Egyptian Clay Research Articles

Heterogeneous nanocomposite catalysts supported on activated Egyptian clay for biofuel production from castor oil

Heterogeneous nanocomposite catalysts supported on activated Egyptian clay for biofuel production from castor oil

Implications for Geochemistry of the Egyptian Clay Deposits and their Suitability for the Vitrified Clay Pipes Industry

Implications for Geochemistry of the Egyptian Clay Deposits and their Suitability for the Vitrified Clay Pipes Industry

Enhancing the properties of lightweight aggregates using volcanic rock additive materials

The aim of the research was to investigate the applicability of different volcanic rocks as additives materials in lightweight aggregates (LWA) production. This study explains how the high amorphous content can improve the bloating properties of expandable clays and the properties of the LWAs produced. Ten different expandable clays, suitable for lightweight aggregate production, were collected and tested from clay deposits in Egypt and Hungary. Perlite and rhyolite tuff were used as volcanic rock aggregates. The composition of the samples was investigated by X-ray fluorescence spectroscopy (XRF) and X-ray powder diffraction (XRD, Rietveld method), while their expandability was characterized by heating microscopy (HM). The ideal amount of volcanic rock additives (10 wt%) and the required firing temperatures (1225 °C for the Hungarian clays and 1275 °C for the Egyptian clays) were determined and the LWAs were then produced. The LWAs produced (by hand rolling) by mixing of 90 wt% of expandable clay with 10 wt% of the additive materials (10 wt% perlite or 10 wt% rhyolite tuff) as green pellets then fired for different temperature. The LWAs made by mixing 10 wt% perlite or 10 wt% rhyolite tuff were characterized by their density, compressive strength, mineral composition, and pore structure. All samples had a density of less than 1.2 g/cm3, so they can be used as LWA. The results show that the additives helped some clay samples produce LWA with higher strength but lower density than the reference sample which was used, enabling the construction of lighter but stronger structures. Compositional analysis of the LWAs showed that there is a strong correlation between the amorphous content of the samples and their density, with higher amorphous content resulting in lower density.

Adsorption performance of coated bentonite via graphene oxide

BackgroundThe nano-adsorbents present considerable decontamination potential due to their unique characteristics. This study aimed to investigate the adsorption efficiency and capacity of synthesized nano graphene oxide coated layer over Egyptian clays (bentonite, kaolinite and feldspar) as substrate. The experimental work involves nano graphene oxide coating using acid dehydration via sulfuric acid in presence of different percentage of sugar (fine powder from 1 to 7%), followed by thermal activation to improve the adsorption capacity of natural clay that is locally available in Egypt. Several operating parameters were studied to prepare the superior adsorbent (type of substrate, sulfuric acid concentration, sugar concentration and contact time).ResultsThe optimum preparation conditions of nano graphene oxide coated bentonite (NGOCB) adsorbent were bentonite substrate 1 kg, sulfuric acid concentration 1.5 kg/kg clay, sugar fine powder 50 g/kg clay, water 3000 ml/kg clay, and stirring time of 30 min at 100 °C. The morphology characterization showed that the deposited graphene oxide layer is in the nano form (6 to 33 nm). Sets of experiments were conducted to evaluate the adsorption performance of synthesized NGOCB for removal of methylene blue (MB) dye from aqueous solutions. Effect of initial dye concentration, contact time, pH and temperature on the adsorption capacity of the modified adsorbent were studied. The capacity of the prepared nano graphene oxide coated bentonite adsorbent was 1000 mg/g.ConclusionsThe removal efficiency of nano graphene coated clay reached to 99.9% that indicates the Egyptian bentonite could be employed as a low-cost absorbent for dye removal.

