Special Issue "Nanomineralogy"

A special issue of Minerals (ISSN 2075-163X). This special issue belongs to the section "Crystallography and Physical Chemistry of Minerals".

Deadline for manuscript submissions: closed (30 April 2019)

Special Issue Editors

Guest Editor
Prof. Dr. Yiwen Ju

College of Earth and Planetary Sciences, University of Chinese Academy of Sciences, Beijing 100049, P.R. China
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Interests: nanogeoscience; structural geology; unconventional energy geology; coal; shale; gas geology; ore deposits; basin geology
Guest Editor
Prof. Dr. Quan Wan

Institute of Geochemistry, Chinese Academy of Sciences, Guiyang, Guizhou 550081, P.R. China
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Interests: nanogeoscience; mineral–water interface; sorption; nanopore confinement; shale gas; nanoparticles in ore deposits
Guest Editor
Prof. Dr. Michael F. Hochella, Jr.

Department of Geosciences, Virginia Tech, Blacksburg, VA 24060, USA
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Interests: nanogeoscience; mineral surface geochemistry; biogeochemistry; environmental science; mineral–microbe interactions

Special Issue Information

Dear Colleagues,

The 2018 International Conference on Nanogeosciences was held in Guiyang, China between June 22nd and 27th, 2018. Researchers from around the world gathered together and actively discussed emerging challenges and opportunities in numerous fields of nanogeosciences. This Special Issue of Minerals aims to showcase recent advances in the wide range of themes in nanogeosciences, with a substantial focus on the nanoscale research in mineralogy. We invite attendees of the nanogeosciences conference to submit selected high quality manuscripts to this Special Issue. Suitable contributions from other interested professionals are also welcome.

The first round submission deadline is: 31 March 2019

Prof. Dr. Yiwen Ju
Prof. Dr. Quan Wan
Prof. Dr. Michael F. Hochella, Jr.
Guest Editors

Manuscript Submission Information

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Submitted manuscripts should not have been published previously, nor be under consideration for publication elsewhere (except conference proceedings papers). All manuscripts are thoroughly refereed through a single-blind peer-review process. A guide for authors and other relevant information for submission of manuscripts is available on the Instructions for Authors page. Minerals is an international peer-reviewed open access monthly journal published by MDPI.

Please visit the Instructions for Authors page before submitting a manuscript. The Article Processing Charge (APC) for publication in this open access journal is 1400 CHF (Swiss Francs). Submitted papers should be well formatted and use good English. Authors may use MDPI's English editing service prior to publication or during author revisions.

Keywords

  • Nanogeoscience
  • Nanomineralogy
  • Nanominerals
  • Mineral nanoparticles
  • Nanopores
  • Nanogeochemistry
  • Mineral–water interface

Published Papers (11 papers)

