Types Of Clay Minerals Research Articles

Characterization of clays from the Corumbataí formation used as raw material for ceramic industry in the Santa Gertrudes district, São Paulo, Brazil

The Ceramic District of Santa Gertrudes (CDSG) is the largest producer of ceramic floor and wall tiles in Brazil. Tile manufacturers in the CDSG use the single raw material, clayey rocks from the Corumbataí formation. Mineralogical, chemical, thermal and microstructural characterization of the clayey rocks from the Corumbataí formation have been performed in order to better understand effect of the studied properties on dry route tilemaking process. The results revealed different compositional features among the studied clayey raw materials. The bulk samples were dominated by clay minerals associated with quartz, feldspars and minor amount of hematite. All samples were complex mixtures where different types of clay minerals (illite, smectite, illite–smectite, kaolinite–smectite, chlorite, sometimes kaolinite) coexist in variable amount. The amount of clay minerals increased with a higher degree of weathering of studied samples. Different technological behavior was expected for studied raw materials due to their heterogeneous nature, in terms of mineral composition and weathering degree. To improve technological behavior of studied materials during tilemaking process an upgrade of the currently used raw materials preparation is recommended (raw materials maturation, more aggressive milling of raw materials, addition of plastic component and homogeneous mixing of plastic and non-plastic components).

Microstructure of Unburned Clay and its Shrinkage during Drying

Unburned clay was used for the traditional engineering works for thousands years. Its qualities have not been too appreciated in the last few decades. Because of that, its material characteristics were never researched very rigorously. In last years, we could see increasing demand for use of this building material in building practice and research. The basic problem that should be mitigated by civil engineers handling unburned clay is its considerable shrinkage during drying. The degree of shrinkage depends on the amount of mixture water and on the amount and type of clay minerals. In the unburned clay, like in the cement, clay minerals play role of the binder. The problem is that clay minerals are causing volume changes. This paper is focused on the degree of shrinkage and its dependence on the species and quantity of clay mineral.

Clay Mineralogy of Coal-Hosted Nb-Zr-REE-Ga Mineralized Beds from Late Permian Strata, Eastern Yunnan, SW China: Implications for Paleotemperature and Origin of the Micro-Quartz

The clay mineralogy of pyroclastic Nb(Ta)-Zr(Hf)-REE-Ga mineralization in Late Permian coal-bearing strata from eastern Yunnan Province; southwest China was investigated in this study. Samples from XW and LK drill holes in this area were analyzed using XRD (X-ray diffraction) and SEM (scanning electronic microscope). Results show that clay minerals in the Nb-Zr-REE-Ga mineralized samples are composed of mixed layer illite/smectite (I/S); kaolinite and berthierine. I/S is the major component among the clay assemblages. The source volcanic ashes controlled the modes of occurrence of the clay minerals. Volcanic ash-originated kaolinite and berthierine occur as vermicular and angular particles, respectively. I/S is confined to the matrix and is derived from illitization of smectite which was derived from the original volcanic ashes. Other types of clay minerals including I/S and berthierine precipitated from hydrothermal solutions were found within plant cells; and coexisting with angular berthierine and vermicular kaolinite. Inferred from the fact that most of the I/S is R1 ordered with one case of the R3 I/S; the paleo-diagenetic temperature could be up to 180 °C but mostly 100–160 °C. The micro-crystalline quartz grains (<10 µm) closely associated with I/S were observed under SEM and were most likely the product of desiliconization during illitization of smectite.

Highly thermal stable organoclays of ionic liquids and silane organic modifiers and effect of montmorillonite source

Since many polymer–organoclays nanocomposites are prepared in melt state, the thermal stability of the surfactants present in these organoclays is extremely important. Alkyl ammonium salts are surfactants which have been used in organoclays, but the low thermal degradation temperature of these salts is a drawback for polymer nanocomposites preparation in the melt state at temperatures higher than 200 °C. In order to obtain organoclays more suitable to be used in these polymer nanocomposites, in this work clay minerals were modified with more thermally stable organic modifiers than conventional salts. Two types of commercial clay minerals were organically modified with alkyl ammonium salt, alkyl and aryl phosphonium salts and an organosilane compound. X-ray diffraction, thermogravimetric analysis (TG) and infrared analysis results indicate that for both commercial clay minerals the preparation of the organoclays was efficient. TG analysis confirmed that phosphonium and silane organoclays are more thermally stable as compared with conventional alkyl ammonium organoclays. It was also observed that the thermal resistance of the organoclay depends on the type of the aluminosilicate used for the organic modification.

