Effect Of Clay Type Research Articles

Effects of clay type and component fineness on the hydration and properties of limestone calcined clay cement

Effects of clay type and component fineness on the hydration and properties of limestone calcined clay cement

The Effect of Clay Type, Fineness and Methylene Blue Value on Mini-Slump Performance of Cementitious Systems

The Effect of Clay Type, Fineness and Methylene Blue Value on Mini-Slump Performance of Cementitious Systems

Investigating the effect of clay content and type on the mechanical performance of calcium alginate-based hybrid bio-capsules

This study aims to investigate the mechanical behavior of alginate-based simple and alginate@clay-based hybrid capsules under uniaxial compression using a Brookfield force machine. The effect of clay type and content on Young's modulus and nominal rupture stress of the capsules was investigated and characterized using Scanning Electron Microscopy (SEM), and Fourier Transform Infrared Spectroscopy (ATR-FTIR). Results showed that clay content improves the mechanical properties depending on its type. Montmorillonite and laponite clays showed optimal results at 3 wt% content, with a gain of 63.2 % and 70.34 % on Young's modulus, and a gain of 92.43 % and 108.66 % on nominal rupture stress, respectively, while kaolinite clay showed optimal results at 1.5 wt% content with an increase of 77.21 % on Young's modulus and 88.34 % on nominal rupture stress. However, exceeding the optimal content led to decrease the elasticity and rigidity due to the incomplete dispersion of clay particles in the hydrogel network. The theoretical modeling using Boltzmann superposition principle revealed that the elastic modulus was in good agreement with experimental values. Overall, this research provides insights into the mechanical behavior of alginate@clay-based capsules, which could have potential applications in drug delivery systems and tissue engineering.

Pore-scale modelling on complex-conductivity responses of hydrate-bearing clayey sediments: Implications for evaluating hydrate saturation and clay content

A majority of the accumulated gas hydrates exist in fine-grained unconsolidated sediments with clays, which pose challenges to reservoir evaluation with resistivity-based techniques. Characteristic electrical parameters derived from induced polarization (IP) measurements have potentials to describe complex formations of various lithology, pore-water salinities, and different depths from the borehole. However, there is still a knowledge gap in complex-conductivity properties of the hydrate-bearing clayey sediments. We present a pore-scale numerical study on modelling the low-frequency (<1 kHz) complex-conductivity spectra of clayey sediments containing hydrates based on the finite-element approach, with an emphasis on evaluating the hydrate saturation (sh) and clay content. Firstly, the influences of clay type, distribution form, content and sh on the complex conductivity of sediments containing hydrates were examined systematically. Secondly, power-law and linear correlations were established for evaluating the hydrate saturation and clay content, respectively, based on complex-conductivity parameters. (Effects of clay type) The in-phase conductivity of hydrate-bearing smectite is significantly higher than that of hydrate-bearing illite and kaolinite due to the higher cation exchange capacity (CEC) of smectite. Higher peak frequency and quadrature conductivity appear for the hydrate-bearing kaolinite case because the mobility of counterions in the Stern layer of kaolinite is about ten times of that for smectite and illite. (Effects of clay distribution form) The coating-clay case has much lower in-phase and quadrature conductivities than the dispersed- and laminated-clay cases because the coating clay isolates sand particles from the pore water and no electrical double layer (EDL) forms around the sand particles. (Effects of clay content) With an increasing content of the structural clay up to 60%, the in-phase conductivity decreases and increases in the frequency bands lower and higher, respectively, than the peak frequency corresponding to the EDL polarization. The effective dielectric constant increases consistently with the clay content due to the much higher CEC of clays than that of sands. (Effects of hydrate saturation) The in-phase conductivity decreases consistently with an increasing sh up to 0.40 due to the negligible conductivity of hydrates and blockage effect on conduction currents. Both the quadrature conductivity and effective dielectric constant in the EDL-polarization-dominant frequency band decrease with an increasing sh. In this work, it has been evidenced that complex-conductivity responses of hydrate-bearing clayey sediments can be understood theoretically and modelled numerically based on the interpretation of electrical conduction and electrochemical polarization mechanisms of EDLs. This study provides a theoretical and modelling foundation for the development of new IP-based geophysical techniques for hydrate-reservoir evaluation and monitoring in both the exploration and exploitation stages.