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Research

Open AccessArticle
Enhanced Potential Toxic Metal Removal Using a Novel Hierarchical SiO2–Mg(OH)2 Nanocomposite Derived from Sepiolite
Minerals 2019, 9(5), 298; https://doi.org/10.3390/min9050298
Received: 9 April 2019 / Revised: 14 May 2019 / Accepted: 14 May 2019 / Published: 15 May 2019
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Abstract
Clays are widely used as sorbents for heavy metals due to their high specific surface areas, low cost, and ubiquitous occurrence in most soil and sediment environments. However, the low loading capacity for heavy metals is one of their inherent limitations. In this [...] Read more.
Clays are widely used as sorbents for heavy metals due to their high specific surface areas, low cost, and ubiquitous occurrence in most soil and sediment environments. However, the low loading capacity for heavy metals is one of their inherent limitations. In this work, a novel SiO2–Mg(OH)2 nanocomposite was successfully prepared via sequential acid–base modification of raw sepiolite. The structural characteristics of the resulting modified samples were characterized by a wide range of techniques including field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), energy dispersive X-ray spectroscopy (EDX), X-ray diffraction (XRD), and nitrogen physisorption analysis. The results show that a hierarchical nanocomposite constructed by loading the Mg(OH)2 nanosheets onto amorphous SiO2 nanotubes can be successfully prepared, and the nanocomposite has a high surface area (377.3 m2/g) and pore volume (0.96 cm3/g). Batch removal experiments indicate that the nanocomposite exhibits high removal efficiency toward Gd(III), Pb(II), and Cd(II), and their removal capacities were greatly enhanced in comparison with raw sepiolite, due to the synergistic effect of the different components in the hierarchical nanocomposite. This work can provide a novel route toward a hierarchical nanocomposite by using clay minerals as raw material. Taking into account the simplicity of the fabrication route and the high loading capacities for heavy metals, the developed nanocomposite also has great potential applications in water treatment. Full article
(This article belongs to the Special Issue Nanomineralogy)
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Open AccessFeature PaperArticle
Iron-Rich Nanoparticles in Natural Aquatic Environments
Minerals 2019, 9(5), 287; https://doi.org/10.3390/min9050287
Received: 8 April 2019 / Revised: 26 April 2019 / Accepted: 27 April 2019 / Published: 11 May 2019
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Abstract
Naturally-occurring iron nanoparticles constitute a quantitatively-important and biogeochemically-active component of the broader Earth ecosystem. Yet detailed insights into their chemical speciation is sparse compared to the body of work conducted on engineered Fe nanoparticles. The present contribution briefly reviews the analytical approaches that [...] Read more.
Naturally-occurring iron nanoparticles constitute a quantitatively-important and biogeochemically-active component of the broader Earth ecosystem. Yet detailed insights into their chemical speciation is sparse compared to the body of work conducted on engineered Fe nanoparticles. The present contribution briefly reviews the analytical approaches that can be used to characterize natural Fe nanoparticles, before detailing a dedicated synchrotron-based X-ray spectro-microscopic investigation into the speciation of suspended Fe nanoparticles collected from fluvial, marine, and lacustrine surface waters. Ferrous, ferric and magnetite classes of Fe nanoparticles (10–100 nm) were identified, and all three classes exhibited a high degree of heterogeneity in the local bonding environment around the Fe center. The heterogeneity is attributed to the possible presence of nanoparticle aggregates, and to the low degrees of crystallinity and ubiquitous presence of impurities (Al and organic moieties) in natural samples. This heterogeneity further precludes a spectroscopic distinction between the Fe nanoparticles and the larger sized Fe-rich particles that were evaluated. The presented results provide an important baseline for natural nanoparticle speciation in pristine aquatic systems, highlight the degree of inter-particle variability, which should be parameterized in future accurate biogeochemical models, and may inform predictions of the fate of released engineered Fe nanoparticles as they evolve and transform in natural systems. Full article
(This article belongs to the Special Issue Nanomineralogy)
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Open AccessArticle
Facile Hydrothermal Synthesis of Nanocubic Pyrite Crystals Using Greigite Fe3S4 and Thiourea as Precursors
Minerals 2019, 9(5), 273; https://doi.org/10.3390/min9050273
Received: 2 April 2019 / Revised: 28 April 2019 / Accepted: 29 April 2019 / Published: 1 May 2019
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Abstract