ГЛИНЯНЫЕ СВЕТИЛЬНИКИ ИЗ ГРЕКО-РИМСКОГО МЕМФИСА

The article explores 15 terracotta oil lamps found during the archaeological excavations of the Centre for Egyptological Studies of the Russian Academy of Sciences at Kom Tuman (Memphis, Egypt). The majority of these lamps were made in moulds, and only one — on potter’s wheel. Various types of local Egyptian clays were used for the production of the lamps. Many of the lamps are decorated with various ornaments, such as palms, dolphins, torches, and, possibly, the ‘Macedonian shield’. Similar lamps were widespread in all the territory of Egypt; equally, such lamps appear among archaeological finds in the countries neighbouring with Egypt. The Memphite lamps under study were found in mixed layers and, therefore, we have compared them with analogous lamps from other locations in order to obtain more secure dating. Based on the parallels, we date the lamps to the Ptolemaic and Roman Periods (3rd century B.C. — 3rd century A.D.). The archaeological context of the lamps indicates their possible use in households and/or in temples for illumination of indoor spaces. The lamps are archaeological evidence for the existence of active everyday life at Kom Tuman in Graeco-Roman Period which is also confirmed by other sources. The study of archaeological pottery and of papyri found in the city of Memphis and in adjacent necropoleis shows that even after the foundation of the new Ptolemaic capital Alexandria, Memphis was not abandoned but continued for centuries to be a major administrative and cultic centre. The article includes the catalogue of 15 lamps with descriptions and illustrations.

Melamine-Ceramic Membrane for Oily Wastewater Treatment

Four distinctive Ceramic membranes have been synthesized using bentonite and Egyptian clay with the expansion of melamine. The addition of melamine (~ 1% by wt.) enhanced the porosity, density, the thermal stability and water permeability of the membranes made from bentonite or Egyptian clay while decreasing the chemical stability of either bentonite or Egyptian clay membranes. The most noteworthy level of decrease in COD (94.7%) is acquired for the concentration of 200ppm with saturating flux of 4.63 E-05 (m3/m2.s) utilizing (B+M) membrane. The cost of the four manufactured clay membranes was assessed based on raw materials used in the present investigation.

Modification of Egyptian clay by different organic cations

Nowadays, clay minerals are used extensively in a wide range of applications as nano additives for polymeric materials. Nevertheless hydrophilic characteristics of the nano additives reduce their degree of compatibility with polymeric chains. To overcome this problem it is necessary to modify the clay in order to render its surface more organophilic prior to the intercalation of the polymeric chains between its layers. In this work the Egyptian natural clay mineral montmorillonite (MMT) was modified with two cationic organic modifiers, namely hexadecyltrimethylammonium (HDTMA) and tributyl hexadecyl phosphonium using two different procedures. The first, using the magnetic stirrer while the second using a high speed mixer at different mixing times from 0.5 up to 2.5 hr. The samples with and without organic modifiers were characterized by X-ray diffraction (XRD), infrared spectroscopy (IR), thermogravimetric analysis (TGA), scanning electron microscope (SEM) and transmission electron microscope (TEM). XRD results revealed that the basal spacing of the organo-montmorillonite (OMMT) prepared using high speed mixer was larger than that using magenetic stirrer. The best result was obtained after 1.5 hr stirring in the high speed mixer. The modification of MMT was confirmed by FTIR as determined from –CH2 stretching vibration of the organic modifiers. The TGA analysis revealed that the MMT modified with tributyl hexadecyl phosphonium cation had high thermal stability than that modified with hexadecyl trimethyl ammonium cation. The amount of surfactants within organoclays were found to be found to be about 19 and 24%, respectively, for hexadecyl trimethyl ammonium bromide and tributyl hexadecyl phosphonium bromide. SEM demonstrated that the modified MMT exhibited a massive thin layered structure with some large flacks and some interlayer spaces. TEM images of the prepared organoclays showed exfoliated structure. This work proved to enhance the economical value of the Egyptian natural resources.