Assessment of heavy metal enrichment in the offshore fine-grained sediments of the Caspian Sea.

Sampling of the offshore seabed sediments of southwestern part of the Caspian Sea was carried out by gravity corer in order to study heavy metal concentration and the physicochemical factors controlling their distribution in the fine-grained fraction. The grain size distribution, amount, and type of clay minerals, total organic carbon (TOC) content, and Eh-pH of the sediments were determined. The average concentrations of the heavy metals in ppm are Mn (563), Cu (207.5), Sr (187), Zn (94), Pb (26.3), Ni (14.5), Co (11.5), Cd (2.56), and Ag (1.04) in their order of abundances. Co and Zn mostly indicate increase in silt-size fraction of the sediments suggesting their probable detrital provenance but the Mn, Ni, Cu, Sr, Pb, Cd, and Ag concentrations show a similar trend to distribution of the clay-size fraction. The concentrations of Mn, Co, and Cd increase with increase in the TOC content but the Cu, Pb, Ni, Ag, and Sr concentrations decrease with increase of the TOC content. The amounts of Zn, Cu, Sr, Pb, Cd, and Ag increase with increase in the CaCO3 content. The calculated enrichment factor indicates that the sediments are very strong to extremely enriched in Ag, significantly enriched in Cu and Cd, and depleted to mineral for Pb, Sr, Co, Ni, and Zn. Variations of the Cu, Sr, Cd, Ag, and Pb concentrations are similar to the clay and CaCO3 distributions.

Paleosol and dolocrete associated clay mineral occurrences in siliciclastic red sediments of the Late Miocene Kömişini Formation of the Tuzgölü basin in central Turkey

The Late Miocene was characterized by high global temperatures and partly to nearly complete desiccation of the Mediterranean Sea throughout the latter part of the Messinian age (the Messinian salinity crisis). The Late Miocene marine Mediterranean Sea area has been widely studied from different perspectives, but terrestrial paleoenvironmental and paleoclimatic records from the Mediterranean area are highly limited in their spatial range. To this end, the paleosols, dolocrete and fluvial sedimentary rocks of the Kömişini Formation in the northwestern part of the Tuzgölü basin are described in detail. Six lithofacies were identified as (A) clast-supported gravel, (B) massive (pebbly) sandstone, (C) massive mudstone, (D) disrupted mud, (E) disrupted conglomerate, and (F) disrupted matrix-supported conglomerate. The siliciclastic facies were interpreted as braidplain, and the distal part of braidplain deposits is associated with an ophiolitic area while the disrupted mud and disrupted conglomerate were identified as three types of paleosols: Inceptisols, Aridisol and Vertisols. The calcretes occur in the paleosols in nodular, powder, and massive forms. Clay minerals include smectite, chlorite, palygorskite, illite, and serpentine. Gypsum, smectite and chlorite are dominant minerals at the base and middle part of the section, whereas palygorskite and illite appear as the prevailing clay minerals in the upper sections. Smectite, illite and palygorskite precipitated in a vadose zone from strongly evaporated alkaline water rich in Si, Ca and Mg and poor in Al at increased temperatures and at an advanced stage of dolocrete and paleosol formation. K, Si, Mg, Al+Fe and Ca are required for smectite, illite, palygorskite and calcification. Given the increase in Ba, Cr, Ni and Co, these cations might have originated from ophiolite, carbonate and volcanic units. As a consequence, the vertical distribution of clay mineral types suggests the variations of paleoclimatic conditions during the deposition, and the relationships among the type of host rock, paleosol and dolocrete, which corresponds to nearly complete desiccation of the Mediterranean Sea.

