes, and the liquid phase exhibits gradual increments in SiO2, MgO and Al2O3 content. According to the phase diagram of Fe2O3-CaO-SiO2-3wt%MgO-6wt%Al2O3, the position of the silicate mineral phase shifts towards the high SiO2 region, which has the lower temperature. The liquid phase ratio of the briquette increases in this region, ultimately resulting in the formation of rings in the rotary kiln.

Mineral forms of phosphorus in ooidal iron ores of the Marsyaty deposit (Northern Urals)

Horizons enriched in phosphorus are identifed in ooidal ironstones underlying the oxide-carbonate manganese ores of the Marsyaty deposit (Northern Urals). The maximum P2O5 content reaches 6.37 wt. % in a quartz sandstone interbed with ooids consisting of Fe3+ oxyhydroxides and is associated with authigenic fuorapatite. In iron oxyhydroxide ooidal ores, phosphorus is present mainly as apatite, which forms massive and radial zones in both the ooids and the matrix. In siderite ooidal ores, the phosphate minerals include apatite and hydrous Al and Ca silicate-phosphates, possibly a mineral of the crandallite-goyazite series and perhamite. They occur as radial aggregates emphasizing the zonation of carbonate ooids and common in the matrix. Phosphorus is also part of an authigenic rhabdophane-like mineral flling the radial and concentric cracks in iron oxyhydroxide ooids. Some phosphorus is associated with detrital monazite and apatite. Phosphorus for the formation of phosphates was most likely sourced from organic relics, whereas seawater and minerals unstable under sedimentation and diagenesis conditions were the source of cations. The formation of crystalline phosphates is associated with diagenetic processes, during which the organic relics were fermented and replaced by mineral phases, while the minerals metastable in shallow marine basin were decomposed with desorption of elements captured by Fe3+oxyhydroxides from seawater.

Indium Doping Effects on the Structural, Morphological and Electrical Properties of WO3 Powder Pellets

Abstract Tungsten oxide powders were doped with indium at weight percentages ranging from 5 to 15 wt.% and pressed into pellet form under a pressure of 200 bars. The doping process was carried out using the solid-state reaction technique. The doped samples were sintered at 750 °C for 12 hours. Both undoped and indium-doped powder pellets exhibited a triclinic structure, with hexagonal InxWO3 emerging as a minor phase that increased with higher indium content. Indium doping increased microstrain, the percentage of stacking faults, and defect concentration while decreasing the crystallite sizes in the WO3 powder pellets. Morphological analysis of the samples revealed irregular grain shapes and sizes within the pellets. Notably, indium doping significantly reduced the porosity of WO3 from 7.42% to 3.83% as the indium content increased to 15 wt.%. Electrically, the n-type resistivity increased with higher doping levels, indicating deeper donor levels. Specifically, the donor states in the powder pellets increased from 0.21 eV to 0.27 eV as the indium content rose from 5 wt.% to 10 wt.%, and further reached 0.29 eV at 15 wt.% indium. Moreover, AC signal analysis of the powder pellets demonstrated their potential as microwave resonators suitable for antenna applications. Indium doping effectively engineered the maximum cutoff frequency, with values reaching 80 GHz in WO3 pellets doped with 15 wt.% indium. These powder pellets, with thicknesses not exceeding 700 μm and electrode areas of 3.14×10⁻² cm², show great promise for 5G/6G technology applications as concurrent quad-band antennas.

Sol-Gel Synthesis of TiO2 from TiOSO4 (Part 2): Kinetics and Photocatalytic Efficiency of Methylene Blue Degradation Under UV Irradiation

The sol-gel process was used to create titanium dioxide (TiO2) nanoparticles, a nanocrystalline semiconductor. How several synthesis factors, such as titanium precursor concentration, annealing temperature, and peptization temperature, affected the structural and morphological properties of TiO2 nanoparticles were thoroughly explored. X-ray diffraction (XRD), infrared spectroscopy (IR), scanning electron microscopy (SEM), measurements of the specific surface area and pore size using the BET method, and UV-visible diffuse reflectance spectroscopy were all used in this investigation. The specific surface area determined by BET analysis decreased with increasing calcination temperature. The XRD analysis showed that a composite sample consisting mainly of anatase with minor brookite phases was obtained when the titanium precursor concentration ranged between 0.2 and 0.4 M, whereas a concentration of 0.5 M resulted in the formation of pure anatase. The photocatalytic activity of the synthesized TiO2 powders under different operational parameters was evaluated for the common commercial textile dye, i.e., methylene blue (MB). It was experimented that the model pollutant decoloration follows the Langmuir–Hinshelwood (L-H) model. In view of this detailed research work, it was observed that the TiO2 produced with a titanium precursor concentration of 0.3 M, a pH value of 5 during the peptization step, and an annealing temperature of 600 °C were found to be the best conditions for this catalytic degradation process. When used in conjunction with a TiO2 concentration of 0.04 g/L and a reactor suspension pH value of 6.0, the TiO2 catalyst produced a stunning 98% degradation of methylene blue under these circumstances.