Tracing the provenance of unfired ancient Egyptian clay figurines from Saqqara through non-destructive X-ray fluorescence spectrometry

A collection of Prime Cultural Heritage artefacts consisting of Egyptian late Middle Kingdom figurines (c. 1850–1700 BCE), made of unfired clay and covered in inscriptions, is kept at the Royal Museums of Art and History (RMAH) in Brussels, Belgium. Several of these hieratic inscriptions curse enemies of the Egyptian state, including Canaanite, Nubian and Libyan entities; thus providing invaluable information for Middle Bronze topography in ancient Near Eastern studies. What makes the extensive Brussels group even more exceptional, is the fact that these figurines were discovered in a closed archaeological context in Saqqara, Lower Egypt. Defining and classifying clay and ancient ceramic provenance groups in Egypt is highly complex due to variability in Nile and marl clay deposits. Chemical characterization of this figurine assemblage (n = 91) allows to effectively study the potential direct use of clays in the vicinity of Saqqara and characterize the nature of the raw materials used. Additionally, it aims to assess the validity of portable XRF spectrometry for this type of materials and its provenance resolution. Analyses show that very similar clays were used to produce the different morphological types of figurines in the assemblage. The chemical profile indicates the use of a mixed source at Saqqara rather than pure marl or Nile clays, which are common for ancient pottery production.

Technological properties of high alumina refractories with different phosphoric acid contents

BackgroundHigh alumina refractory batches were prepared from Egyptian clay and imported China calcined bauxite. Three concentrations of phosphoric acid 3, 5, and 7%, were added to study their effects on some of their technological properties. Designed batches tend to form a composition of 76% alumina and ~ 17% silica in addition to the other fluxing and alkali oxides. Chemical and mineralogical composition as well as density and plasticity of both clay and calcined bauxite was performed.ResultsThree batches of different phosphoric acid concentrations were fired at 1350 °C for 1 h. Densification parameters of the fired batches as well as the cold crushing strength and thermal shock resistance were carried out. The mineral composition and microstructure of the selected batch were done using XRD as well as SEM and EDAX. It is concluded that by increasing phosphoric acid percentages, the porosities slightly increase and the cold crushing strengths drastically decrease; however, densities and shrinkages exhibit no remarked effects.ConclusionsThe mineral composition of the selected fired batch exhibits mullite as a main phase with subordinate amount of corundum, while berlinite, quartz, and cristobalite are in less frequent contents. Microstructure of the selected batch ensures that mullite and corundum are the main mineral phases, in addition to minor phases of phosphate minerals. The fluxing and alkali oxides together with some alumina and silica form a liquid phase, which is responsible for the densification of the batch, while mullite and corundum are the essential formed minerals.

Insights on the role of organic matters of some Egyptian clays in methyl orange adsorption: Isotherm and kinetic studies

The role of organic matters (OM) of some Egyptian clay in Methyl Orange (MO) adsorption from aqueous solutions was tested for the first time. To elaborate this role, the raw Organic Matters-Rich Clays (OMRC) was calcinated at 500 °C/4 h to remove their associated OM by oxidation. Then the MO removal efficiency by both OMRC and its calcinated derivative (COMRC) was tested at different experimental parameters. The adsorption of MO by the studied adsorbents was pH- and time-dependent process and the equilibrium was attained after 60 min. The pseudo-second-order model with high determination coefficients (R2 > 0.999) fitted well the adsorption kinetics, while the intra-particle diffusion was not the rate governing step in MO adsorption by both adsorbents. The MO adsorption characteristics revealed that equilibrium data of OMRC and COMRC fitted well to the Freundlich and Langmuir models, respectively. Electrostatic interaction was the primary but not the only governing mechanism for MO adsorption by the investigated adsorbents; participation from hydrogen bonding mechanism was involved, with some preference for COMRC. The superiority of OMRC over COMRC in MO adsorption can be attributed to the involvement of oxygen- and nitrogen-bearing groups of both OM and clay minerals in the adsorption process on the contrary of COMRC in which only oxygen-bearing groups of the clay minerals were incorporated.