The Effect of Treated Municipal Wastewater and Fresh Water on Saturated Hydraulic Conductivity of a Clay-Loamy Soil

The effect of irrigating with treated municipal wastewater (TMW) and fresh water (FW) on saturated hydraulic conductivity (Ks) was investigated. Ks was determined in undisturbed soil samples, collected from the upper soil layer (0–15 cm) of an illitic clay-loamy soil, after two irrigation periods. Soil samples were analyzed for a number of factors potentially affecting Ks. Analysis of variance for each of these factors was performed between the two treatments in order to detect their differences. Statistically significant differences were found for pH, ECe, SAR, ESP and the concentrations of K+, Na+, Mg2+ which are elements related with TMW and FW quality-characteristics. Correlation between all factors and Ks showed that this was positive for soil ECe, CaCO3 and negative for SAR, ESP, and bulk density. Although the influence of each separate factor was investigated and the differences between the two treatments were verified, their quantitative characteristics could not explain based on existing criteria, (the Ks reduction observed between the TMW-Ks and FW-Ks). The 2:1 type clay minerals which are more susceptible to SAR increase and EC decrease affected Ks values between the two treatments. Our findings are in line with some recently reported results and in this sense, more specific research is needed to clarify all aspects relevant to Ks and the use of TMW for irrigation purposes.

Investigation of expansive soils in Obhor Sabkha, Jeddah-Saudi Arabia

Expansion or swelling of soil is a worldwide geotechnical problem that occurs in arid and semiarid regions where sabkha soils may occur as well. Expansive soil is dominated by the presence of active clay minerals. The expansive and sabkha soils are characterized by a large seasonal variation in soil moisture content leading to a large change in the volume and the consistency of the soil and, thus, causing serious damages to buildings and infrastructure. Although sabkha soil covers large and strategically important areas along the Red Sea and Arabian Gulf coasts in Saudi Arabia, no one paid proper attention to the type of clay minerals in those soils or to their expansion potential, which is a crucial step prior to any construction. The geotechnical properties, active clay mineral types, and the degree expansion potential of soils were investigated in Obhor area at the north of Jeddah City. Twenty disturbed soil samples were collected at depths of 80 and 120 cm. Three different types of soils are identified: clayey soil with high plasticity, clayey soil with low plasticity, and poorly graded silty to clayey sand soil. Furthermore, active clay minerals were identified with a significant proportion of montmorillonite (14.24 %), illite (24.65 %), kaolinite (28.78 %), and chlorite (32.34 %). The results indicated that a considerable part of the study area has high expansion potential, but most parts of Obhor area have low to none potential of soil expansiveness.

Preparation and characterization of non-solvent halloysite nanotubes nanofluids

In this paper, a novel type of clay mineral (halloysite) nanofluids was successfully synthesized through surface hydroxylated treatment and then tertiary amine and sulfonate anions. The halloysite (Hal) exhibits liquid-like behavior in the absence of solvent above 80°C while it is a gel-like stickum at room temperature. Moreover, the morphology, rheological behavior, thermal and dispersion properties of the resultant Hal nanofluids were systematically characterized by Fourier transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD), energy dispersive X-ray (EDX) analysis, X-ray photoelectron spectroscopy (XPS), transmission electron microscopy (TEM), thermogravimetric analysis (TGA), UV–Vis transmission spectra and rheological test. Rheological test results show that viscoelasticity (solid-like to liquid-like transition) of Hal nanofluids were regulated by temperature variation. The unique properties of the Hal nanofluids have made this material promising in the applications as rheological additives in industrial paints and polymer processing aids fields.