Nanocubic pyrite (FeS2) crystals with exposed (100) crystal faces and sizes of 100–200 nm were successfully synthesized via a facile hydrothermal method using greigite (Fe3S4) as the iron precursor and thiourea (NH2CSNH2) as [...] Read more.
Nanocubic pyrite (FeS2) crystals with exposed (100) crystal faces and sizes of 100–200 nm were successfully synthesized via a facile hydrothermal method using greigite (Fe3S4) as the iron precursor and thiourea (NH2CSNH2) as the sulfur source. When the concentration of thiourea was 40 mmol/L, both pyrite and hematite were observed in the as-prepared sample, indicating incomplete conversion of greigite into pyrite. With an increased thiourea concentration to 80 mmol/L, pyrite was found to be the only crystalline phase in the synthesized samples. All greigite could be transformed to pyrite within 24 h via the hydrothermal method, while further prolonging the hydrothermal time had insignificant effect on the crystal phase composition, crystallinity, and morphologies of the prepared nanocubic pyrite crystals. In contrast, when a mixture of Na2S and S powder was used to replace the thiourea as the sulfur source, tetragonal, orthorhombic, cubic, and irregular pyrite crystal particles with sizes of 100 nm–1 μm were found to co-exist in the prepared samples. These results demonstrate the critical influence of sulfur source on pyrite morphology. Furthermore, our hydrothermal process, using a combination of greigite and thiourea, is proved to be effective in preparing nanocubic pyrite crystals. Our findings can also provide new insight into the formation environments and pathways of nanocubic pyrite under hydrothermal conditions. Full article
(This article belongs to the Special Issue Nanomineralogy)
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Open AccessArticle
The Characterization and Amoxicillin Adsorption Activity of Mesopore CaCO3 Microparticles Prepared Using Rape Flower Pollen
Minerals 2019, 9(4), 254; https://doi.org/10.3390/min9040254
Received: 29 March 2019 / Revised: 19 April 2019 / Accepted: 21 April 2019 / Published: 25 April 2019
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Abstract
A precipitation reaction method was employed to prepare mesopore calcium carbonate (CaCO3) using rape flower pollen as the template. CaCO3 adsorbent was characterized using X-ray diffraction (XRD), scanning electronic microscopy (SEM), and Brunner−Emmet−Teller measurements (BET). The equilibrium adsorption data on [...] Read more.
A precipitation reaction method was employed to prepare mesopore calcium carbonate (CaCO3) using rape flower pollen as the template. CaCO3 adsorbent was characterized using X-ray diffraction (XRD), scanning electronic microscopy (SEM), and Brunner−Emmet−Teller measurements (BET). The equilibrium adsorption data on amoxicillin were explained using Langmuir, Freundlich, and Temkin adsorption isotherm models. The pseudo-first order, second order, pseudo-second order, and intra-particle diffusion kinetic models were used to explore adsorption kinetics. Equilibrium adsorption of as-prepared CaCO3 was better depicted using the Langmuir adsorption model with an R2 of 0.9948. The separation factor (RL) was found to be in the range of 0 < RL < 1, indicating the favorable adsorption of amoxicillin. The adsorption capacity of mesopore CaCO3 reached 13.49 mg·g−1 in 0.2 g∙L−1 amoxicillin solution. The values of adsorption thermodynamic parameters (ΔHθ, ΔSθ, ΔGθ) were obtained. In addition, the adsorption process turned out to be endothermic and spontaneous for the CaCO3 product at 298 K, 308 K, and 318 K. Full article
(This article belongs to the Special Issue Nanomineralogy)
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Open AccessArticle
Fractal Characteristics and Heterogeneity of the Nanopore Structure of Marine Shale in Southern North China
Minerals 2019, 9(4), 242; https://doi.org/10.3390/min9040242
Received: 11 March 2019 / Revised: 10 April 2019 / Accepted: 17 April 2019 / Published: 19 April 2019
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Abstract
The characteristics of the nanopore structure in shale play a crucial role in methane adsorption and in determining the occurrence and migration of shale gas. In this study, using an integrated approach of X-ray diffraction (XRD), N2 adsorption, and field emission scanning [...] Read more.