Effect of salinity of groundwater on the geotechnical properties of some Egyptian clay

This study deals with the effect of salinity of groundwater on some properties of clayey soil. Properties obtained from tests carried out on samples mixed with water containing different salt contents are compared with those obtained from tests carried out on samples mixed with pure water (tap water). The tested samples were taken from the site of the Faculty of Engineering in Qena, South Valley University. Two sets of samples of the clay soil were tested. One was mixed with pure water (pure water clay soil) and the other was mixed with salty water added to it in ratios ranging from 20% to 80% (clay soil mixed with salt). The test results showed the effect of groundwater salinity on the tested samples. The plasticity index decreased from 26 for pure water clay soil to 24.96 for clay soil mixed with 80% salt. The coefficient of consolidation increased from 0.00196 for pure water clay soil to 0.002744 for clay soil mixed with 80% salt. The California bearing ratio increased from 9.75% for pure water clay soil to 10.15% for clay soil mixed with 80% salt. The optimum moisture content increased from 14.25% for pure water clay soil to 16.5% for clay soil mixed with 100% salt. Decrease in the maximum dry density is observed for clay soil mixed with salty when compared with pure water clay soil. A marked decrease was noticed for the value of the unconfined compressive strength. All the tests were carried out in the Soil Mechanics and Foundations Lab, Faculty of Engineering in Qena, South Valley University.

Effect of Silica Fume Addition and Firing Temperature on Physico-Mechanical Properties of Clay Bricks

The aim of this research is to study the additive effect of fumed silica waste on some physical and mechanical properties of clay bricks. Ts perform that, five batches of Egyptian clay and fumed silica were designed with fumed silica ratio 0, 2, 4, 6 and 8 mass-%, shaped into a cylinder mould and fired at 800°C, 900°C and 1000°C. The chemical and mineral composition of the raw materials was carried out using XRF and XRD as well as SEM and EDAX, respectively. Phase composition, physical and mechanical properties of fired batched were investigated to evaluate the changes occurred as a result of fumed silica addition and firing. We concluded that addition of fumed silica leads to; reduce density, shrinkage and compressive strength, while the water absorption and porosity increased. The rising of the firing temperature leads to increase density and compressive strength as well as the linear shrinkage, while reducing the porosity and water absorption. All samples have sufficient strength values greater than 20 MPa. These results confirm that the brick samples produced from fumed silica addition with clay with different ratio could be used as a construction material.

Structural Characteristics of the Egyptian Clay as a Low-Cost Adsorbent

A study of the characteristics of clay from El-Sheikh Fadl Village, El-Minia governorate in Egypt has been carried out. A crucial factor in the applying clay as a low-cost adsorbent, however, is the understanding of the physical, chemical, mineralogical, and colloidal properties of these clays. The characteristics of texture such as surface area, pore volume, porosity, pore size distribution, particle shape and density were determined. The pore size distribution results showed that natural clay is predominantly mesoporous. The thermal behavior of clay was studied using differential thermal analysis and thermogravimetric analysis analysis. The X-Ray diffraction analysis was performed in order to determine the main constituents of the materials. The X-Ray diffraction analysis verified the presence of kaolinite, montmorillonite and quartz in the natural clay. Then clay was tested for infrared spectra, it confirm the presence of the constituents mentioned above. The structure and chemical composition, exchangeable ion type and small crystal size of montmorillonite are responsible for several properties, including a large chemically active surface area.

Engineering properties of cement/lime-stabilized Egyptian soft clay

Soft clay formations are extensively located in many coastal areas around the world. The significant high compressibility and low shear strength of these formations impose challenging engineering problems. The deep cement/lime-mix-in-place method is one of the ground improvement techniques exhibiting successful use in stabilizing soft clay. Analysis and design of the deep mixing systems necessitate the identification of the additive content, the proportions of the lime to cement and the characteristics of the stabilized clay. This paper investigates experimentally the influence of adding lime and cement or cement alone, as stabilizing additives, on the engineering behavior of an Egyptian soft clay extracted from the north delta region. A series of laboratory tests were carried out considering, different additive contents of 8, 10, 12, and 14% of the dry weight, with different proportions of lime to cement of 50:50, 25:75 and 0:100. A series of unconfined compression strength tests were performed after different periods; one week, four weeks and 8 weeks, to assess the effect of curing period on the stabilized clay response. In addition, one dimensional consolidation tests were carried out to evaluate the compressibility properties of the stabilized clay. This study declared that the use of an additive content in the range of 12% and more is recommended to improve the characteristics of the considered Egyptian clay. It was pointed out that addition of lime and cement to soft clay significantly increases the strength characteristics and significantly reduces the compressibility characteristics of such clay.