Development of volume reduction method of cesium contaminated soil with magnetic separation

In this study, we developed a new volume reduction technique for cesium contaminated soil by magnetic separation. Cs in soil is mainly adsorbed on clay which is the smallest particle constituent in the soil, especially on paramagnetic 2:1 type clay minerals which strongly adsorb and fix Cs. Thus selective separation of 2:1 type clay with a superconducting magnet could enable to reduce the volume of Cs contaminated soil. The 2:1 type clay particles exist in various particle sizes in the soil, which leads that magnetic force and Cs adsorption quantity depend on their particle size. Accordingly, we examined magnetic separation conditions for efficient separation of 2:1 type clay considering their particle size distribution. First, the separation rate of 2:1 type clay for each particle size was calculated by particle trajectory simulation, because magnetic separation rate largely depends on the objective size. According to the calculation, 73 and 89 % of 2:1 type clay could be separated at 2 and 7 T, respectively. Moreover we calculated dose reduction rate on the basis of the result of particle trajectory simulation. It was indicated that 17 and 51 % of dose reduction would be possible at 2 and 7 T, respectively. The difference of dose reduction rate at 2 T and 7 T was found to be separated a fine particle. It was shown that magnetic separation considering particle size distribution would contribute to the volume reduction of contaminated soil.

X-ray Absorption Fine Structure at the Cesium L3 Absorption Edge for Cesium Sorbed in Clay Minerals

We present the use of near-edge X-ray absorption fine structure (NEXAFS) to investigate local electronic structures of cesium ions sorbed in two types of clay minerals (vermiculite and kaolinite) with a different capacity to fix Cs. NEXAFS is element-specific because X-ray absorption edges of different elements have different energies. However, the energy of the Cs L3 absorption edge is close to that of the K-edge of titanium generally contained in clay minerals. Therefore, Cs L3-edge NEXAFS measurements of Cs in clay minerals have not yet succeeded. In this study, we confirmed the peak intensity between vermiculite and kaolinite in the Cs L3-edge NEXAFS spectra by separately monitoring T Kα and Cs Lα fluorescence X-rays. To clarify the identification of NEXAFS spectra, theoretical calculations were performed using the discrete variational Xα molecular orbital method (DV-Xα), and peak identification was achieved. The difference in peak intensity was explained by the difference in the electron density of u...

Confined water in tunnel nanopores of sepiolite: Insights from molecular simulations

Sepiolite is a type of magnesium-rich fibrous clay mineral. The unique fibrous structure endows it with various applications in many fields. Revealing the behavior of confined water in sepiolite nanopores is crucial to understand the macroscopic properties of sepiolite. Aiming to ascertain the distribution and dynamics of the confined water, molecular simulations using grand canonical Monte Carlo and molecular dynamics methods have been performed. We obtain the water adsorption isotherm, density distribution profiles, and dynamic information of the confined waters in sepiolite tunnels. We find that zeolitic water is very hard to be desorbed from sepiolite under ambient conditions. Based on the distribution profile and trajectories of the water, we reveal the accurate distribution sites and propose a new distribution model of the confined water including one bound water site and four zeolitic water sites, which are determined by sepiolite lattice. The zeolitic water at different sites can exchange freely and frequently, and thus these sites may be energetically similar. This model provides more fundamental understanding of the hydration of sepiolite, and highlights the water behaviors in the tunnel pores of microporous minerals, which are thought being controlled by the crystallographic structure. The much lower mobility of zeolitic water in sepiolite than that in montmorillonite implies that materials with nano-sized tunnel pores could have more efficient fixation on foreign molecules or ions in environmental applications than those layered materials with slit pores.

Quantification and key factors in delamination of (Mg1 − yNiy)1 − xAlx(OH)2(NO3)x·mH2O

Dispersions of delaminated layered double hydroxides (LDH) contain nanosheets of interest for single particle studies and for preparation of different types of clay mineral-clay mineral or clay mineral–polymer nanocomposites and coatings. Reproducible methods were currently benchmarked, key parameters influencing the degree of delamination were identified, and prerequisites for achieving high yield delamination routes evaluated. Inert synthesis, screening by turbidity measurements and gravimetric quantification allowed identification of how various parameters influence delamination. For (Mg1−yNiy)1−xAlx(OH)2(NO3)x·mH2O preparative parameters as hydrothermal treatment, drying conditions and pH during synthesis have significant impact on delamination abilities. Poorly delaminating Ni0.75Al0.25(OH)2(NO3)0.25·mH2O LDH is by adequate hydrothermal treatment converted to a material that undergoes almost complete delamination. The adopted procedures allow systematic studies on how preparative parameters as well as more chemical parameters such as interlayer chemistry and cationic composition in the brucite like layers interacts with solvent properties. Improved insight into parameters controlling delamination properties open up for routes on large scale manufacturing of clay mineral-clay mineral nanocomposites requested for novel types of catalysts. Particles, dispersions and nanosheets were characterized by ICP-OES, CN-analysis, turbidity, XRD, TEM, SAXS, AFM and XPS measurements.

