Aluminum Silicate Minerals Research Articles

MINERALOGICAL AND GEOCHEMICAL STUDY OF ANDESITE ALTERATION ZONE IN BUKIT MANTRI GOLD MINE, BALUNG, SABAH

This paper highlights the geochemical compositions and mineralogy of the alteration zone of the andesitic host rock and volcanic breccia in Bukit Mantri area near Balung, Tawau, Sabah, where a gold mining project is now taking place. Minerals identified by XRD analysis include quartz, pyrite, K-feldspar, muscovite, chlorite, kaolinite, hematite, and goethite, while thin section analysis confirms the abundance of pyrite. XRF and ICP-OES analyses suggest a significant concentration of SO3, Cu, Pb, Zn and As, with average values of 2.68wt%, 254μg/g, 236.9μg/g, 232.9μg/g, and 30.6μg/g, respectively, in the hydrothermally altered andesite. The widespread presence of pyrite and higher concentration of SO3 provide insights for environmental control for its higher acidity generation potential. Meanwhile, secondary minerals such as iron and aluminium oxides and silicate minerals may provide acid buffers and reduce the dispersion of constituents.

Nanogeochemistry of karst-type bauxite from Jingxi, Guangxi, China: Revealing a new occurrence of Al, Si, Ti, Fe, and C by nanoparticles in karst-type bauxite deposit

Karst-type bauxite deposits are an essential source of bauxite. Due to their massive reserves, they have aroused the world's attention. However, there is still controversy about migrating critical elements (such as Si and Al) in bauxite. Various significant nano-mineral particles are discovered in the Jingxi bauxite deposit using transmission electron microscopy (TEM), revealing karst-type bauxite deposits' intricate metallogenic process. These nano-mineral particles provide insight into the occurrence state of ore-forming materials and the element's migration mechanisms using the microscopic nano-geosciences approach. The Jingxi deposit's bauxite samples were discovered to contain many nanoparticles of various shapes and sizes (30–50 nm and over 500 nm), including columnar, granular, and layered forms. These nanoparticles were identified through morphological, chemical, and lattice spacing analyses as scaly diaspore aggregates, columnar rutile particles, layered assemblages of graphite, and kidney-shaped goethite particles. The aluminium silicate mineral (Al, Si, and O) nanoparticles showed in-depth information about the origin of bauxite deposits’ raw materials and endowed a nanometer basis for studying the difficult-to-migrate elements: Al and Si. These nanoparticles confirm an alkaline and reductive metallogenic environment and present nanogeoscience confirmation that igneous rocks are one source of ore-forming components for bauxite.

Novel silicon oxycarbide/spodumene glass-ceramic composites with tailored thermal expansion coefficient

Highly densified silicon oxycarbide (SiOC)/spodumene composites with low coefficient of thermal expansion (CTE) were obtained just selecting the spark plasma sintering temperature employed. For the first time we proposed the use of spodumene a cheap and natural available lithium aluminium silicate mineral as meltable/active filler for SiOC-derived composites, due to its powerful fluxing properties and also its very low CTE. SiOC/spodumene composites sintered at 1200 ⁰C display a very low CTE (0.128±0.004–1.902±0.002 × 10−6 K−1) due to the α,β-transformation of spodumene. At higher sintering temperatures the CTE increases to 3.288±0.004 × 10−6 and 4.516±0.006 × 10−6 K−1 (1300 and 1400 ⁰C) due to the β-SiC formation. In this range of temperature, spodumene promotes the phase separation of SiOC and subsequent crystallization of cristobalite and β-SiC. The maximum values of hardness (11.5 ± 0.5 GPa) and elastic modulus (91±4 MPa) are reached at 1300 ⁰C, where the SiOC/composite displays a neat densification and the lowest roughness (1.61±0.01 nm).