The effect of clay type and solid wettability on bitumen extraction from Canadian oil sands

Clays (<2 μm) in oil sands ores have a significant impact on the processability of the ores. The present study aims at understanding the effects of the type and wettability of clays on the performance of bitumen extraction from mined oil sands. The results from batch extraction tests showed a detrimental effect of doping with hydrophilic clays (kaolinite, illite and montmorillonite), with montmorillonite being the worst. The crucial role of clays in bitumen slime-coating was studied through atomic force microscopy and clay deposition tests. For the hydrophilic clays, clay concentration was an essential parameter in determining the bitumen-clay hetero-coagulation process. Strong slime-coating of clay particles on bitumen droplets occurred only above a critical clay concentration. This critical concentration varied with clay type and water chemistry. Compared with earlier studies, kaolinite was found to deposit strongly on bitumen surfaces for the first time in this study. Hydrophilic clays were contaminated by soaking in toluene-diluted-bitumen solutions to investigate the effect of solid hydrophobicity on bitumen extraction. Hydrophobic clays had a less significant depression on bitumen recovery but a more significant deterioration on froth quality than hydrophilic clays. Similar slime-coating was observed for the different clays once contaminated by diluted bitumen. Furthermore, the presence of a large content of clays in bitumen extraction could result in excessive emulsification of bitumen into small droplets, leading to low bitumen recovery. This work provides useful insights into the fundamental interactions of clays and bitumen, with implications for developing a viable solution in dealing with clays in oil sands operations.

Effect of clay type and content on the mechanical properties of clayey silt hydrate sediments

Knowledge of the mechanical properties of natural gas hydrate reservoirs is fundamental to the safe and commercial extraction of natural gas hydrate. In our work, according to the characteristics of marine sediments in the South China Sea, gas hydrate samples with matrices containing 0%, 10%, 20%, and 30% montmorillonite or illite were prepared based on the saturated gas method. Under effective confining pressures of 2, 3 and 4 MPa, drained compression tests were performed on the samples. The results show that the clay type and clay content affect the failure strength and deformation of clayey silt hydrate sediments. The presence of clay causes the clayey silt hydrate samples to exhibit strain hardening behavior accompanied by shear shrinkage, and the failure strength and stiffness decrease with increasing clay content, as does the internal friction angle. The strength, stiffness, and Poisson's ratio of samples containing illite are generally greater than those containing montmorillonite. In addition, due to the strong bound water between particles, the cohesion of hydrate samples containing montmorillonite with similar hydrate saturations is higher than that of samples containing illite, while the internal friction angle is lower. These results are valuable for production well siting assessment in clayey silt hydrate reservoir and provide requisite theoretical basis for wellbore safety design.

Development and characterization of alginate@montmorillonite hybrid microcapsules for encapsulation and controlled release of quercetin: Effect of clay type

In the present study, different organic and hybrid systems for quercetin (Qr) encapsulation were developed, namely Ca-Alginate (Qr-Alg), Ca-Alginate@Na-montmorillonite (Qr-Alg@Na-Mnt), and Ca-Alginate@CPC-montmorillonite (Qr-Alg@CPC-Mnt).Attenuated total reflecting-Fourier-transform infrared (ATR-FTIR) analysis was used to characterize and prove quercetin encapsulation in the developed microcapsules. The encapsulation efficiency (EE) and loading capacity (LC) of quercetin in elaborated biomaterials were determined. Besides, the release kinetics of quercetin molecules from organic and hybrid microcapsules were carefully investigated in two different aqueous mediums; pure distilled water and distilled water containing Tween 20 (1%, w/v).The obtained results show that all developed microcapsules have a good encapsulation efficiency and loading capacity within the range 97.65 ± 0.57–99.47 ± 0.38% for the EE and 19.26 ± 0.46–23.29 ± 0.82 mg/g for the LC. The release rates of Qr from organic microcapsules Qr-Alg, hybrid microcapsules Qr-Alg@Na-Mnt, and Qr-Alg@CPC-Mnt in distilled water containing Tween 20 (1%, w/v) are 52, 49, and 113 times bigger, respectively, than release rate in distilled water.In addition, the kinetics release from hybrid microcapsules was slower in comparison to organic microcapsules. Also, in the case of hybrid microcapsules, the rate of kinetic release of quercetin from Qr-Alg@Na-Mnt was greater than the one from Qr-Alg@CPC-Mnt. This is due to the strong interactions of quercetin molecules with nanoparticle functional groups of cetylpyridinium chloride modified montmorillonite organoclay (CPC-Mnt) compared to sodium montmorillonite (Na-Mnt). The kinetics of Quercetin release from all developed organic and hybrid microcapsules follows the Korsmeyer–Peppas model and is controlled by non-Fickian diffusion.

