Topical Collection "Clays and Other Industrial Mineral Materials"

A topical collection in Minerals (ISSN 2075-163X). This collection belongs to the section "Clays and Engineered Mineral Materials".

Editors

Prof. Dr. Manuel Pozo Rodríguez
E-Mail Website1 Website2
Collection Editor
Department of Geology and Geochemistry, Universidad Autónoma of Madrid, 28049 Madrid, Spain
Interests: geology and geochemistry of clays; special clays applications; sepiolite–palygorskite; bentonite; Talc–kerolite; clays and health; mineral characterization
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Prof. Dr. Francisco Franco
E-Mail Website
Collection Editor
Department of Inorganic Chemistry, Universidad de Malaga, 29071 Malaga, Spain
Interests: kaolin; smectite group of minerals; sepiolite; palygorskite; pelotherapy; advanced, clay-based materials; pharmaceutical uses of adsorption processes; new technologies
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Prof. Dr. Michael G. Stamatakis
E-Mail Website
Collection Editor
Department of Geology & Geoenvironment, National and Kapodistrian University of Athens (NKUA), 157 84 Athens, Greece
Interests: raw materials characterization; industrial minerals in environmental applications; economic geology; green geochemistry; mineralogy; cementitious and construction materials; industrial clays; fillers–filters–absorbents; microporous raw materials; marine aggregates; raw materials policy; mine waste reuse; environmental impacts; ecosystems; geoarchaeology; natural heritage
Special Issues, Collections and Topics in MDPI journals

Topical Collection Information

Dear Colleagues,

Industrial minerals form an exceptionally varied group of raw materials that cover virtually all needs of modern human life, although their presence is often invisible. Industrial minerals can be defined as those minerals that, due to their physical and/or chemical properties, are used in industrial processes. From a compositional point of view, industrial mineral materials include both silicates (e.g., zeolites and clays) and nonsilicates (e.g., chromite and barite). No doubt, it can be said that clay minerals and clays, whether in their natural state or modified, are outstanding materials in the field of industrial mineral materials. They are abundant, relatively cheap to obtain, and mostly friendly from an industrial and health viewpoint.

Clay is a textural term referring to natural rock, sediment, and/or alteration products mainly made up of very fine-grained clay mineral phyllosilicates. Clay minerals, whether natural or synthetic, show economically interesting physical and chemical properties directly related to their structure and composition. Both the layer charge and small particle size of the clay minerals give place to suitable properties such as plasticity, sorption, rheology, and ion exchange, among others.

Taking into account their origin, clay minerals can be detrital and authigenic. Detrital clay minerals are inherited and thus reflect the sediment source (provenance). Authigenic clay minerals are, in a broad sense, “formed or generated in place”, whether related to soil processes, sedimentary deposition or diagenesis; in addition, authigenic clays are also formed under low-grade metamorphic conditions and/or the influence of hydrothermal events.

When they are classified as industrial minerals, a distinction is made between common clays, which usually consist of an association of several clay minerals, and special clays, which are typically formed of just one clay mineral and include kaolin, bentonite, sepiolite and palygorskite.

This collection aims to cover several broad objectives. It will be focused mainly on the study of industrial clays and clay minerals, but it also will deal with other industrial minerals. Approaches to these industrial mineral materials can be focused on: 1) geology, 2) mineralogy and geochemistry, 3) mineral genesis, 4) physical and physicochemical properties, 5) industrial and environmental applications, and 6) methods for their characterization.

We look forward to your submissions.

Prof. Dr. Manuel Pozo Rodríguez
Prof. Dr. Francisco Franco
Prof. Dr. Michael G. Stamatakis
Collection Editors

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 submissions that pass pre-check are peer-reviewed. Accepted papers will be published continuously in the journal (as soon as accepted) and will be listed together on the collection 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 2000 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

  • Clays
  • Clay minerals
  • Industrial mineral materials
  • Geology
  • Mineralogy
  • Geochemistry
  • Genesis
  • Properties
  • Applications
  • Common clays
  • Special clays
  • Bentonite
  • Kaolin and related clays
  • Sepiolite
  • Palygorskite

Published Papers (4 papers)

2022

Jump to: 2021, 2020

Article
Coal Sludge Permeability Assessment Based on Rowe Cell Consolidation, and Filtration Investigations
Minerals 2022, 12(2), 212; https://doi.org/10.3390/min12020212 - 07 Feb 2022
Viewed by 413
Abstract
In this paper, an attempt has been made to investigate the possibility of using coal sludge to seal a landfill site by presenting the results of their compressibility and permeability tests. Coal sludge is a fine-grained waste from the coal enrichment process, and [...] Read more.
In this paper, an attempt has been made to investigate the possibility of using coal sludge to seal a landfill site by presenting the results of their compressibility and permeability tests. Coal sludge is a fine-grained waste from the coal enrichment process, and its permeability is also highly dependent on its degree of consolidation. The tests were carried out in a Rowe Cell, making it possible to determine the water permeability coefficient more precisely by determining the degree of the material consolidation during testing. The test was carried out using backpressure conditions. The test procedure in the Rowe Cell consisted of the following three steps: saturation, consolidation, and filtration. The coal sludge was taken directly from the filter presses as a by-product of the fines’ coal enrichment process. The paper presents the results of the individual stages performed in a Rowe Cell. The consolidation coefficient was determined using three different methods (Casagrande, Taylor, and Robbinson methods). The permeability coefficient was measured by the indirect and the direct method, the results of both were compared. The results (k < 10−9 m/s) indicated that the value of the permeability coefficient responds to the value for isolating barrier materials. Full article
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2021