Boom Clay pore-water geochemistry at the Mol site: Chemical equilibrium constraints on the concentrations of major elements

It is important to understand the mechanisms controlling the chemistry of the pore water in the Boom Clay, which has been studied as a reference host rock for the geological disposal of radioactive waste. The chemistry of the pore water and the related properties of the Boom Clay were investigated experimentally. This paper presents the results of equilibrium calculations and discusses the probable chemical constraints that control the concentrations of major elements in the pore water. The present-day Boom Clay pore water is a dilute NaHCO3 solution of 10–20 mM, and the concentration increases with the depth of the Boom Clay over a thickness of 65 m around the underground laboratory at approximately 200 m below sea level. The present-day NaHCO3 water is likely a result of freshwater infiltration, and the concentration profile observed must have been affected by waters from upper and lower aquifers. Among the minerals found in the Boom Clay, equilibrium calculations indicate that the pore water is in equilibrium with calcite, dolomite, siderite, pyrite, and quartz. Aluminium silicate minerals, kaolinite and chlorite, are also possibly in equilibrium, but their saturation states cannot be fully demonstrated mainly because of uncertainties associated with the pore-water concentration of aluminium. Cation exchange, an important property of clays, seems to be controlling only the pore-water concentration of potassium. Concentrations of other cation exchangeable elements, such as calcium and magnesium, are more likely regulated by the solubility of carbonate minerals. On clay surfaces, however, cation-exchange reactions are evidenced and control occupancies of all exchangeable cations. The cation-exchange pool on clay responds to the increase in NaHCO3 concentration with depth, and the surface occupancies vary according to the selectivity of exchangeable cations. Equilibrium calculations allow us to propose a Boom Clay reference model that is able to explain the observed pore-water chemistry. This model is compared to other models in the literature, such as those for the Opalinus Clay in Switzerland and Callovo-Oxfordian Clay in France, which have also been studied for the purpose of radioactive waste disposal. Future studies to improve our understanding of the Boom Clay pore-water geochemistry include i) accurate determination of the pore-water concentration of aluminium, which is crucial for studying the mineral saturation state of aluminium silicates; ii) improving understanding of the mineralogical composition of dolomite in the Boom Clay and its dissolution mechanisms; iii) reassessment of magnesium cation-exchange occupancy on clay surfaces; and iv) improving pore-water sampling and analysis techniques with respect to pH and pCO2 measurements to avoid perturbations to water samples so that the in situ conditions can be preserved to a maximum extent.

Rheological Properties Improvement of Treated Palygorskite Drilling Mud by Adding Prepared Nano Magnesium Oxide

Attapulgite clay is a hydrated magnesium aluminum silicate mineral. Attapulgite clay stone in the Bahr al-Najaf region contains calcite and quartz minerals (43.4%. and 13.9% by weight), respectively. This work is devoted to develop the attapulgite clay found in Bahr Al-Najaf to be suitable for oil wells drilling. The goal of this project is to develop attapulgite mud that meets the American Petroleum Institute (API) for the application of oil well drilling mud in Bahr Al-Najaf. To achieve this objective, unwanted materials (calcite and quartz particles greater than 75 µm in diameter) should be removed and the attapulgite rods dispersed. To make attapulgite mud appropriate for oil well drilling mud. Wet sieving was used to remediate Iraqi attapulgite mud in this study. XRD and SEM tests were done to determine the metals and shape of the prepared Nano MgO to improve the rheological properties. The rheological parameters of attapulgite were measured using an ofite viscometer. Nano MgO was added to attapulgite in three proportions (0.02, 0.05, and 0.08) gm wt. Magnesium oxide showed a great contribution to apparent viscosity and plastic viscosity by 16% of attapulgite aqueous suspensions. The higher viscosity will provide better cuttings carrying capability during drilling fluid circulation especial at low velocity.