Inhibition of cadmium- induced genotoxicity and histopathological changes in Nile tilapia fish by Egyptian and Tunisian montmorillonite clay

Cadmium (Cd) is an important inorganic toxicant widely distributed in the environment because of its various industrial uses. The aims of the current study were to investigate the efficacy of purified Egyptian and Tunisian montmorillonite clays (EMC and TMC) to inhibit genotoxicity and histological alterations induced by cadmium chloride (CdCl2) utilizing the Nile tilapia fish as an in vivo model. Chromosomal aberrations (CAs), micronucleus (MN) frequencies and DNA fingerprinting profile were genotoxic end points and histopathological changes that were used in this investigation. Six groups of fish were treated for 2 weeks and included control group, CdCl2-treated group and groups treated with EMC or TMC alone or in combination with CdCl2.The present results revealed that, treatment of fish with CdCl2 exhibited significant increased in the number of micronucleated erythrocytes (MnRBCs), frequency of CAs and instability of genomic DNA. Treatment of EMC and TMC in combination with CdCl2 significantly reduced the frequency of MnRBCs by the percentage of 53.28% and 60.77% and the frequency of CAs by 43.91% and 52.17% respectively. As well as, normalized DNA fingerprinting profile and significantly improved histopathological picture induced by Cadmium treatment. It is worth mention that both clays have the ability to tightly bind CdCl2 and decreased its cytotoxicity and genotoxicity; however, Tunisian clay was more efficient in binding with the CdCl2 than Egyptian clay.

Reverse Engineering Using Close Range Photogrammetry for Additive Manufactured Reproduction of Egyptian Artifacts and Other Objets d'art2

Photogrammetry has been in use for over 150 years. This research considers how digital image capture using a medium range Nikon digital single lens reflex (DSLR) camera, can be transformed into 3D virtual spatial images, and together with additive manufacturing (AM) technology, geometric representations of the original artifact can be fabricated. The research has focused on the use of photogrammetry as opposed to laser scanning (LS), investigating the shift from LS use to a single DSLR camera exclusively. The basic photogrammetry equipment required is discussed, with the main objective being simplicity of execution for eventual realization of physical products. As the processing power of computers has increased and become widely available, at affordable prices, software programs have improved, so it is now possible to digitally combine multiview photographs, taken from 360 deg, into 3D virtual representational images. This has now led to the possibility of 3D images being created without LS intervention. Two methods of digital data capture are employed and discussed, in acquiring up to 150 digital data images, taken from different angles using a single DSLR camera together with the specific operating conditions in which to photograph the objects. Two case studies are documented, the first a modern clay sculpture, while the second, involves two 3000 year old Egyptian clay artifacts. All and the objects were recreated using AM technology. It has been shown that with the use of a standard DSLR camera and computer software, 2D images can be converted into 3D virtual video replicas as well as solid, geometric representation of the originals.

Synthesis of Faujasite from Egyptian Clays: Characterizations and Removal of Heavy Metals

Three clay samples with different mineral compositions (kaolinite, smectite-kaoline, and smectite-rich) were used for zeolite synthesis using the method of hydrothermal reactions after fusion with NaOH. The conditions of hydrothermal crystallization (zeolitization) were found to be at temperature of 100°C, and time span between 72 h and 96 h for kaoline and smectite-rich samples, while 48 h for the smectite-kaolinite sample. The results indicate that zeolites began to crystallize from clay samples after 48 h, and crystallization increased with increasing time. The synthetic materials have been characterized by X-ray diffraction (XRD), scanning electron microscope (SEM), fourier transform infrared spectroscopy (FT-IR) and thermogravimetric (DTA/TGA) analysis. The results indicate that low silica NaX-faujasite type with well-developed octahedral and cubic crystals was synthesized from the three samples. No big difference in the characterization between the three synthetic materials was detected, but smectite-kaolinite sample as raw material was relatively better in crystallization of synthetic zeolite. Applications of the synthetic materials in the removal of heavy metals proved that the synthetic faujasite has strong effect for removing of Cr3+, Co2+, Ni2+ and Mn2+ from aqueous solution.