Evaluation of the stress sensitivity in tight reservoirs

Abstract The expressions of three types of stress sensitivity coefficients ( S, α, β ) are obtained on the basis of analysis of the empirical models and theoretical models on the relationships between permeability and effective stress, and the stress sensitivity evaluation standard is proposed considering experiment data and rock micro-structural features. Then the empirical models and theoretical models were used to fit experiment data of low-permeability and tight sandstones and different types of granites, which promotes the understanding of the empirical models and the physical meanings of the stress sensitivity coefficients. According to the study of the three types of stress sensitivity coefficients and the relationship of effective stress and permeability, it is found that the stress sensitive coefficient S is suitable for evaluating the stress sensitivity (strong stress sensitivity: S >0.40; low stress sensitivity: S S ≤0.4). Meanwhile, it is also found that strong-stress-sensitivity cores are more suitable to be characterized by the logarithmic model, while the exponential model (or binomial model) occurred more frequently in low-stress-sensitivity cores, and medium-stress-sensitivity cores are more likely to be described with the power model. Finally, the evaluation standard is discussed based on the micro-structure in the low-permeability and tight sandstones. The results show that the crack-like pores in the strong-stress-sensitivity cores are obvious, but low-stress-sensitivity cores have the characteristics of porous rocks; moreover, the types of cemented clay minerals, the size of rock grain and lithology have impact on stress sensitivity.

The effect of microstructure and rock mineralogy on water imbibition characteristics in tight reservoirs

Published studies have suggested that the spontaneous imbibition induced by the high capillary force of tight rocks is a significant mechanism responsible for low flowback efficiency (<30%). However, due to the complex pore structure and mineral composition, the imbibition characteristic is complicated and requires further investigation. In this paper, comparative imbibition experiments were conducted on 12 core samples from different tight formations. The authors investigate the water imbibition characteristics of tight rocks with different mineralogy, pore connectivity and pore-size distribution. The results show that three key parameters of practical application value (i.e., the initial imbibition rate, late imbibition rate and imbibition capacity) can be used to present the imbibition characteristics. The water imbibition capacity is partially dependent on the clay mineral content and type, as shown by the positive correlation between imbibition capacity and total clay content, especially the amount of smectite and illite/smectite mixed-layer clay. In addition, the behaviors of imbibition curves vary greatly in the different tight rocks, which could be, at least in part, controlled by the pore size distribution and pore connectivity. To a large extent, well-developed macropores tend to have good pore connectivity and large time exponents at the initial imbibition region, and well-developed mesopores and micropores tend to have poor pore connectivity and large time exponents at the late imbibition region.

Surface Wettability of Basal Surfaces of Clay Minerals: Insights from Molecular Dynamics Simulation

Understanding the wettability of clay mineral surfaces is crucial for enhancing oil recovery, investigating primary migration of hydrocarbon, and evaluating the performance of sealing rocks in a petroleum system. On the basis of molecular dynamics simulations, we investigated the interactions between four typical clay minerals (i.e., pyrophyllite, montmorillonite, illite, and kaolinite) and confined pore fluids (i.e., water/alkane/salts). The influences of surface group, layer charge, and salts on the wettability of clay surfaces were revealed. As the layer charge increases, the hydrophilicity of the montmorillonite basal surface gradually increases. The basal surface of 2:1-type pyrophyllite is completely alkane-wet independent of salts. However, for 1:1-type kaolinite, the presence of salts makes the siloxane surface completely water-wet, whereas it is partially alkane-wet at the absence of salts. In general, the salt ions adsorbed onto clay surfaces promote the surface hydrophilicity. By using nonequil...

