Applied Clay Science最新文献

{"title":"Dispersing sepiolite crystal bundles into nanofibers under expansion effect via steam pressure change and vacuum freeze-drying processes","authors":"Wenjia Yang ,&nbsp;Youhang Zhou ,&nbsp;Tianyu Gong ,&nbsp;Qiaolong Zhang","doi":"10.1016/j.clay.2025.107779","DOIUrl":"10.1016/j.clay.2025.107779","url":null,"abstract":"<div><div>Sepiolite nanofibers mainly exist in the form of crystal bundles, and the crystal bundles often bond with each other to form aggregates, which makes it difficult to effectively display its nanometer characteristics. Based on the excellent water absorption characteristics of sepiolite, a new approach for dispersing the aggregates and crystal bundles into nanofibers was developed via steam pressure change and vacuum freeze-drying processes. The dispersion effect was evaluated using laser particle size analyzer, XRD, FTIR, SEM, TEM, and surface area porosity analyzer. The experiments found that finite times repeated using steam pressure change process improved the crystal bundles dispersion effect. Adding vacuum freeze-drying process further promoted the crystal bundles dispersion. The dispersion effect of the sample after two times of steam pressure change and one time of vacuum freeze-drying processes was optimal. Compared with the original sample, particle size corresponding to a cumulative volume percentage of 50 % and 90 % (D50 and D90) of the treated sample reduced by 84 % and 91 %, respectively. The crystal bundles with a width of 0–120 nm accounted for more than 90 %. The specific surface area (<em>S</em>_BET) increased by 62 %, reaching up to 237 m²g⁻¹, and the rotary viscosity increased from 584 mPa·s of original sample to 1635 mPa·s. The experimental results validated that the expansion effect of steam pressure change and vacuum freeze-drying processes can effectively achieve the non-destructive dispersion of sepiolite crystal bundles. The proposed method may provide a new idea for high value industrial production of fibrous clay.</div></div>","PeriodicalId":245,"journal":{"name":"Applied Clay Science","volume":"270 ","pages":"Article 107779"},"PeriodicalIF":5.3,"publicationDate":"2025-03-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143579264","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Influence of bentonite on flotation of minerals with different densities","authors":"Nadia Kashif,&nbsp;Boris Albijanic,&nbsp;Jing Jing Xu,&nbsp;Teresa McGrath,&nbsp;Muhammad Kashif Nazir,&nbsp;Michael Hitch,&nbsp;Bogale Tadesse","doi":"10.1016/j.clay.2025.107778","DOIUrl":"10.1016/j.clay.2025.107778","url":null,"abstract":"<div><div>This short communication investigates the impact of bentonite on the flotation performance of minerals with varying densities, specifically galena and sphalerite. Despite existing research on bentonite influence on flotation, its effects on minerals with different densities have not been analyzed so far. The results from this study demonstrated that bentonite adversely affected the flotation recoveries of both galena and sphalerite due to the high pulp viscosity. The addition of Ca²⁺ ions mitigated this detrimental effect by reducing the pulp viscosities around 8 times. As a result, the flotation performance of galena was markedly enhanced, showing a 33 % increase in recovery and a 37 % improvement in settling rates. However, in the absence of Ca²⁺ ions, the flotation recovery of galena decreased more than that of sphalerite, considering that the density of galena is 1.9 times higher than that of sphalerite. This study shows that in the presence of Ca²⁺ ions, the flotation recoveries of galena and sphalerite became similar, as Ca²⁺ reduced the consistency index and prevented galena particles from detaching from bubbles.</div></div>","PeriodicalId":245,"journal":{"name":"Applied Clay Science","volume":"270 ","pages":"Article 107778"},"PeriodicalIF":5.3,"publicationDate":"2025-03-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143579265","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The effect of wollastonite on sintering of anorthite ceramic body based on illite-smectite clay and kaolin","authors":"Radomir Sokolar ,&nbsp;Martin Nguyen ,&nbsp;Dalibor Vsiansky ,&nbsp;Oldrich Pavelka ,&nbsp;Anton Trník","doi":"10.1016/j.clay.2025.107774","DOIUrl":"10.1016/j.clay.2025.107774","url":null,"abstract":"<div><div>The effect of different character of plastic raw materials based on different clay minerals (kaolin vs. I/S clay based on interstratified illite/smectite clay minerals) and different source of wollastonite (bludovite rock vs. natural wollastonite) on the sintering process of anorthite porcelain body is studied. The sintering temperature according to vacuum water absorption is defined for