Effect of Clay Type on Emulsion Formation in Steam and Solvent Steamflooding

SummaryThe objectives of this study are to perform a fundamental analysis of the mutual interactions between crude oil components, water, hydrocarbon solvents, and clays, and to determine the optimum hydrocarbon solvent in solvent steamflooding for a particular reservoir type. The water/oil emulsion formation mechanism in the obtained oil for steam and solvent steamflooding processes has been studied via intermolecular associations between asphaltenes, water, and migrated clay particles. A series of 21 steam and solvent-steamflooding experiments has been conducted, first without any clays in the oil/sand packing, and then using two different clay types in the reservoir rock: Clay 1, which is kaolinite, and Clay 2, which is a mixture of kaolinite and illite. Paraffinic (propane, n-butane, n-pentane, n-hexane, n-heptane) and aromatic (toluene) solvents are coinjected with steam. Cumulative oil recovery is found to decrease in the following order: no clay, Clay 1, Clay 2. Based on the obtained produced oil analyses, Clay 1 and Clay 2 are found to have an affinity with the water and oil phases, respectively. Moreover, the biwettable nature of Clay 2 makes it dispersed in the oil phase toward the oil/water interface, stabilizing the water/oil emulsions. Paraffinic solvent n-hexane is found to be an optimum coinjector for solvent steamflooding in bitumen recovery.

Preparation and characterization of polyethylene/cellulose composite with diatomite and bentonite as fillers

ABSTRACTThis research work was carried out to examine the performance of different polyethylene/cellulose composites. The effect of three different factors was examined. First factor was the effect of clay type as filler, in which diatomite and bentonite were used. Second factor was the effect of cellulose grafting with cyclic oxymethylene. Third factor was the presence of polyethylene grafted with maleic anhydride (PE-g-MA) in the polymer matrix of polyethylene/cellulose as a compatibilizer. The polymer matrix was characterized by scanning electron microscope (SEM), differential scanning calorimetry (DSC) and thermal gravimetric analysis (TGA). Tensile test and permeability were also examined.

An investigation of the effect of clay type on coal flotation along with DLVO theoretical analyses

ABSTRACTCoals generally exist with clay minerals, which are very fine-sized minerals, and adversely affect the flotation of coal. For instance, they make the coal surface hydrophilic by coating coal surfaces and therefore, they inhibit bubble-particle attachment. Clay minerals can also cause over-consumption of reagents due to their high surface area. Additionally, clay minerals can transfer into the concentrate during the flotation process by entrainment because of their low weight and small particle size, and thus, increase pulp viscosity and changing froth stability. In this study, the influence of various clay minerals (kaolinite, illite, and bentonite) on the flotation behavior of coal sample was studied in detail by conventional flotation tests. In addition, the values obtained from flotation tests were correlated with theoretical energy barrier values established with classical DLVO theory based on zeta potential values of coal and clay samples measured at different pH values. According to the results of this study, no significant effect of clay minerals was observed on coal flotation. This was probably because of the high floatability of the coal used for this study. Both the results obtained from the experiments and theoretical analysis, DLVO calculations, showed that the type of clay mineral is the main indicator parameter for coal flotation.

Effect of clay type on the properties of hybrid latexes of poly(vinyl acetate) and montmorillonite prepared via surfactant-free emulsion polymerization

Effect of clay type on the properties of hybrid latexes of poly(vinyl acetate) and montmorillonite prepared via surfactant-free emulsion polymerization

Molecular Simulation Study on Methane Adsorption Capacity and Mechanism in Clay Minerals: Effect of Clay Type, Pressure, and Water Saturation in Shales

The methane adsorption behaviors and mechanism in clay minerals are investigated by molecular dynamics and grand canonical Monte Carlo simulation methods. Simulation models of montmorillonite, chlo...

The Effect of Clay Type On the Properties of Cohesive Sediment Gravity Flows and Their Deposits

The present knowledge of cohesive clay-laden sediment gravity flows (SGFs) and their deposits is limited, despite clay being one of the most abundant sediment types on earth and subaqueous SGFs transporting large volumes of sediment into the ocean. Lock-exchange experiments were conducted to contrast SGFs laden with noncohesive silica flour, weakly cohesive kaolinite, and strongly cohesive bentonite in terms of flow behavior, head velocity, runout distance, and deposit geometry across a wide range of suspended-sediment concentrations.