Sensitivity study on thermal behavior and kinetics of crude oil using thermal analysis techniques

ABSTRACTIn this study, the effect of heating rate, oil chemical composition, and clay mineral type on thermokinetic behaviors of oil oxidation was investigated by TG and DTA tests. The results show that temperature intervals of reactions are extended and peak and burnout temperatures are shifted to higher values when increasing the heating rate. Heavier oil with more heavy components exhibits faster reaction rate and higher energy requirement in the low-temperature oxidation stage, and releases more heat in the high-temperature oxidation stage. The catalytic properties and surface area effect of clays can positively influence the high-pressure air injection process through forming more carbonaceous deposits and lowering the activation energy of reactions.

Water-Sensitivity Characteristics of Briquettes Made from High-Rank Coal

In order to study the water sensitivity characteristics of the coalbed methane (CBM) reservoir in the southern Qinshui Basin, the scanning electron microscopy, mineral composition and the water sensitivity of main coalbed 3 cores were tested and analyzed. Because CBM reservoirs in this area are characterized by low porosity and low permeability, the common water sensitivity experiment of cores can’t be used, instead, the briquettes were chose for the test to analysis the water sensitivity of CBM reservoirs. Results show that: the degree of water sensitivity in the study area varies from week to moderate. The controlling factors of water sensitivity are clay mineral content and the occurrence type of clay minerals, permeability and liquid flow rate. The water sensitivity damage rate is positively correlated with clay mineral content and liquid flow rate, and is negatively correlated with core permeability. The water sensitivity of CBM reservoir exist two damage mechanisms, including static permeability decline caused by clay mineral hydration dilatation and dynamic permeability decline caused by dispersion/migration of clay minerals.

English

Kaolin is one of several types of clay minerals. The most common crystalline phase constituting kaolin minerals is kaolinite, with the chemical composition Al 2 Si 2 O 5 (OH) 4 . Kaolin is mostly used for manufacturing traditional ceramics and also to synthesize zeolites or molecular sieves. The Si-O and Al-O structures in kaolin are inactive and inert, so activation by calcination is required. This work studies the conversion of kaolin originating from Bangka island in Indonesia into calcined kaolin phase as precursor in NaY zeolite synthesis. In the calcination process, the kaolinite undergoes phase transformations from metakaolin to mullite. The Bangka kaolin is 74.3% crystalline, predominantly composed of kaolinite, and 25.7% amorphous, with an SiO 2 /Al 2 O 3 mass ratio of 1.64. Thermal characterization using simultaneous DSC/TGA identified an endothermic peak at 527°C and an exothermic peak at 1013°C. Thus, three calcination temperatures (700, 1013, and 1050 °C) were selected to produce calcined kaolins with different phase distributions. The best product, with 87.8% NaY zeolite in the 54.7% crystalline product and an SiO 2 /Al 2 O 3 molar ratio of 5.35, was obtained through hydrothermal synthesis using mixed calcined kaolins with a composition of K 700C : K 1013C : K 1050C = 10 : 85 : 5 in %-mass, with seed addition, at a temperature of 93 °Cand a reaction time of 15 hours.

DFT theoretical and FT-IR spectroscopic investigations of the plasticity of clay minerals dispersions

Plasticity is the most important property of dispersions of clay minerals that determine the character of participation of these systems in many natural and technological processes. We report on the results of studies of hydration mechanism in typical clay minerals making part of natural dispersions of sedimentation masses by means of IR spectroscopy and theoretical density functional theory (DFT) methods. X-ray diffraction analysis of clay minerals of Millerovo mineral deposit (Russian Federation) is carried out. Regularities and peculiarities of interaction of water molecules with kaolinite basal planes (001) and (001¯) are analyzed. The role of water in the formation of plasticity of clay minerals dispersions is revealed. The modes of water molecules placement and their state and structure in the system “clay mineral-water” is defined. Phase transition processes of clay minerals dispersion into plastic and liquid state and their influence on spectral characteristics of the systems are investigated. The interpretation of clay minerals phase transitions into plastic and fluid state based on the results of DFT simulation is given. The relation is established between specific variation of spectral characteristics and phase transitions of clay minerals dispersions into plastic and liquid state.