samples containing 40 % of wollastonite raw material in the range of firing temperatures from 850 °C to 1200 °C. The mineralogical composition of fired samples was observed from the firing temperature of 850 °C up to the sintering temperature. The sintering temperature of all studied samples is lower than 1200 °C. The lowest value is obtained by the combination of illite/smectite clay and natural wollastonite (1115 °C). The type of used plastic raw material also significantly affected the mechanism of anorthite formation during firing. The highest content of anorthite (over 90 %) in the crystalline phase of the sintered body is observed in kaolin-based samples. Primary mullite is identified in small amounts and transiently only in kaolin-based samples after a firing at 950 °C and 1050 °C, and then participates in the formation of anorthite. Diopside was detected in sintered samples based on bludovite rock as a rest from wollastonite raw material.</div></div>","PeriodicalId":245,"journal":{"name":"Applied Clay Science","volume":"270 ","pages":"Article 107774"},"PeriodicalIF":5.3,"publicationDate":"2025-03-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143550060","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Dehydroxylation kinetics of kaolinite and montmorillonite examined using isoconversional methods","authors":"Oluwadamilare Charles Adesina ,&nbsp;Sayee Srikarah Volaity ,&nbsp;Bryan K. Aylas-Paredes ,&nbsp;Chengqing Qi ,&nbsp;Aditya Kumar ,&nbsp;Narayanan Neithalath","doi":"10.1016/j.clay.2025.107776","DOIUrl":"10.1016/j.clay.2025.107776","url":null,"abstract":"<div><div>The use of calcined clays as supplementary cementitious materials (SCMs) in concrete is a promising strategy towards decarbonizing the cement and concrete industry. This is especially relevant considering the ever-increasing demand for concrete. Comprehensive understanding of the kinetics of calcination is essential towards maximizing the potential reactivity of clay minerals while ensuring energy efficiency. In this study, the kinetics of the dehydroxylation of kaolinite and montmorillonite are investigated under non-isothermal conditions at constant heating rate. Activation energies (<span><math><msub><mi>E</mi><mi>a</mi></msub></math></span>) are determined via Friedman differential and advanced Vyazovkin incremental methods over the isoconversional range; these are devoid of computational approximations, thus allowing kinetic analysis without assuming a specific reaction model. Kinetic equations—in the differential form as well as a combination of differential and integral forms are compared against the experimentally determined reaction models to identify the most probable dehydroxylation mechanism for kaolinite and montmorillonite. A reaction order mechanism is established for dehydroxylation of kaolinite, while montmorillonite is noted to undergo dehydroxylation via a single-step reversible diffusion-controlled process. Kinetic triplet—comprising activation energy, reaction model and pre-exponential factor—is used to predict isothermal calcination conditions, which is further verified using analytical techniques. Heat release rates of clay-portlandite blends from isothermal calorimetry are used within a thermodynamic framework to quantify reactivity of the calcined clays. The study demonstrates a general approach based on isoconversional methods to predict calcination conditions for different clays that can be used in efficient and optimized production of blended cements or SCMs.</div></div>","PeriodicalId":245,"journal":{"name":"Applied Clay Science","volume":"270 ","pages":"Article 107776"},"PeriodicalIF":5.3,"publicationDate":"2025-03-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143550061","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Self-assembly of halloysite nanotubes in water modulated via heterogeneous surface charge and transparent exopolymer particles","authors":"Ilnur Ishmukhametov ,&nbsp;Svetlana Batasheva ,&nbsp;Svetlana Konnova ,&nbsp;Yuri Lvov ,&nbsp;Rawil Fakhrullin","doi":"10.1016/j.clay.2025.107775","DOIUrl":"10.1016/j.clay.2025.107775","url":null,"abstract":"<div><div>Halloysite clay nanotubes are a viable model to investigate the colloid behaviour of particles dispersed in water. They demonstrate excellent colloid stability in water due to the strong overall negative surface charge. We performed detailed characterisation of halloysite surface inhomogeneity and in situ observations of diluted halloysite water dispersions behaviour. Using dark-field microscopy, we detected an aggregation between individual halloysite rods, behaving unlike the bulk majority of the non-aggregating nanoparticles. The stochastic distribution of positively-charged patches on overall smooth