Environmentally Friendly Concrete Compressive Strength Prediction Using Hybrid Machine Learning

In order to reduce the adverse effects of concrete on the environment, options for eco-friendly and green concretes are required. For example, geopolymers can be an economically and environmentally sustainable alternative to portland cement. This is accomplished through the utilization of alumina-silicate waste materials as a cementitious binder. These geopolymers are synthesized by activating alumina-silicate minerals with alkali. This paper employs a three-step machine learning (ML) approach in order to estimate the compressive strength of geopolymer concrete. The ML methods include CatBoost regressors, extra trees regressors, and gradient boosting regressors. In addition to the 84 experiments in the literature, 63 geopolymer concretes were constructed and tested. Using Python language programming, machine learning models were built from 147 green concrete samples and four variables. Three of these models were combined using a blending technique. Model performance was evaluated using several metric indices. Both the individual and the hybrid models can predict the compressive strength of geopolymer concrete with high accuracy. However, the hybrid model is claimed to be able to improve the prediction accuracy by 13%.

Upgradation of Iron Ore Fines and Slime by Selective Flocculation Using Surface-Active Agents, Settling Study, and Characterization of the Beneficiation Waste for Value Addition

Washing of iron ore fines and slime (10% and 25% w/v, slurry concentrations) with two types of surface-active agents (sodium humate (synthesized) and AD 200 (commercial)) at varying concentrations at pH 8 was conducted for ascertaining the efficacy of dispersants in beneficiating the low-grade iron ores. The beneficiation process follows the “selective dispersion-cum-settling technique.” The process results in the formation of a dispersed phase rich in gangue minerals and a settled phase of predominantly active hematite mineral. The stability of dispersed phase (DP) was evaluated by determination of the percentage solid content in the DP. Settling tests were performed. First-order kinetic models have been applied to the dispersion-cum-settling behaviour of both the samples, and evaluated kinetic parameters were found to have good agreement with experimental data. Removal of gangue minerals from iron ore depends on the pH of the slurry, concentration of the slurry, and concentration of the surface-active agent used. The surface-active agents at pH 8 produce ∼1.2–1.5 times more stable suspension in the case of iron ore fines and slimes than that of without surface-active agent. They significantly remove gangue minerals and increase the iron value ∼2–7% with ∼58–74% recovery depending on the experimental conditions. The concentrates collected satisfy the required specifications (Al203/Fe < 0.05 and Al203/Si02 < 1). The gangues in the dispersed phase as characterised by “SEM-EDXA” are mostly clay-bearing minerals like kaolinite, goethite, chlorite, and alumina-silicate minerals. Heat treatment causes distortion of clay minerals present in the dispersed phase and also indicates the complex nature of the gangue minerals.

Halloysite-Based Nanosystems for Biomedical Applications

AbstractHalloysite nanotubes (HNTs) are hollow clay nanotubes in the nanometer size range, made up of double-layered aluminum silicate mineral layers. HNTs represent an extremely versatile, safe, and biocompatible nanomaterial, used in a wide range of applications in biomedicine and nanomedicine. For example, they are used as transporters for the controlled release of drugs or genes, in tissue engineering, in the isolation of stem cells and cancer cells, and in bioimaging. Consequently, the assessment of the biocompatibility of HNTs has acquired considerable importance. In recent years, HNT composites have attracted attention due to their improved biocompatibility, compared to HNTs, suggesting potential for applications in tissue engineering or as vehicles for drugs or genes. In this review, recent advances in the application of HNTs and HNT composites in biomedicine are discussed to provide a valuable guide to scientists in the design and development of viable, functional bio-devices for biomedical applications.

Experimental Study on the Self-Healing Behavior of Fractured Rocks Induced by Water-CO2-Rock Interactions in the Shendong Coalfield