Pseudomorphic Transformation in Nanostructured Thiophene-Based Materials.

This study reveals the capability of nanostructured organic materials to undergo pseudomorphic transformations, a ubiquitous phenomenon occurring in the mineral kingdom that involves the replacement of a mineral phase with a new one while retaining the original shape and volume. Specifically, it is demonstrated that the postoxidation process induced by HOF·CH3CN on preformed thiophene-based 1D nanostructures preserves their macro/microscopic morphology while remarkably altering their electro-optical properties by forming a new oxygenated phase. Experimental evidence proves that this transformation proceeds via an interface-coupled dissolution-precipitation mechanism, leading to the growth of a porous oxidized shell that varies in thickness with exposure time, enveloping the pristine smooth core. The oxygenated species exhibits stronger electron-acceptor characteristics than the core material, promoting charge transfer state formation, as confirmed by microspectroscopy and DFT calculations. This enables (i) precise modulation of the nanostructure's surface potential, allowing for the formation of entirely organic heterojunctions with precise spatial resolution via wet chemical processing; (ii) effective doping of the nanostructure, resulting in a strong change of the conductivity temperature dependence and a switch between a low and high conduction state depending on the applied bias. Overall, this work showcases an approach to engineering "impossible" composite architectures with pre-established morphology and tailored chemical-physical properties.

Geochemical and mineralogical differences between supergene and hypogene gold mineralization and influence on gold recovery: A case study of the Faina gold deposit, Pitangui greenstone belt, Brazil

The Faina gold deposit, located in the Pitangui Greenstone Belt, NW of the Quadrilátero Ferrífero, Brazil, has produced gold from the oxidized portion of the deposit between June 2010 and June 2013. However, the deeper hypogene (sulfide-rich) section of the deposit has shown lower-than-expected recovery rates after direct leaching, leading to the interruption of gold production. This research presents a multi-methodological approach (drill core description, multi-element geochemical analyses and mineral characterization using microscopy and X-ray diffraction) to investigate describe the Faina gold deposit and identify the cause of low recoveries from the hypogene zone. The stratigraphy at Faina consists of a sequence of meta-mafic and meta-sedimentary rocks, with a thick (>40m) saprolite horizon (oxidized portion). Both the meta-mafic rocks and saprolite host gold mineralization, which is identified by distinct geochemical and mineral signatures: 1) Au-As-W in the hypogene zone, with gold associated with sulfides or as disseminations in silicates and 2) Au-As-W in the oxide-rich shallower section with free-milling gold associated with quartz, iron oxide-hydroxides and clay minerals. Geochemical, mineral and textural relationships in the hypogene zone show that submicroscopic gold particles associated with minerals, that consume leaching solution minerals (arsenopyrite, pyrrhotite and berthierite) may cause refractoriness during direct leaching. Separation of gold from these mineral phases, in addition to concentration methods during ore processing may increase gold recovery. The results presented in this research emphasize the importance of a detailed geochemical and mineral characterization to reveal the contrasting mineral and chemical compositions between hypogene and oxidized zone, which may influence gold recovery.

Effect of O2/CO2 atmosphere on the mineral phase composition of cement clinker

Effect of O2/CO2 atmosphere on the mineral phase composition of cement clinker

Mechanism of mineral phase transformation in preparing aluminum alloy by electrolysis of molten salt from aluminum alloy dross

Mechanism of mineral phase transformation in preparing aluminum alloy by electrolysis of molten salt from aluminum alloy dross

Pilot-scale recovery of iron from refractory specularite ore using hydrogen-based mineral phase transformation technology: process optimization, mineral characterization, and green production

Pilot-scale recovery of iron from refractory specularite ore using hydrogen-based mineral phase transformation technology: process optimization, mineral characterization, and green production

Morphological Observation and Mineralogical Analysis of Basaltic Debris from a Chang'e 5 Drilled Sample

This paper analyzes the morphological characteristics and mineralogy of drilled basaltic clast sample CE5Z0806YJYX004, compares the variations in Chang'e-5 samples at different depths, and conducts a comparative analysis with surface-collected samples from Chang'e-5 and Apollo missions. Interestingly, Advanced electron microscopy identified bubbles and microcracks on the surface of some constituting mineral particles, and also displays crystalline particles with distinct rock textures and spherical droplets, revealing surface phenomena formed by space weathering. Based on Raman spectroscopy analysis, the main mineral phases were identified as 49.6 vol% pyroxene, 31.4 vol% plagioclase and 8.8 vol% olivine. Apatite, ilmenite and cristobalite are also found. The results indicate that the Chang’e-5 lunar soil exhibits similar mineral compositions at different depths. In short, a comparison was made between our drilling sample and the Chang'e 5 soil samples as well as samples from the Apollo mission series, demonstrating the physical similarities and some variations.