halloysite surfaces facilitates the electrostatic clustering of individual clay nanotubes into stable aggregates having end-to-end and end-to-side configurations. Another pattern of halloysite aggregation through seemingly long-range attraction of like-charged colloids was attributed to trace amounts of transparent exopolymer particles (TEP), ubiquitous biogenic microgels, persisting in deionised water and bridging individual halloysites into long-standing coordinated clusters. These aggregates demonstrate the earlier unknown role of water-suspended nanoscale particulate organic matter in counterintuitive long-range aggregation of like-charged colloids. We also found that microbial biopolymer mucospheres attract halloysite rods, forming unusual sea urchin-like motile microstructures, confirming the participation of TEP in natural colloids self-assembly. The persistence of barely detectable amounts of TEP in sterile purified deionised water suggests their important role in nano/micro scale processes.</div></div>","PeriodicalId":245,"journal":{"name":"Applied Clay Science","volume":"270 ","pages":"Article 107775"},"PeriodicalIF":5.3,"publicationDate":"2025-03-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143550059","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The reversibility of interlayer ion fixation in the smectite of BCV 2017 bentonite during long-term heating in air at 200 °C, a detailed mineralogical study","authors":"Magdaléna Koubová ,&nbsp;František Laufek ,&nbsp;Irena Hanusová ,&nbsp;Marek Szczerba","doi":"10.1016/j.clay.2025.107773","DOIUrl":"10.1016/j.clay.2025.107773","url":null,"abstract":"<div><div>In the context of studies related to the disposal of heat-generating wastes, the aim of this study was to characterize the mineralogical transformations that take place in the BCV 2017 Ca-Mg bentonite (Černý vrch bentonite, Czech Republic) following short (1-day) and long-term (47-month) heating in air at 200 °C. A laboratory procedure involving interlayer cation exchange using the Cu-trien complex with subsequent ethylene glycol solvation and full-profile diffraction pattern modelling was successfully applied for the comparison of the original bentonite and the material heated at 200 °C in air, as well as their subsequent rehydration.</div><div>In the original bentonite, two smectite-rich mixed layers minerals were modelled, consisting of 10-Å, high- and low-charge smectite layers. The 10-Å layers represented both the illite and also smectite layers with fixed Mg²⁺ and Ca²⁺ ions in the interlayer. After heating at 200 °C for 47 months, the total cation exchange capacity (CEC) decreased from 58 to 48 meq/100 g, the content of exchangeable Ca²⁺ increased from 25 to 27 meq/100 g, and the content of exchangeable Mg²⁺ decreased from 47 to 27 meq/100 g. The increase of exchangeable Ca²⁺ was caused by liberation of originally fixed Ca²⁺ in the interlayer of smectite while decrease of exchangeable Mg²⁺ was due to its fixation. The predominance of the fixation of interlayered Mg²⁺ over the liberation of Ca²⁺ led to the observed decrease of CEC. This decrease was accompanied by increase in the number of both smectite layers with interlayer-fixed Mg²⁺ (10-Å layers) from 12 to 19 % (an average value of two smectite-rich MLMs), and low-charged smectite layers from 67 to 76 % in MLMs. A simultaneous decrease in the number of high-charged smectite layers from 22 to 5 % was observed. The BCV 2017 bentonite heated for 1-day reached intermediate values between the original and 47-month heated bentonites.</div><div>The fixation of the interlayered Mg²⁺ was partially reversible, increasing from 27 to 31 meq/100 g after rehydration for 54 days under relative humidity of 97.6 %. The percentage of the 10-Å layers decreased from 19 to 16 % of MLMs and the CEC increased from 48 to 52 meq/100 g. Similar results were obtained when the heated bentonite was saturated with liquid water with 1:100 solid:liquid ratio for the same time period.</div></div>","PeriodicalId":245,"journal":{"name":"Applied Clay Science","volume":"270 ","pages":"Article 107773"},"PeriodicalIF":5.3,"publicationDate":"2025-03-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143529822","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Assessment of Tunisian clays for their potential application as excipient in pharmaceutical preparations: 2-amino-5-chlorobenzophenone adsorption","authors":"Safa Gamoudi ,&nbsp;Jihene Manai ,&nbsp;Wilfried G. Kanhounnon ,&nbsp;Didilia Ileana Mendoza-Castillo ,&nbsp;Adrián Bonilla-Petriciolet ,&nbsp;Yann Foucaud ,&nbsp;George E. Christidis ,&nbsp;Ezzeddine Srasra ,&nbsp;Michael Badawi","doi":"10.1016/j.clay.2025.107760","DOIUrl":"10.1016/j.clay.2025.107760","url":null,"abstract":"<div><div>The