This study experimentally investigated the self-healing behavior, referring to the naturally occurring water permeability decrease, of fractured rocks exposed to water-CO2-rock interaction (WCRI). The experiment was conducted on prefractured specimens of three rock types typical of the Shendong coalfield: coarse-grained sandrock, fine-grained sandrock, and sandy mudrock. During the experiment, which ran for nearly 15 months, all three specimens exhibited decreasing permeabilities. The coarse- and fine-grained sandrock specimens exhibited smooth decreases in permeability, with approximately parallel permeability time curves, whereas that of the sandy mudrock specimen decreased rapidly during the initial stage and slowly during later stages. The sandrock specimens were rich in feldspars, which were dissolved and/or corroded and involved in ionic exchange reactions with CO2 and groundwater, thereby generating secondary minerals (such as kaolinite, quartz, and sericite) or CaSO4 sediments. These derivative matters adhered to the fracture surface, thereby gradually repairing fractures and decreasing the water permeability of the fractured rocks. In comparison, the sandy mudrock had a high content of clay minerals, and the water-rock interaction caused rapid expansions of illite, mixed illite-smectite, and other clay minerals, thereby narrowing the fractures and causing the rapid permeability decrease during the initial stage. In later stages, the derivative matters generated by the dissolution and/or corrosion of feldspars and other aluminum silicate minerals in the mudrock filled and sealed the fractures, causing the slow permeability decreases during the later stages, as in the sandrock specimens. Neutral and basic groundwater conditions facilitated better self-healing of fractured mudrocks rich in clay minerals, whereas acidic groundwater conditions and the presence of CO2 facilitated better self-healing of fractured sandrocks. Thus, this study’s results are of significant value to aquifer restoration efforts in the Shendong coalfield and other ecologically vulnerable mining areas.

Mineralogical and Geotechnical Properties of Clay Minerals in Northern Borno, Nigeria

Clay generally refers to either fine grained earth material with particle size of less than two micron (< 2 m) or group of hydrous aluminum silicate minerals that are characterized by sheet silicate structure of composite layers stacked along the C-axis. They are common deposits found in most geological setting like in fine grained sedimentary rocks such as shale, mudstone, and siltstone, in fine grained metamorphic slate and phyllite. The interest in clay deposits arises from its numerous uses of the mineral group and the behaviour of soils constituents when used as engineering soil and its resultant effects on engineering structures like roads, dams, bridges and houses. Evaluation of the soil properties of the Chad Formation indicated that the plasticity characteristics of the samples are of low to medium plasticity as indicated by matching the result with the DIN. chart. The results of free swell showed that the samples are susceptible to swelling when they absorbed water. The particle size distribution tests indicate that the percentage of fine (i.e. samples passing the 75µm sieve) is about 1.7 % implying that the grain sizes are within the texture of medium grain fraction

Mineralogical and Geotechnical Properties of Clay Minerals in Northern Borno, Nigeria

Clay generally refers to either fine grained earth material with particle size of less than two micron (< 2 m) or group of hydrous aluminum silicate minerals that are characterized by sheet silicate structure of composite layers stacked along the C-axis. They are common deposits found in most geological setting like in fine grained sedimentary rocks such as shale, mudstone, and siltstone, in fine grained metamorphic slate and phyllite. The interest in clay deposits arises from its numerous uses of the mineral group and the behaviour of soils constituents when used as engineering soil and its resultant effects on engineering structures like roads, dams, bridges and houses. Evaluation of the soil properties of the Chad Formation indicated that the plasticity characteristics of the samples are of low to medium plasticity as indicated by matching the result with the DIN. chart. The results of free swell showed that the samples are susceptible to swelling when they absorbed water. The particle size distribution tests indicate that the percentage of fine (i.e. samples passing the 75µm sieve) is about 1.7 % implying that the grain sizes are within the texture of medium grain fraction

Roasting of pyrophyllite for application in aluminoborosilicate glass production

ABSTRACT Pyrophyllite, an aluminum silicate mineral, was used as a raw material for the production of aluminoborosilicate glass. For the application of pyrophyllite to the glass manufacturing process as a raw material, the particle size distribution of the powder must the following requirements: 150–45 μm ≥ 60 mass% and below 45 μm ≤ 40 mass%. Hence, an attempt was made to develop the technology for pyrophyllite to produce a powder that meets these requirements through understanding the crushing characteristics. Roasting of pyrophyllite at 1150 °C resulted in the alternation of raw pyrophyllite and led to differences in the crushing characteristics. Crushing of the roasted pyrophyllite produced a powder with a reduction in the amount of the fine particles (−45 μm) compared to the powder of the raw pyrophyllite under identical crushing condition. This difference is attributed to the alternation of the raw pyrophyllite after the roasting process, as confirmed by powder X-ray diffraction (XRD) and scanning electron microscopy (SEM) results as well as by the amount of water adsorption. The melting characteristics of the raw and roasted pyrophyllite samples were investigated for application to the aluminumborosilicate glass production. The glass products are characterized as colorless and in an amorphous phase.

