Special Issue "Mineral Surface Science and Nanogeoscience"

A special issue of Minerals (ISSN 2075-163X).

Deadline for manuscript submissions: closed (31 August 2016)

Special Issue Editor

Guest Editor
Dr. Athanasios Godelitsas

Faculty of Geology and Geoenvironment, School of Science, University of Athens, GR-15784, Athens, Greece
Website | E-Mail
Phone: +302107274689
Interests: mineral surface science and nanogeoscience; microporous/nanoporous minerals and rocks; environmental mineralogy and geochemistry; biomineralogy and medical geology; mineral atmospheric particles

Special Issue Information

Dear Colleagues,

In the last decades technological developments have revitalized a new area of research in Mineralogy with respect of the structure and reactivity of mineral surfaces. Mineral Surface Science is closely associated to the fields of Molecular Geochemistry and Biogeochemistry, concerning the investigation of geochemical processes at the molecular level. The expansion of both scientific subjects is based on the combined utilization of advanced microscopic and -surface- spectroscopic techniques, such as AFM, STM, TEM, SIMS, LIBS, and XPS. Nowadays, it is possible to study, by means of in situ AFM, crystal growth and dissolution processes occurring at mineral-fluid interfaces, in real time, also on a molecular scale (nanoscale). Moreover, accelerator-/Synchrotron-based techniques, including PIXE, NRRA, RBS, SR-(µ)XRF, SR-(µ)XRD and (µ)XANES/EXAFS, present new opportunities for Nanogeoscience and, in general, to Earth and Environmental Sciences. Mineral Surface Science and molecular Geochemistry have contributed to the establishment of Nanogeoscience with regard to the study of nanoparticles in nature and the investigation of geological processes in the nanoscale (1 nm–100 nm). As an example, a part of the research currently elaborated concerns the surface chemical behavior of calcite. This common carbonate mineral plays a major role in the global CO2 cycle, participates in key biomineralization processes, and shows high reactivity in fluids controlling the geoavailability and bioavailability of certain contaminants. On the other hand, nanoporous minerals, such as zeolites, clays, and Fe-Mn-oxides/oxyhydroxides, are important natural materials when studying the Earth and developing relevant Environmental Technology. Additionally, Mineral Surface Science and Nanogeoscience are crucial in ore systems research.

This Special Issue will focus on recent advances in Mineral Surface Science and Nanogeoscience, including, but not limited to, topics such as crystal growth; mineral dissolution; nanominerals; mineral nanoparticles; nanoporous minerals; nanoscale ore mineralogy; environmental mineralogy; environmental nanoparticles; atmospheric particles; biominerals; medical mineralogy; nanofossils; and nanoscopic methods.

Dr. Athanasios Godelitsas
Guest Editor

Manuscript Submission Information

Manuscripts should be submitted online at www.mdpi.com by registering and logging in to this website. Once you are registered, click here to go to the submission form. Manuscripts can be submitted until the deadline. All papers will be peer-reviewed. Accepted papers will be published continuously in the journal (as soon as accepted) and will be listed together on the special issue website. Research articles, review articles as well as short communications are invited. For planned papers, a title and short abstract (about 100 words) can be sent to the Editorial Office for announcement on this website.

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

  • mineral surfaces
  • nanogeoscience
  • crystal growth
  • mineral dissolution
  • nanominerals
  • mineral nanoparticles
  • nanoporous minerals
  • nanoscale ore mineralogy
  • environmental mineralogy
  • environmental nanoparticles
  • atmospheric particles
  • biominerals
  • medical mineralogy
  • nanofossils
  • nanoscopic methods

Published Papers (9 papers)

View options order results:
result details:
Displaying articles 1-9
Export citation of selected articles as:

Research

Open AccessArticle
Dissolution and Sorption Processes on the Surface of Calcite in the Presence of High Co2+ Concentration
Minerals 2017, 7(2), 23; https://doi.org/10.3390/min7020023
Received: 31 October 2016 / Revised: 26 January 2017 / Accepted: 10 February 2017 / Published: 15 February 2017
Cited by 2 | PDF Full-text (1439 KB) | HTML Full-text | XML Full-text
Abstract
The interaction of the calcite surface with Co2+-rich aqueous solutions ([Co2+aq]initial = 1000 ppm, i.e., ca. 17 mM) was investigated by means of macroscopic experiments and surface spectroscopic techniques. In the case of the macroscopic experiments, calcite [...] Read more.
The interaction of the calcite surface with Co2+-rich aqueous solutions ([Co2+aq]initial = 1000 ppm, i.e., ca. 17 mM) was investigated by means of macroscopic experiments and surface spectroscopic techniques. In the case of the macroscopic experiments, calcite powder and monocrystals were immersed into solutions for different time periods (from 1 min to one month). The Ca concentrations in the filtrates was measured by means of atomic absorption spectrometry (AAS) while the interacted solids were studied using a combination of X-ray photoelectron spectroscopy (XPS) and 12C-rutherford backscattering spectrometry (12C-RBS). The macroscopic data showed a characteristic surface dissolution process, in parallel to the surface sorption processes. Adsorption and co-precipitation were seen for almost the entire immersion period for both calcite powder and monocrystals. The surface study by XPS (analyzed at a depth of approximately 12 nm) suggested that adsorption takes place in the first hour of the interaction, followed by incorporation of Co2+ into calcite surface layers, leading to the formation of a Co2+-bearing surface (co)precipitate, which occurs over a period of hours and days. The 12C-RBS measurements on calcite { 10 1 ¯ 4 } indicated that the thickness of this surface co-precipitate was 270 nm after one day and then stabilized at 320 nm after more than a week. Full article
(This article belongs to the Special Issue Mineral Surface Science and Nanogeoscience)
Figures

Graphical abstract

Open AccessArticle
The Effect of Ca2+ and Mg2+ on the Dispersion and Flocculation Behaviors of Muscovite Particles
Minerals 2016, 6(3), 93; https://doi.org/10.3390/min6030093
Received: 20 May 2016 / Revised: 29 August 2016 / Accepted: 31 August 2016 / Published: 8 September 2016
Cited by 3 | PDF Full-text (1994 KB) | HTML Full-text | XML Full-text
Abstract
The dispersion and flocculation behavior of muscovite suspensions in the presence of Ca2+ and Mg2+ are relevant for industrial processing of pre-concentrated muscovite from stone coal, a primary source of vanadium. In this study, the dispersion and flocculation behavior were investigated [...] Read more.
The dispersion and flocculation behavior of muscovite suspensions in the presence of Ca2+ and Mg2+ are relevant for industrial processing of pre-concentrated muscovite from stone coal, a primary source of vanadium. In this study, the dispersion and flocculation behavior were investigated by means of sedimentation, zeta potential, and ion absorption experiments, as well as the force between particles and ion speciation calculations. The results indicated that the dispersion and flocculation behavior of muscovite particles without excess ions were in qualitative agreement with the classical DLVO theory. The muscovite particles aggregated mainly due to basal surface-edge interactions in acidic suspensions but were dispersed in alkaline suspension by electrostatic repulsion of the total particle surface. In acidic suspensions, the ability of muscovite to form dispersions of muscovite was increased with the decrease in the electrostatic attraction between the basal surface and the edge caused by the compression of the electric double layers withCa2+ and Mg2+. In alkaline suspension, the main adsorption form of Ca2+ and Mg2+ on muscovite surface was the ion-hydroxy complexes. The flocculation behavior of muscovite was affected by the static bridge effect of the ion-hydroxy complexes. Full article
(This article belongs to the Special Issue Mineral Surface Science and Nanogeoscience)
Figures

Graphical abstract

Open AccessArticle
The Effect of Chloride Ions on the Activity of Cerussite Surfaces
Minerals 2016, 6(3), 92; https://doi.org/10.3390/min6030092
Received: 16 July 2016 / Revised: 27 August 2016 / Accepted: 30 August 2016 / Published: 6 September 2016
Cited by 8 | PDF Full-text (2603 KB) | HTML Full-text | XML Full-text
Abstract
Chloride ions were found to potentially increase activity of cerussite surfaces. Dissolution experiments, zeta potential measurements, X-ray photoelectron spectroscopy (XPS) studies, and density functional theory (DFT) computation were conducted in this study. Dissolution experiments showed that the lead ion concentrations in the NaCl [...] Read more.
Chloride ions were found to potentially increase activity of cerussite surfaces. Dissolution experiments, zeta potential measurements, X-ray photoelectron spectroscopy (XPS) studies, and density functional theory (DFT) computation were conducted in this study. Dissolution experiments showed that the lead ion concentrations in the NaCl solution system were lower than those in the deionized water system and that the lead ion concentrations in NaCl + Na2S aqueous systems decreased by approximately one order of magnitude compared with that in the Na2S system alone. Results of zeta potential measurements revealed that the pretreatment with chloride ions of cerussite caused a more positive zeta potential than that without chloride ions. XPS analysis results indicated that the number of lead ions on the mineral surface increased after cerussite was treated with chloride ions. Results of DFT computation implied that the number of lead atoms on the mineral surface increased and that the activity improved after PbCl+ was adsorbed onto the cerussite surface. The contribution of chloride ions to the activity on the mineral surface is attributed to the increase in the number of active sites and enhancement in the activity of these sites, resulting in improved sulfidization and flotation performance. Full article
(This article belongs to the Special Issue Mineral Surface Science and Nanogeoscience)
Figures