objective of this manuscript was to test the drug-loading and delivery properties of Tunisian clays to demonstrate their potential as low-cost excipients in pharmaceutical formulations. Raw kaolinite, purified smectite, and organophilic smectite were studied for the adsorption and desorption of 2-amino-5-chlorobenzophenone (2A-5BC) as a drug model molecule. The adsorption and desorption properties of these clay samples were investigated under different pH conditions, including those emulating the intestinal and gastric fluids from human body. DFT calculations were performed to characterize the atomic interactions involved in the adsorption mechanism. The adsorption and desorption properties of these clays were correlated with their main physicochemical properties and textural parameters. The maximum 2A-5BC adsorption (<em>i.e.</em>, 48.2 mg/g) was achieved using smectite functionalized with HDTMA. Electrostatic forces and hydrogen bonds played a relevant role during 2A-5BC adsorption. The desorption of 2A-5BC from clay samples was effective at 37 °C and pH similar to the intestinal and gastric fluids, thus reaching desorption efficiencies of up to 93 %. 2A-5BC desorption data were modeled with the Korsmeyer-Peppas equation and the results indicated the presence of a non-Fickian mass transport. Tunisian smectite functionalized with HDTMA presented promising performance and can be considered as a potential excipient in pharmaceutical formulations.</div></div>","PeriodicalId":245,"journal":{"name":"Applied Clay Science","volume":"269 ","pages":"Article 107760"},"PeriodicalIF":5.3,"publicationDate":"2025-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143519600","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Electrochemically-deposited NiAl-layered double hydroxide/Ni electrocatalysts for enhanced magnetic water oxidation","authors":"Leila Jafari Foruzin ,&nbsp;Farzad Nasirpouri ,&nbsp;Hongxing Dai","doi":"10.1016/j.clay.2025.107770","DOIUrl":"10.1016/j.clay.2025.107770","url":null,"abstract":"<div><div>The water oxidation is a promising method for generating the renewable energy. However, the high catalytic performance using stable electrocatalysts in alkali solutions remains limited. In this work, we herein report a facile method of deposition of NiAl-LDH electrocatalyst that addresses the above challenge under a magnetic field. Water oxidation behavior of the new electrodeposited nickel‑aluminum layered double hydroxides (NiAl-LDH) on Ni electroplated on the Cu substrate and their remarkable improvements in electrocatalytic activity under the external magnetic fields in alkali solutions were studied. Ni films were first electroplated on the Cu substrate using the direct current (DC) method. NiAl-LDH was coated on the Ni/Cu substrates using the electrochemical deposition method, and their water oxidation performance was investigated in the KOH aqueous solution (0.1 mol⋅L⁻¹) at 25 °C in the absence and presence of magnetic field. It was found that the oxygen evolution reaction (OER) over NiAl-LDH/Ni/Cu was improved when water oxidation was conducted under a magnetic field (<em>μ</em>_oH_┴ = 0.2 T) by decreasing the onset potential, Tafel slope, and overpotential or by increasing the current density (about 54 mA⋅cm⁻²). The effects were even more pronounced when the magnetic field was applied perpendicular to the electrode plane, reaching the OER overpotential of about 310 mV and the Tafel slop of about 142 mV⋅dec⁻¹. We interpreted the effect of magnetic water electrolysis by the ordinary magnetohydrodynamics (MHD) which enhanced the mass transport, increased the limiting current density, and removed the blocking oxygen gas bubbles accumulated on the electrode surface. The present investigation provides a low-cost electrocatalyst system for efficient electrochemical water oxidation.</div></div>","PeriodicalId":245,"journal":{"name":"Applied Clay Science","volume":"269 ","pages":"Article 107770"},"PeriodicalIF":5.3,"publicationDate":"2025-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143527124","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Structure–property correlations for PEG-interpenetrated hybrids of poly(acrylamide-co‑sodium acrylate) reinforced with Laponite, halloysite, sepiolite and montmorillonite","authors":"Rabia Bozbay ,&nbsp;Mertcan Er ,&nbsp;Kübra Kara Ersoy ,&nbsp;Nermin Orakdogen","doi":"10.1016/j.clay.2025.107763","DOIUrl":"10.1016/j.clay.2025.107763","url":null,"abstract":"<div><div>This study investigates the impact of different clay types on the properties of clay polymer nanocomposites (CPNs). semi-interpenetrated (semi-IPN) cryogels consisting of poly(acrylamide-co‑sodium acrylate)/poly(ethylene glycol) (PAN/PEG) and various clay minerals such