Preparation of three-dimensional palygorskite based carrier

Palygorskite is a kind of crystalline hydrated magnesium aluminum silicate mineral with micro-fibrous morphology. Due to the large specific surface area, moderate cationic exchange capacity and pronounced adsorption properties, it has been widely used in many fields. In order to enhance the loading capacity and adjust the microstructure of palygorskite (Pal) crystal, series of three-dimensional palygorskite carriers (3D Pal) with different pore size were fabricated through grafting from or grafting onto method. Due to the functional and cross-linked molecules act as upholder reagents, the specific surface of individual palygorskite is fully utilized and the load capacity is greatly improved. The porosity and pore size of 3D palygorskite based carrier also can be regulated by the length of organic molecular chain segments. The successful preparation of 3D Pal-based carrier provides a new way for surface grafting, modification or preparing 3D carrier of palygorskite and other minerals.•The developed method allows fabricating three-dimensional palygorskite based carriers by covalent bonding method.•The pore size of the as-prepared carriers can be conveniently adjusted by length of the bonded molecular chain.

On the occurrence of gallium and germanium in the Bergslagen ore province, Sweden

ABSTRACTThe presence of the critical and sought-after (semi-)metals gallium (Ga) and germanium (Ge) has previously been reported from mineralisations in the Bergslagen ore province, south central Sweden. Some of these reports were however recently shown to be questionable or erroneous. Here we summarise early analytical work on these metals in mineral deposits of the Bergslagen province, as well as briefly report new analytical data for Ga and Ge from recent, in part on-going work on different mineralisation types. The new data show that the sampled sulphide and iron oxide mineralisations in the Bergslagen province are overall not particularly enriched in Ga, and even less so with regards to Ge. One major exception is the significant Ga enrichment observed in skarn-hosted Fe-REE(-polymetallic) deposits of Bastnäs type. Notably, these mineralisations also host increased contents of Ge. Based on this broader suite of sampled deposits, the suggested correlation between Ga and Al contents in previously studied material with relatively increased Ga grades, is in part contradicted, indicating that Ga is only in part sequestered through straightforward Al-substitution into aluminium silicate and oxide minerals. The mineralisations that do exhibit significantly increased Ge contents, in addition to the Bastnäs-type deposits, are represented by both sulphide-dominated ones and Fe (-Mn) oxide-rich systems.

Inclusion of geopolymers derivate from fly ash and pumice in reinforced concrete

This paper presents results of a research project related to the development of alkali-activated geopolymers, synthesized from alumina-silicate minerals (fly ash and pumice) which are added to concrete. Alkali sources used in geopolymer synthesis were sodium hydroxide and sodium silicate solution. New materials were structurally characterized by Infra-Red spectroscopy (IR) and X-Ray Diffraction (XRD). Concretes obtained after geopolymers addition as Portland cement substitutes at 10%, 20% and 30%, were mechanically analysed by compression resistance at 7, 14, 28 and 90 drying days. Results were referred to standard (concrete of Portland cement) allows to know cementitious characteristics of geopolymers are lower than those for standard, but it keeps growing at longer drying time than Portland cement. By Electrochemical Impedance Spectroscopy (EIS) it is found that this new material shows high electrical resistance and have been proved as a protection agent against corrosion in reinforced concrete exhibiting anticorrosive properties higher than those showed by the conventional concrete mixture.