The characteristics of the nanopore structure in shale play a crucial role in methane adsorption and in determining the occurrence and migration of shale gas. In this study, using an integrated approach of X-ray diffraction (XRD), N2 adsorption, and field emission scanning electron microscopy (FE-SEM), we systematically focused on eight drilling samples of marine Taiyuan shale from well ZK1 in southern North China to study the characteristics and heterogeneity of their nanopore structure. The results indicated that different sedimentary environments may control the precipitation of clay and quartz between transitional shale and marine shale, leading to different organic matter (OM)–clay relationships and different correlations between total organic carbon (TOC) and mineral content. The shale with high TOC content tended to have more heterogeneous micropores, leading to a higher fractal dimension and a more complex nanopore structure. With the increase of TOC content and thermal evolution of OM, the heterogeneity of the pore structure became more significant. Quartz from marine shale possessed abundant macropores, resulting in a decrease of the Brunauere–Emmette–Teller (BET) surface area (SA) and an increase of the average pore size (APS), while clay minerals developed a large number of micropores which worked together with OM to influence the nanopore structure of shale, leading to the increase of the SA and the decrease of the APS. The spatial order of interlayer pores increased with the increase of mixed-layer illite–smectite (MLIS) content, which naturally reduced the fractal dimensions. In contrast, kaolinite, chlorite, and illite have a small number of nanopores, which might enhance the complexity and reduce the connectivity of the nanopore system by mean of pore-blocking. Taiyuan shale with higher heterogeneity is highly fractal, and its fractal dimensions are principally related to the micropores. The fractal dimensions correlate positively with the SA and total pore volume, suggesting that marine shale with higher heterogeneity may possess a larger SA and a higher total pore volume. Full article
(This article belongs to the Special Issue Nanomineralogy)
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Open AccessArticle
Two Hydrothermal Events at the Shuiyindong Carlin-Type Gold Deposit in Southwestern China: Insight from Sm–Nd Dating of Fluorite and Calcite
Minerals 2019, 9(4), 230; https://doi.org/10.3390/min9040230
Received: 8 March 2019 / Revised: 4 April 2019 / Accepted: 4 April 2019 / Published: 12 April 2019
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Abstract
The Shuiyindong Gold Mine hosts one of the largest and highest-grade, strata-bound Carlin-type gold deposits discovered to date in Southwestern China. The outcrop stratigraphy and drill core data of the deposit reveal Middle–Upper Permian and Lower Triassic formations. The ore is mainly hosted [...] Read more.
The Shuiyindong Gold Mine hosts one of the largest and highest-grade, strata-bound Carlin-type gold deposits discovered to date in Southwestern China. The outcrop stratigraphy and drill core data of the deposit reveal Middle–Upper Permian and Lower Triassic formations. The ore is mainly hosted in Upper Permian bioclastic limestone near the axis of an anticline. The gold is mainly hosted in arsenian pyrite and arsenopyrite, mainly existing in the form of crystal lattice gold, submicroscopic particles and nanoparticles. Fluorite commonly occurs at the vicinity of an unconformity between the Middle–Upper Permian formations, which is proposed to be the structural conduit that fed the ore fluids. Calcite commonly fills fractures at the periphery of decarbonated rocks, which contain high grade orebodies. This study aimed to verify the occurrence of two distinct hydrothermal events at the Shuiyindong, based on Sm–Nd isotope dating of the fluorite and calcite. For this purpose, rare-earth element (REE) concentrations, Sm/Nd isotope ratios, and Sm–Nd isochron ages of the fluorite and calcite were determined. The fluorite and calcite contain relatively high total concentrations of REE (12.3–25.6 μg/g and 5.71–31.7 μg/g, respectively), exhibit variable Sm/Nd ratios (0.52–1.03 and 0.57–1.71, respectively), and yield Sm–Nd isochron ages of 200.1 ± 8.6 Ma and 150.2 ± 2.2 Ma, with slightly different initial ε Nd ( t ) values of −4.4 and −1.1, respectively. These two groups of Sm–Nd isochron ages suggest two episodes of hydrothermal events at the Shuiyindong gold deposit. The age of the calcite probably represents the late stage of the gold mineralization period. The initial ε Nd ( t ) values of the fluorite and calcite indicate that the Nd was probably derived from mixtures of basaltic volcanic tuff and bioclastic limestone from the Permian formations. Full article
(This article belongs to the Special Issue Nanomineralogy)
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Open AccessArticle
Pore Connectivity Characterization of Lacustrine Shales in Changling Fault Depression, Songliao Basin, China: Insights into the Effects of Mineral Compositions on Connected Pores
Minerals 2019, 9(3), 198; https://doi.org/10.3390/min9030198
Received: 22 February 2019 / Revised: 14 March 2019 / Accepted: 22 March 2019 / Published: 26 March 2019
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Abstract
Pore connectivity of lacustrine shales was inadequately documented in previous papers. In this work, lacustrine shales from the lower Cretaceous Shahezi Formation in the Changling Fault Depression (CFD) were investigated using field emission scanning electron microscopy (FE-SEM), mercury intrusion capillary pressure (MICP), low [...] Read more.