Effects of exchangeable cations, mineralogy and clay content on the mineralization of plant residue carbon

Interactions of clay minerals with organic materials and the consequences of these interactions on dynamics of organic carbon (OC) have been reviewed in detail. However, the effects of exchangeable cations and clay types on the turnover rate of OC have not been given much attention. Appropriate amounts of homoionic Na-, Ca- and Al-clays from Georgia kaolinite, Illinois illite and Wyoming bentonite were mixed with pure sand to prepare artificial soils with different clay contents, exchange cations and clay types. Alfalfa plant residues were incorporated into the artificial soils and the soils were inoculated with microbes from a natural soil and incubated for 184days to study the effects of clay contents, exchangeable cations and clay types on the mineralization of OC and plant residue derived microbial biomass. Mineralization of plant residue carbon was significantly (⁎⁎p<0.01) more rapid in pure sand than in soils containing 5 and 10% clay, indicating that clay contents influence the capacity of soils to protect and store OC. The amounts of biomass carbon were lowest in pure sand and highest in soils with 10% clay. There was a significant influence (⁎⁎p<0.01) of exchangeable cations on microbial biomass and hence the mineralization of OC over a period of 184days. At 5 and 10% clay contents, the amounts of microbial biomass carbon and the mineralization of plant residue carbon were highest in Ca-soils and lowest in Al-soils. Statistical analysis of data showed a significant effect (⁎⁎p<0.01) of clay type on mineralization of plant residue carbon and microbial biomass. However, the effects of clay types on the mineralization of OC were much less than those of clay contents and exchangeable cations. The mineralization of plant residue carbon was highest in soils with Georgia kaolinite clay and lowest in soils with Wyoming bentonite clay. The amounts of biomass carbon were slightly lower in soils with Wyoming bentonite clay than soils with Georgia kaolinite and Illinois illite clay minerals. The results of this study indicate that OC and microbial biomass are stabilized in soils through the interaction with clay minerals and a small amount of clay (5%) slows OC decomposition significantly and reduces carbon dioxide emission from soils. Exchangeable cations exert their influence on microbial biomass and hence carbon dynamics by controlling the size and activity of the microbial population through modifying the physicochemical characteristics of microbial habitats.

Synthesis of organo-montmorillonite and its effect on soil urease and L-glutaminase activites

Organoclays are highly important to environmental studies due to their unique applications. The amidohydrolase family plays a significant role in maintaining a sustainable environment and agriculture sector. Therefore, keeping these enzymes active and stable in soil is a crucial task. In doing so, this study focused on the synthesis of organo-montmorillonite (MMT) and its effect on activity and stability of these enzymes in soil. The organo-MMT was synthesized by modifying the Na-MMT using the HDTMA-Br Cationic surfactant. Mineralogical properties of the synthesized organoclay were analyzed using X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR) and field emission scanning electron microscope (FESEM) instruments. The effects of this organoclay and incubation period on urease and L-glutaminase activities in soil were also investigated. Results showed that the d-spacing of organo-MMT was increased by adding surfactant. Results from statistical analyses showed that the effect of clay type and incubation period on the activity of both enzymes (urease and L-glutaminase) were significant at the 5% level. The activity of both enzymes in the soil samples treated with the organo-MMT was significantly higher than control and MMT samples. The organoclay prepared successfully maintained soil enzymes. Therefore, use of this organoclay can positively affect enzyme activity and stability. This study plays an important role in synthesizing low-cost organoclays to be used in increasing the stability and activity of amidohydrolase family in soil.

Microbial degradation of diesel oil and heavy oil in the presence of modified clay

ABSTRACT The effects of clay type, microbial quantity, and inoculation time on the microbial degradation of 0# diesel oil and 180# heavy oil were studied. The results showed that the surfactant-modified clay had a significant promotion effect on the degradation of oil. The removal efficiencies of diesel oil and heavy oil after 7 days were up to 87% and 95%. The optimum conditions were determined and the oil biodegradation was in accordance with the first-order kinetics. All the results obtained can provide experimental basis for oil microbial degradation.