Removal of Insoluble Slimes from Potash Ore Using Flotation

AbstractThe low grade potash ores contain large amount of fine water insoluble minerals, which was defined as slime here. The removal of the slime from the low grade of potash ores (KCl < 10 %; slime > 40 %) from the Mahai Basin, Qinghai Province, PRC, was investigated using flotation. The characteristics of the slime sample, which was extracted from the potash ores sample, were examined by X-Ray Fluorescence Spectrometry and X-Ray Diffraction. It was found that more than 70 % of the slime was aluminum silicate minerals including feldspar, clay (phyllosilicates), silt, as well as gypsum and carbonate minerals. In this study the flotation response of the slime minerals was evaluated. It was found that a higher slime flotation recovery of the slime was obtained when the MR-1 surfactant (polyoxyethylene fatty acid ester)-kerosene-water emulsion was used as collector. Fourier Transform Infrared Spectrometry (FTIR Spectrometry), oil spreading, and contact angle results indicated that the MR-1 surfactant is selectively adsorbed on slime minerals surfaces and facilitates the spreading of kerosene.

Moth proofing of wool fabric using nano kaolinite

Woollen products are susceptible to the attack of wool moth. An attempt was made to impart anti moth property to woollen fabric using nano kaolinite, an aluminium silicate mineral based of natural origin. The treatment of nano kaolinite on wool fabric was conducted both at room temperature and 80 °C for the optimization of the process. The characterization of nano kaolinite as well as nano kaolinite-coated wool fabric was performed with various analytical techniques. Moth proofing performance of nano kaolinite-coated wool fabric against Anthrenus verbasci was investigated through assessing wool weight loss and number of moth alive after the incubation period of 15 days. It was found that 1.0% nano kaolinite treatment at room temperature treatment is found to be more effective than high-temperature treatment in terms of weight loss and mortality rate of wool moth. The results were compared with a commercial anti moth agent.

Investigations on the mechanism, kinetics and isotherms of ammonium and humic acid co-adsorption at low temperature by 4A-molecular sieves modified from attapulgite

Attapulgite (ATP) is a type of natural magnesium aluminum silicate mineral and has been applied as an adsorbent to remove organic pollutants and heavy metals in aqueous solution.

Does blending the ashes of chestnut shell and lignite create synergistic interaction on ash fusion temperatures?

The ashes of twelve different Turkish lignites were blended with the ash of chestnut shell (20wt.%) to investigate the effects of the biomass ash on the ash fusion temperatures (AFTs) of the ashes of coal/biomass blends. Fusion characteristics of ashes were studied according to ASTM D1857. Calculated values (theoretical values) of AFTs were compared with the experimental ones to evaluate the existence of additive behavior or synergistic/antagonistic interactions between the ashes. It was found that the presence of the ash of chestnut shell led to more or less lowering trends in AFTs in eleven of the twelve lignite ashes and this is an undesirable interaction. Although, the chestnut shell contains high amount of Ca, it was concluded that the improving effect of Ca on ash fusion temperatures are overtaken by the lowering effect of K. Alumina-silicate minerals in lignite ashes may show interaction with K to form new phases with low melting temperatures. Consequently, it was found out that the increasing acidic oxides (SiO2+Al2O3+TiO2) in ash leads to high levels of deviations from the calculated values (additive behavior) of AFTs and particularly the Al content is the key parameter.

A SEM, EDS and vibrational spectroscopic study of the clay mineral fraipontite

The mineral fraipontite has been studied by using a combination of scanning electron microscopy with energy dispersive analysis and vibrational spectroscopy (infrared and Raman). Fraipontite is a member of the 1:1 clay minerals of the kaolinite-serpentine group. The mineral contains Zn and Cu and is of formula (Cu,Zn,Al)3(Si,Al)2O5(OH)4. Qualitative chemical analysis of fraipontite shows an aluminium silicate mineral with amounts of Cu and Zn. This kaolinite type mineral has been characterised by Raman and infrared spectroscopy; in this way aspects about the molecular structure of fraipontite clay are elucidated.