Pore connectivity of lacustrine shales was inadequately documented in previous papers. In this work, lacustrine shales from the lower Cretaceous Shahezi Formation in the Changling Fault Depression (CFD) were investigated using field emission scanning electron microscopy (FE-SEM), mercury intrusion capillary pressure (MICP), low pressure gas (CO2 and N2) sorption (LPGA) and spontaneous fluid imbibition (SFI) experiments. The results show that pores observed from FE-SEM images are primarily interparticle (interP) pores in clay minerals and organic matter (OM) pores. The dominant pore width obtained from LPGA and MICP data is in the range of 0.3–0.7 nm and 3–20 nm. The slopes of n-decane and deionized (DI) water SFI are in the range of 0.34–0.55 and 0.22–0.38, respectively, suggesting a mixed wetting nature and better-connected hydrophobic pores than hydrophilic pores in the Shahezi shales. Low pore connectivity is identified by the dominant nano-size pore widths (0.3–20 nm), low DI water SFI slopes (around 0.25), high geometric tortuosity (4.75–8.89) and effective tortuosity (1212–6122). Pore connectivity follows the order of calcareous shale > argillaceous shale > siliceous shale. The connected pores of Shahezi shales is mainly affected by the high abundance and coexistence of OM pores and clay, carbonate minerals host pores. Full article
(This article belongs to the Special Issue Nanomineralogy)
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Open AccessArticle
The Impacts of Matrix Compositions on Nanopore Structure and Fractal Characteristics of Lacustrine Shales from the Changling Fault Depression, Songliao Basin, China
Minerals 2019, 9(2), 127; https://doi.org/10.3390/min9020127
Received: 13 January 2019 / Revised: 11 February 2019 / Accepted: 15 February 2019 / Published: 22 February 2019
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Abstract
The Lower Cretaceous Shahezi shales are the targets for lacustrine shale gas exploration in Changling Fault Depression (CFD), Southern Songliao Basin. In this study, the Shahezi shales were investigated to further understand the impacts of rock compositions, including organic matters and minerals on [...] Read more.
The Lower Cretaceous Shahezi shales are the targets for lacustrine shale gas exploration in Changling Fault Depression (CFD), Southern Songliao Basin. In this study, the Shahezi shales were investigated to further understand the impacts of rock compositions, including organic matters and minerals on pore structure and fractal characteristics. An integrated experiment procedure, including total organic carbon (TOC) content, X-ray diffraction (XRD), field emission-scanning electron microscope (FE-SEM), low pressure nitrogen physisorption (LPNP), and mercury intrusion capillary pressure (MICP), was conducted. Seven lithofacies can be identified according to on a mineralogy-based classification scheme for shales. Inorganic mineral hosted pores are the most abundant pore type, while relatively few organic matter (OM) pores are observed in FE-SEM images of the Shahezi shales. Multimodal pore size distribution characteristics were shown in pore width ranges of 0.5–0.9 nm, 3–6 nm, and 10–40 nm. The primary controlling factors for pore structure in Shahezi shales are clay minerals rather than OM. Organic-medium mixed shale (OMMS) has the highest total pore volumes (0.0353 mL/g), followed by organic-rich mixed shale (ORMS) (0.02369 mL/g), while the organic-poor shale (OPS) has the lowest pore volumes of 0.0122 mL/g. Fractal dimensions D1 and D2 (at relative pressures of 0–0.5 and 0.5–1 of LPNP isotherms) were obtained using the Frenkel–Halsey–Hill (FHH) method, with D1 ranging from 2.0336 to 2.5957, and D2 between 2.5779 and 2.8821. Fractal dimensions are associated with specific lithofacies, because each lithofacies has a distinctive composition. Organic-medium argillaceous shale (OMAS), rich in clay, have comparatively high fractal dimension D1. In addition, organic-medium argillaceous shale (ORAS), rich in TOC, have comparatively high fractal dimension D2. OPS shale contains more siliceous and less TOC, with the lowest D1 and D2. Factor analysis indicates that clay contents is the most significant factor controlling the fractal dimensions of the lacustrine Shahezi shale. Full article
(This article belongs to the Special Issue Nanomineralogy)
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Open AccessArticle
Green Preparation of Nanoporous Pyrrhotite by Thermal Treatment of Pyrite as an Effective Hg(Ⅱ) Adsorbent: Performance and Mechanism
Minerals 2019, 9(2), 74; https://doi.org/10.3390/min9020074
Received: 10 November 2018 / Revised: 13 January 2019 / Accepted: 22 January 2019 / Published: 27 January 2019
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Abstract
The removal of Hg(II) from aqueous solutions by pyrrhotite derived from the thermal activation of natural pyrite was explored by batch experiments. The adsorption isotherms demonstrated that the sorption of Hg(II) by modified pyrite (MPy) can be fitted well by the Langmuir model. [...] Read more.