Figure 1

Open AccessArticle
The Influence of Impurity Monovalent Cations Adsorption on Reconstructed Chalcopyrite (001)-S Surface in Leaching Process
Minerals 2016, 6(3), 89; https://doi.org/10.3390/min6030089
Received: 16 June 2016 / Revised: 14 August 2016 / Accepted: 18 August 2016 / Published: 29 August 2016
Cited by 4 | PDF Full-text (3369 KB) | HTML Full-text | XML Full-text
Abstract
Hydrometallurgical processing of chalcopyrite is hindered predominantly due to the passivation layers formed on the chalcopyrite surface. However, the effects of impurity cations released from the gangue are not yet well understood. Density functional theory (DFT) calculations were carried out to investigate monovalent [...] Read more.
Hydrometallurgical processing of chalcopyrite is hindered predominantly due to the passivation layers formed on the chalcopyrite surface. However, the effects of impurity cations released from the gangue are not yet well understood. Density functional theory (DFT) calculations were carried out to investigate monovalent cations of Na+ and K+ on chalcopyrite (001)-S surface using Materials Studio. The results show that the 3d orbital of Fe and 3p orbital of S predominantly contribute to their activities during chalcopyrite oxidation and dissolution processes. In addition, SO42− is more likely to be adsorbed on one Fe site in the presence of Na+, while it is preferentially adsorbed on two Fe sites in the presence of K+. However, the adsorption of both Na2SO4 and K2SO4 on the chalcopyrite (001)-S surface contributes to the breakage of S–S bonds, indicating that the impurity cations of Na+ and K+ are beneficial to chalcopyrite leaching in a sulfuric environment. The adsorption energy and partial density of states (PDOS) analyses further indicate that the adsorption of Na2SO4 on chalcopyrite (001)-S surface is favored in both -BB (bidentate binuclear ) and -BM (bidentate mononuclear) modes, compared to the adsorption of K2SO4. Full article
(This article belongs to the Special Issue Mineral Surface Science and Nanogeoscience)
Figures

Graphical abstract

Open AccessArticle
Restraining Na-Montmorillonite Delamination in Water by Adsorption of Sodium Dodecyl Sulfate or Octadecyl Trimethyl Ammonium Chloride on the Edges
Minerals 2016, 6(3), 87; https://doi.org/10.3390/min6030087
Received: 25 June 2016 / Revised: 1 August 2016 / Accepted: 18 August 2016 / Published: 23 August 2016
PDF Full-text (2346 KB) | HTML Full-text | XML Full-text
Abstract
The delamination of montmorillonite in water leads to sliming in ore slurry, which is detrimental to mineral flotation and solid/water separation. In this work, the delamination of Na-montmorillonite (Na-MMT) has been restrained by sodium dodecyl sulfate (SDS) or octadecyl trimethyl ammonium chloride (1831) [...] Read more.
The delamination of montmorillonite in water leads to sliming in ore slurry, which is detrimental to mineral flotation and solid/water separation. In this work, the delamination of Na-montmorillonite (Na-MMT) has been restrained by sodium dodecyl sulfate (SDS) or octadecyl trimethyl ammonium chloride (1831) through the adsorption on the edge of the mineral. The experimental results have shown that the pretreatment by adding SDS and 1831 could greatly reduce the Stokes size percentage of −1.1 µm particles in the aqueous Na-MMT suspension. From the X-ray diffractometer (XRD) results, the interlayer spacing of the MMT pre-treated by SDS and 1831 is smaller than that of original MMT particles. Adsorption position of SDS and 1831 on MMT surfaces was analyzed by the measurements of adsorption capacity of SDS and 1831, inductively-coupled plasma spectra, and zeta potential before and after the plane surface of MMT was covered with tetraethylenepentaminecopper ([Cu(tetren)]2+). The results indicated that SDS and 1831 are adsorbed on the edge and the whole surface of Na-MMT, respectively. Delamination of MMT could be well restrained by the adsorption of SDS and 1831 on the edges of MMT. Full article
(This article belongs to the Special Issue Mineral Surface Science and Nanogeoscience)
Figures