Zinc Oxide Doped Red Sea Egyptian Clay as a Varistor

Clay consists of about 50% SiO2 + 25% Al2O3 plus some other oxides with low abundance ratio like CaO, TiO2, Fe2O3, MgO and Mn2O3. Burning the clay at 700°C removes out the organic compounds and the mentioned oxides only remain. Our aim is to dope ZnO by the remaining oxides for varistors fabrication. Six types of clay were collected from Egyptian Red Sea Coast mines, after burning for 2 hrs the remaining oxides were mixed and ball milled with ZnO for 10 hrs according to the formula (100-Xn) ZnO +Xn, where n is the clay type and X is the ratio of the clay in grams, X takes the values 0.525 in 15 steps. Samples were pressed and sintered at three different temperatures (Tsin) 1200°C, 1300°C and 1400°C for 1 hr, and then studied via XRD, SEM, EDAX, J-E and C-V measurements. The obtained results were discussed in terms of the microstructure of the samples and the formation of Schottky barriers. Barrier height Ф, width W, interface state density Ns and donor state density Nd were calculated for the samples with highest nonlinearity α. It was found that the breakdown electric field Eo is related exponentially with the ratio of Zinc silicate phase whereas α scales with ratio of ZnO phase and the later increases linearly with Tsin. The electrical characteristics of the most promising sample were compared with those of ZnO samples doped pure SiO2 and Al2O3 obtained at the same preparation condition. This sample is comparable with the Japanese commercial varistor 5N220k Dc JVR.

Assessment and Utilization of Some Egyptian Clay Deposits for Producing Lightweight Concrete

The clay materials were collected from Fayoum area (F- type) and Alamine area (A- type and S- type). Swelling and PH measurnments for the selected raw clay materials were measured. Chemical and mineral composition was investigated using XRF and XRD, respectively. Chemical analysis confirms that F type has higher alumina than the other two types of clay A and S. Kaolinite is an essential mineral in F type while it occurs in minor amount in A and S types. Montmorillonite detected classified into calcium montmorillonite and sodium montmorillonite. Calcium montmorillonite is observed in F type while sodium montmorillonite is detected in both samples of S and A types. PH value results refer to the F type is slightly below 7 while the S and A types are above 8. Swelling measurements showed also different values in the three types of clay materials reaching a value of 300% in S- types 100% in soil A and 50% in F- type. The data of swelling and PH confirm the distribution of montmorillonite in the three types of clay materials. The bloataility of the fired granules in term of density show that the lowest density for A and S types (0.84 and 0.65 g/cm3 at 1150o C respectively.) compared with the F type (1.75g/cm3) at 1200o C. XRD patterns of the fired clay samples confirm that A and S mainly composed of quartz and hematite as well as some albite in restricted to A type. F sample record mullite in addition to the cristobalite and quartz. Lightweight concretes blocks of low density and relatively good strength are tested for producing and utilized in modern building trend for dead–load construction and wall construction were prepared from clay materials under investigation by firing the A and S types up to 1150oC using a rate of heating 20oC/min

The Inside Out of Childhood Archaeology

ABSTRACTTwo identical ceramic rattles dated to the Early Islamic period (ninth–eleventh centuries CE), retrieved from excavations at Mishmar David (Israel), were studied using petrographic analysis and x-ray radiography. The petrography shows that the rattles were made of a typical Egyptian Nile Valley clay, while the x-ray radiography provides important data regarding their interior, including the sounding elements they contain. Given the rarity of contemporaneous ceramic rattles and the foreign origin of the specimens, the present study contributes to the broader discipline of childhood archaeology in the Early Islamic Near East, providing additional evidence of the Egyptian presence in Early Islamic Palestine, and contributes to a better understanding of the technology used in the manufacture of these mundane objects.