as Laponite, sepiolite, halloysite, and montmorillonite were prepared following “in situ” synthetic protocol. The aim was to determine most effective inorganic component for developing desired elasticity and swelling/shrinking ability. By fixing the concentration of clay minerals embedded in CPNs as 1.50 % (<em>w</em>/<em>v</em>), the effect of inorganic clay type on structural properties was evaluated in terms of polymerization temperature, compressive elasticity, pH and thermo-sensitivity. Clay type had an effect on the thermal stability of semi-IPNs, while sepiolite increased the stability and compressive modulus to a higher extent. Among the four types of semi-IPNs, the water absorbency of montmorillonite-integrated gel was the highest, while that of sepiolite-doped was the lowest. The elastic moduli of semi-IPNs incorporated with same amount of clay is in the order Sepiolite &gt; Halloysite &gt; Laponite &gt; Montmorillonite. Changing pH in the range of 2.1 to 11.2 significantly increased the swelling, while a small variation in pH 6.6 caused a large difference in swelling capacity. For pH-dependent cyclic swelling, the highest swelling-shrinkage response was observed in Laponite-doped cryogels. The swelling of nanocomposites was significantly weakened by the change in ionic strength, while the swelling increased with the incubation temperature, showing good agreement with Fickian diffusion. Among the nanocomposites for cationic methylene blue (MB) dye, Laponite-integrated semi-IPNs exhibited the highest adsorption capacity from aqueous solution with 89.51 mg/g. MB adsorption kinetics followed pseudo-second-order, Freundlich and Redlich–Peterson isotherm models. The findings provide strategic approach for promising material design, supporting the development of potential applications of polyelectrolyte semi-IPN nanocomposite cryogels as biomedical materials.</div></div>","PeriodicalId":245,"journal":{"name":"Applied Clay Science","volume":"269 ","pages":"Article 107763"},"PeriodicalIF":5.3,"publicationDate":"2025-02-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143488395","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Substitution mechanism controls on compositional variations and spectral responses of white micas in major hydrothermal systems","authors":"Junfeng Zhao ,&nbsp;Huayong Chen ,&nbsp;Bing Xiao ,&nbsp;Yabo Zhu ,&nbsp;Hao Wang","doi":"10.1016/j.clay.2025.107762","DOIUrl":"10.1016/j.clay.2025.107762","url":null,"abstract":"<div><div>Whether the shorter or longer wavelengths of diagnostic absorption features of white mica serve as a better vector to mineralization remains controversial. This uncertainty stems from a limited understanding of the compositional substitution mechanisms that control spectral variations. This study compiled published datasets of white mica with both available composition and spectroscopy data from five major hydrothermal systems, including porphyry, epithermal, skarn, orogenic, and volcanogenic massive sulfides (VMS) deposits. Three types of white micas, each dominated by distinct substitution mechanisms—interlayer-dominated (Na⁺ ↔ K⁺, and Ca²⁺, Ba²⁺ ↔ 2 K⁺), Tschermak-dominated (^VIAl³⁺ + ^IVAl³⁺ ↔ ^VIFe²⁺, ^VIMg²⁺ + ^IVSi⁴⁺), and illitic-dominated (K⁺ + ^IVAl³⁺ ↔ ^IVSi⁴⁺ + []_interlayer)—have been identified, accounting for the observed inconsistencies in spectral responses. The interlayer substitution is associated with shorter absorption feature (&lt; 2195 nm) arising from the combination of high-frequency Al₂OH stretching (<em>ν</em>) vibration and bending (δ) vibration. Interlayer-dominated white mica is predominantly found in orogenic deposits, where its presence typically indicates proximal mineralization. Tschermak substitution induces continuous wavelength shifts (2195–2215 nm) in the mid-frequency <em>ν</em> region combined with δ vibration. A high-level of Tschermak reaction stimulates low-frequency ν vibration, producing specific longer absorption feature (&gt; 2215 nm) with δ vibration. Tschermak-dominated white mica is the most widespread among diverse systems. Illitic substitution, however, leads to compositional changes that are not detectable in shortwave infrared (SWIR, 1300–2500 nm) regions, thus rarely providing vectoring indicators. This study suggests that data from white mica characterized by different dominant substitution mechanisms should be distinctly evaluated, thereby enhancing the efficacy of SWIR spectroscopy for mineral exploration.</div></div>","PeriodicalId":245,"journal":{"name":"Applied Clay Science","volume":"269 ","pages":"Article 107762"},"PeriodicalIF":5.3,"publicationDate":"2025-02-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143488397","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}