Figure 1

Open AccessArticle
Molecularly-Limited Fractal Surface Area of Mineral Powders
Minerals 2016, 6(2), 44; https://doi.org/10.3390/min6020044
Received: 24 February 2016 / Revised: 27 April 2016 / Accepted: 9 May 2016 / Published: 13 May 2016
PDF Full-text (2638 KB) | HTML Full-text | XML Full-text
Abstract
The topic of the specific surface area (SSA) of powders is not sufficiently described in the literature in spite of its nontrivial contribution to adsorption and dissolution processes. Fractal geometry provides a way to determine this parameter via relation SSA ~ x( [...] Read more.
The topic of the specific surface area (SSA) of powders is not sufficiently described in the literature in spite of its nontrivial contribution to adsorption and dissolution processes. Fractal geometry provides a way to determine this parameter via relation SSA ~ x(D − 3)s(2 − D), where x (m) is the particle size and s (m) is a scale. Such a relation respects nano-, micro-, or macro-topography on the surface. Within this theory, the fractal dimension 2 ≤ D < 3 and scale parameter s plays a significant role. The parameter D may be determined from BET or dissolution measurements on several samples, changing the powder particle sizes or sizes of adsorbate molecules. If the fractality of the surface is high, the SSA does not depend on the particle size distribution and vice versa. In this paper, the SSA parameter is analyzed from the point of view of adsorption and dissolution processes. In the case of adsorption, a new equation for the SSA, depending on the term (2 − D)∙(s2sBET)/sBET, is derived, where sBET and s2 are effective cross-sectional diameters for BET and new adsorbates. Determination of the SSA for the dissolution process appears to be very complicated, since the fractality of the surface may change in the process. Nevertheless, the presented equations have good application potential. Full article
(This article belongs to the Special Issue Mineral Surface Science and Nanogeoscience)
Figures

Figure 1

Open AccessArticle
Edge Structure of Montmorillonite from Atomistic Simulations
Minerals 2016, 6(2), 25; https://doi.org/10.3390/min6020025
Received: 23 February 2016 / Revised: 18 March 2016 / Accepted: 18 March 2016 / Published: 25 March 2016
Cited by 13 | PDF Full-text (3463 KB) | HTML Full-text | XML Full-text
Abstract
Classical molecular dynamics (MD) simulations have been performed to investigate the effects of substitutions in the octahedral sheet (Mg for Al) and layer charge on an atomistic model of the montmorillonite edge. The edge models considered substitutions in both the solvent accessible and [...] Read more.
Classical molecular dynamics (MD) simulations have been performed to investigate the effects of substitutions in the octahedral sheet (Mg for Al) and layer charge on an atomistic model of the montmorillonite edge. The edge models considered substitutions in both the solvent accessible and inaccessible octahedral positions of the edge bond chain for a representative edge surface. The MD simulations based on CLAYFF, a fully-flexible forcefield widely used in the MD simulations of bulk clay minerals, predicted Mg–O bond distances at the edge and in bulk that agreed with those of the density functional theory (DFT) geometry optimizations and available experimental data. The DFT results for the edge surfaces indicated that substitutions in the solvent inaccessible positions of the edge bond chain are energetically favorable and an increase in layer charge and local substitution density coincided with the occurrence of five-coordinate, square pyramidal Mg and Al edge structures. Both computational methods predicted these square pyramidal structures, which are stabilized by water bridging H-bonds between the unsaturated bridging oxygen [(Al or Mg)–O–Si] and other surface O atoms. The MD simulations predict that the presence of Mg substitutions in the edge bond chain results in increased disorder of the edge Al polyhedra relative to the unsubstituted edge. In addition to the square pyramidal Al, these disordered structures include trigonal bipyramidal and tetrahedral Al at the edge and inverted Si tetrahedra. These simulation results represent the first test of the fully-flexible CLAYFF forcefield for classical MD simulations of the Na-monmorillonite edge and demonstrate the potential of combined classical MD simulations and DFT geometry-optimizations to elucidate the edge structure of 2:1 phyllosilicate minerals. Full article
(This article belongs to the Special Issue Mineral Surface Science and Nanogeoscience)
Figures