Effects of clay minerals on diethyl phthalate degradation in Fenton reactions

Phthalate esters are a group of plasticizers, which are commonly detected in China's soils and surface water. Fenton reactions are naturally occurring and widely applied in the degradation of contaminants. However, limited research was considered the effects of clay minerals on contaminants degradation with OH oxidation. In this study, batch experiments were conducted to investigate the degradation of diethyl phthalate (DEP) in Fenton reactions in the presence of clay minerals, and the effects of clay type, Fe content in clay structure. The results showed the clay adsorption inhibited total degradation of DEP, and Fe content in clay structure played an important role in DEP degradation, including in solution and adsorbed in clay minerals. Clay minerals with less Fe content (<3%) quenched OH radical, while nontronite with Fe content 19.2% improved OH radical generation and accelerated DEP degradation in solution. The degradation of clay-adsorbed DEP was much slower than DEP in solution. Six main products of DEP degradation were identified, including monoethyl phthalate, phthalate acid, hydroxyl diethyl phthalate, etc. This study implied that phthalate ester's degradation would be much slower in natural water than expected in the presence of clay minerals.

Isothermal crystallization of polycaprolactone/modified clay biodegradable nanocomposites

In this paper, the isothermal crystallization of polycaprolactone (PCL)/modified clay nanocomposites, at several temperatures, was studied. The effects of clay type (organo-modified bentonite B-TBHP and organo-modified montmorillonite C20A) and also the clay content were analysed. Bulk crystallization was studied by differential scanning calorimetry and modelled by the Avrami equation. Special effort was made to correlate the crystallization parameters with the clay dispersion degree inside the polymer matrix. The lowest induction time and fastest overall crystallization rate were obtained with the B-TBHP nanocomposites, which showed the lowest clay dispersion degree. In contrast, C20A nanocomposites showed higher clay dispersion degree inside the PCL matrix and higher induction times and lower overall crystallization rate than B-TBHP ones, even retarding the formation of the equilibrium nucleus with critical dimensions in comparison with neat PCL.

Effect of clay type on dispersion and barrier properties of hydrophobically modified poly(vinyl alcohol)–bentonite nanocomposites

ABSTRACTThe oxygen and water vapor permeability at high relative humidity was studied for composite films formed by incorporation of three different bentonites (MMT) into an ethylene‐modified, water‐soluble poly(vinyl alcohol), EPVOH. The oxygen permeability decreased linearly with an increased addition of hydrophilic MMTs. X‐ray diffraction and Fourier transform infrared spectroscopy suggested a homogeneous distribution in the thickness direction with disordered and probably exfoliated structures for hydrophilic MMTs. In contrast, organophilic modified clay showed an intercalated structure with the clay preferentially located at the lower film surface, a combination which was however efficient in reducing the water vapor‐ and oxygen permeabilities at low addition levels. Composite films of EPVOH and Na+‐exchanged MMT resulted in high resistance to dissolution in water, which was ascribed to strong interactions between the components resulting from matching polarities. Annealing the films at 120°C resulted in enhanced resistance to water dissolution and a further reduction in oxygen permeability. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 42229.

The effect of clay type and dispersion conditions on electroosmotic consolidation behaviour of model kaolinite and Na-exchanged smectite pulps

Effective dewatering and disposal of mineral waste tailings continue to be important issues for the minerals industry globally. Conventional hydrometallurgical processes involving low grade ores produce voluminous amounts of dilute dispersions, fine particles and equivalently large volumes of intractable waste tailings of low solid density. For tailings rich in clay minerals, conventional flocculant-mediated gravity sedimentation (thickening) used for dewatering achieves fast settling rates but poor sediment consolidation, even after several years of dam impoundment. Hence cost-effective methods that achieve compact pulp consolidation and enhanced process water recycling are warranted.In the present work, batch electroosmotic (EO) consolidation behaviour of single and binary mixtures of model kaolinite and two types of Na-exchanged smectite pulps was investigated. Specifically the influence of clay type, ionic strength, pulp interfacial chemistry (particle zeta potential) and swelling behaviour on efficacy of EO was assessed. EO consolidation of pre-sedimented pulps at pH 7.5 was effective for kaolinite and a low-Na exchanged smectite whose interfacial chemistry was altered and swelling behaviour suppressed via Ca(II) ions addition. EO consolidation achieved 10–15wt.% solid increases, resulting in ‘spadeable’ pulps at acceptable power consumption rates. No such significant improvement was achieved for the high-Na exchanged smectite, contrary to expectation.