The removal of Hg(II) from aqueous solutions by pyrrhotite derived from the thermal activation of natural pyrite was explored by batch experiments. The adsorption isotherms demonstrated that the sorption of Hg(II) by modified pyrite (MPy) can be fitted well by the Langmuir model. The removal capacity of Hg(II) on MPy derived from the Langmuir model was determined to 166.67 mg/g. The adsorption process of Hg(II) on MPy was well fitted by a pseudo-second-order model. The sorption of Hg(II) on MPy was a spontaneous and endothermic process. The removal of Hg(II) by MPy was mainly attributed to a chemical reaction resulting in cinnabar formation and the electrostatic attraction between the negative charges in MPy and positive charges of Hg(II). The results of our work suggest that the thermal activation of natural pyrite is greatly important for the effective utilization of ore resources for the removal of Hg(II). Full article
(This article belongs to the Special Issue Nanomineralogy)
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Open AccessArticle
Total Porosity Measured for Shale Gas Reservoir Samples: A Case from the Lower Silurian Longmaxi Formation in Southeast Chongqing, China
Minerals 2019, 9(1), 5; https://doi.org/10.3390/min9010005
Received: 22 November 2018 / Revised: 18 December 2018 / Accepted: 21 December 2018 / Published: 22 December 2018
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Abstract
Measuring total porosity in shale gas reservoir samples remains a challenge because of the fine-grained texture, low porosity, ultra-low permeability, and high content of organic matter (OM) and clay mineral. The composition content porosimetry method, which is a new method for the evaluation [...] Read more.
Measuring total porosity in shale gas reservoir samples remains a challenge because of the fine-grained texture, low porosity, ultra-low permeability, and high content of organic matter (OM) and clay mineral. The composition content porosimetry method, which is a new method for the evaluation of the porosity of shale samples, was used in this study to measure the total porosity of shale gas reservoir samples from the Lower Silurian Longmaxi Formation in Southeast Chongqing, China, based on the bulk and grain density values. The results from the composition content porosimetry method were compared with those of the Gas Research Institute method. The results showed that the composition content porosimetry porosity values of shale gas reservoir samples range between 2.05% and 5.87% with an average value of 4.04%. The composition content porosimetry porosity generally increases with increasing OM and clay content, and decreases with increasing quartz and feldspar content. The composition content porosimetry results are similar to the gas research institute results, and the differences between the two methods range from 0.05% to 1.52% with an average value of 0.85%. Full article
(This article belongs to the Special Issue Nanomineralogy)
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Open AccessArticle
One-Step Synthesis of Hydroxysodalite Using Natural Bentonite at Moderate Temperatures
Minerals 2018, 8(11), 521; https://doi.org/10.3390/min8110521
Received: 19 September 2018 / Revised: 2 November 2018 / Accepted: 6 November 2018 / Published: 9 November 2018
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Abstract
Ca-bentonite was used as the feedstock material for the synthesis of hydroxysodalite due to its high Al, Si content, good chemical reactivity, and natural abundance. A one-step method is proposed here to fabricate hydroxysodalite in a water bath at moderate temperature. The effects [...] Read more.
Ca-bentonite was used as the feedstock material for the synthesis of hydroxysodalite due to its high Al, Si content, good chemical reactivity, and natural abundance. A one-step method is proposed here to fabricate hydroxysodalite in a water bath at moderate temperature. The effects of the Na/Si molar ratio, Si/Al molar ratio, reaction time, and reaction temperature on the synthesis of hydroxysodalite have been systematically investigated here. The crystallizing phases and morphology of the synthetic products were characterized using X-ray diffraction (XRD) and scanning electron microscopy (SEM), respectively. The results showed that the Na/Si molar ratio and reaction temperature both played important roles in controlling the degree of crystallinity of the synthetic hydroxysodalite. The Si/Al molar ratio and reaction time both affect the purity of the synthetic hydroxysodalite. Optimum conditions for synthesizing hydroxysodalite using a one-step water-bath method at moderate temperature are as follows: a Na/Si molar ratio of 12, a Si/Al molar ratio of 1.0, a reaction temperature of 90 °C, and a reaction time of 12 h. Full article
(This article belongs to the Special Issue Nanomineralogy)
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