Jump to: 2022, 2020

Article
A Novel Calcium Oxalate/Sepiolite Composite for Highly Selective Adsorption of Pb(II) from Aqueous Solutions
Minerals 2021, 11(6), 552; https://doi.org/10.3390/min11060552 - 23 May 2021
Cited by 3 | Viewed by 908
Abstract
Synthesizing functional nanomaterials from naturally abundant clay has always been of vital importance for resource utilization, however, the lack of new methods to effectively utilize low-grade clay presents a significant challenge. Herein, a calcium oxalate/sepiolite nanocomposite (SMN-x) was prepared by using the water [...] Read more.
Synthesizing functional nanomaterials from naturally abundant clay has always been of vital importance for resource utilization, however, the lack of new methods to effectively utilize low-grade clay presents a significant challenge. Herein, a calcium oxalate/sepiolite nanocomposite (SMN-x) was prepared by using the water bath heating method to convert the associated calcium carbonate in low-grade sepiolite into calcium oxalate. The developed composite was subsequently used to remove Pb(II) from the aqueous solutions. The SMN-3 adsorbent prepared by heating in a water bath at 90 °C for 3 h (with a high specific surface area of 234.14 m2·g−1) revealed the maximum Pb(II) adsorption capacity of 504.07 mg·g−1 at pH 5, which was about five times higher than that of sepiolite (105.57 mg·g−1). Further, the SMN-3 adsorbent possessed a much higher selectivity for Pb(II) as compared to the other metal ions. Moreover, the residue was noted to be stable and safe. The adsorption kinetics and isotherms conformed to the quasi-second-order kinetic and Langmuir models. During the adsorption process, ion exchange was noted to the main mechanism, however, it was also accompanied by electrostatic attraction. This study provides a novel strategy for the sustainable development of simple and efficient adsorbents by utilizing low-grade clay minerals. Full article
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2020

Jump to: 2022, 2021

Article
Sustainable Reuse of Coal Mine Waste: Experimental and Economic Assessments for Embankments and Pavement Layer Applications in Morocco
Minerals 2020, 10(10), 851; https://doi.org/10.3390/min10100851 - 26 Sep 2020
Cited by 9 | Viewed by 1734
Abstract
This paper deals with the potential reuse of coal mine waste rocks (CMWR) as an alternative material for road construction to conserve the natural resources and sustainable management of mining waste. The investigation was conducted through the determination of the chemical, mineralogical, geotechnical [...] Read more.
This paper deals with the potential reuse of coal mine waste rocks (CMWR) as an alternative material for road construction to conserve the natural resources and sustainable management of mining waste. The investigation was conducted through the determination of the chemical, mineralogical, geotechnical properties, and acid mine drainage formulation of CMWR as well as economic feasibility. This waste was used either alone for embankments and mixed with stabilizing agents fly ash (FA) and hydraulic road binder (HRB) for pavement applications. The experimental results confirmed that weathered CMWR can be successfully used alone as a sustainable alternative material for the embankment. Furthermore, the use of stabilizing agents in the following ratio CMWR:FA:HRB = 80:20:5 allow the use of CMWR in road sub-base layers for high-traffic pavements. Also, the environmental investigations showed that CMWR does not present any potential contaminating risk on the surrounding environment and most of the pyrite particles were already oxidized. Therefore, the environmental impact of acid mine drainage produced by pyritic waste throughout its life cycle can be neglected. Finally, an economic case study confirmed the workability of CMWR reuse in a radius of 29 km around their dumps by resulting in a lower cost compared with conventional materials. Full article
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Article
Application of Evolved Gas Analysis Technique for Speciation of Minor Minerals in Clays
Minerals 2020, 10(9), 824; https://doi.org/10.3390/min10090824 - 18 Sep 2020
Cited by 2 | Viewed by 1259
Abstract
Mineralogical characterization of clays used in manufacturing of traditional ceramic products is critical for guarantee the quality of the final product, but also for assessing the environmental impact of the industrial process in terms of atmospheric emissions. In fact, the presence of impurities [...] Read more.
Mineralogical characterization of clays used in manufacturing of traditional ceramic products is critical for guarantee the quality of the final product, but also for assessing the environmental impact of the industrial process in terms of atmospheric emissions. In fact, the presence of impurities even in low-level concentrations can have a big impact. So, it is very important to carry out an accurate mineral quantification of those minerals which are related to carbon dioxide and acid emissions (hydrogen fluoride, hydrogen chloride or sulfur dioxide). The development of hyphenated techniques coupling thermal analysis equipment with mass spectrometry and Fourier-transform infrared spectroscopy provides more valuable information and lower limit quantification than other primary techniques, such as X-ray diffraction or infrared spectroscopy. The main objective of this work is to develop an analytical procedure using evolved gas analysis to identify and quantify minerals such as chlorides, sulfides, carbonaceous materials and minor clay minerals. In addition to this, the study includes the analysis of acid emissions during the ceramic firing treatment even if they are present at low quantitative levels. This methodology was applied to reference materials so that it allows the identification of sulfur, chlorine, fluorine and carbonaceous compounds in concentrations lower than 1%. Full article
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