Figure 1

Open AccessArticle
The Growth of Gypsum in the Presence of Hexavalent Chromium: A Multiscale Study
Minerals 2016, 6(1), 22; https://doi.org/10.3390/min6010022
Received: 12 January 2016 / Revised: 7 March 2016 / Accepted: 8 March 2016 / Published: 15 March 2016
Cited by 3 | PDF Full-text (5267 KB) | HTML Full-text | XML Full-text | Supplementary Files
Abstract
The sorption of dissolved inorganic pollutants into the structure of minerals is an important process that controls the mobility and fate of these pollutants in the Earth’s crust. It also modifies the surface structure and composition of the host mineral, affecting its crystallization [...] Read more.
The sorption of dissolved inorganic pollutants into the structure of minerals is an important process that controls the mobility and fate of these pollutants in the Earth’s crust. It also modifies the surface structure and composition of the host mineral, affecting its crystallization kinetics. Here, we investigate the effect of hexavalent chromium, Cr(VI), on the nucleation and growth of gypsum by conducting two types of experiments: (i) in situ atomic force microscopy (AFM) observations of the growth of gypsum {010} surfaces in the presence of Cr(VI) and (ii) gypsum precipitation experiments by mixing aqueous solutions containing variable amounts of Cr(VI). Gypsum precipitation is progressively delayed when occurring from solutions bearing increasing Cr(VI) concentrations. Chemical analyses of gypsum precipitates show that gypsum incorporates small Cr(VI) amounts that correlate with the content of this ion in the aqueous solution. Gypsum cell parameters variation reflects this incorporation. At the molecular scale, Cr(VI) induces a slowdown of step advance rates on gypsum {010} surfaces accompanied by the roughening of nanostep edges and the so-called “template effect”. This effect involves the reproduction of the original nanotopography after the completion of individual advancing monolayers and appears as a general nanoscale phenomenon occurring during growth of solid solutions from aqueous solutions even in the case of compositionally-restricted solid solutions. Full article
(This article belongs to the Special Issue Mineral Surface Science and Nanogeoscience)
Figures

Figure 1

Open AccessArticle
Ab initio Studies of O2 Adsorption on (110) Nickel-Rich Pentlandite (Fe4Ni5S8) Mineral Surface
Minerals 2015, 5(4), 665-678; https://doi.org/10.3390/min5040516
Received: 9 June 2015 / Revised: 29 July 2015 / Accepted: 30 July 2015 / Published: 12 October 2015
Cited by 6 | PDF Full-text (7115 KB) | HTML Full-text | XML Full-text
Abstract
Ab initio density functional theory was used to investigate the adsorption of oxygen molecule on the nickel-rich pentlandite (110) surface, which is important for mineral extraction. The three most reactive adsorption sites: Fe-top, Ni-top, and fcc-hollow have been considered. Firstly, the non-adsorbed pentlandite [...] Read more.
Ab initio density functional theory was used to investigate the adsorption of oxygen molecule on the nickel-rich pentlandite (110) surface, which is important for mineral extraction. The three most reactive adsorption sites: Fe-top, Ni-top, and fcc-hollow have been considered. Firstly, the non-adsorbed pentlandite surface reflects the Ni atoms relaxing inwards. Consequently, their electronic structure showed high Fe 3d-orbital contribution than the Ni 3d-orbitals at the EF (indicating that the Fe atoms are more reactive than Ni). Secondly, the O2-adsorbed surface predicted lowest adsorption energy for Fe-top (-1.902 eV), as a more spontaneous reaction is likely to occur than on fcc-hollow (-1.891 eV) and Ni-top (-0.040 eV) sites, suggesting Fe preferential oxidation. The density of states indicates that the O2 show prevalence of electrons in the πp* antibonding orbitals, and are reduced to zero states at the valence band on metal-bonded oxygen (O1). The πp* orbital is observed to reside just above the EF for Fe-top and fcc-hollow site, while on Ni-top is half-occupied for both metal-bonded oxygen (O1) and terminal oxygen (O2). Finally, the isosurface charge density difference showed electron (charge) depletion on Ni/Fe metals and accumulation on the O2 molecule. Bader analysis indicated that the oxidized Fe and Ni atoms adopt more positive charge, while O2 on Fe-top atoms possesses more negative charge than on Ni-top, resulting with O1 possessing a smaller charge than O2 atom. Full article
(This article belongs to the Special Issue Mineral Surface Science and Nanogeoscience)
Figures

Figure 1

Minerals EISSN 2075-163X Published by MDPI AG, Basel, Switzerland RSS E-Mail Table of Contents Alert
Back to Top