Local Clay Research Articles

Comparative study of the chemical, structural and adsorptive properties of local thermally activated clay and an imported commercial clay for the depigmentation of crude palm oil

The present study investigated the performance of raw kaolinite clay (Ao), thermally activated local kaolinite clay and an imported commercial clay (AIC) for the depigmentation of crude palm oil. The local clay was thermally activated at 400 °C/1 h (A1), 600 °C/1 h (A2) and 600 °C/2 h (A3). Standard analytical methods such as X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), nuclear magnetic resonance (NMR), scanning electron microscopy (SEM) and Brunauer-Emmett-Teller (BET) surface analysis were used to characterize the different materials. Batch adsorption was used to carry out experiments on the decolorization of crude palm oil. During this process, the effect of parameters such as contact time, adsorbent dose, acidity and stirring speed were evaluated. The physicochemical characteristics revealed that the A3 clay has a larger variety of functional groups and active sites (Si/Al ˂ 1) and a higher specific surface area (28.62 m2/g) than the A1 and A2 clays. The active sites in A3 activated by calcination compensate for the functional group deficit compared with the commercial clay AIC as evidenced by the comparable depigmentation efficiency of crude palm oil. The characteristics of the oil decolorized with A3 and AIC clays revealed negligible impurities, water content and volatile matter, and indistinguishable coloration of 15.8 R30Y for an optimum depigmentation time of 30 min. The acid, iodine and peroxide values of the oils treated with A3 and AIC show that the oils are not deteriorated by the clays during the depigmentation process. Since the performance of the materials are indistinguishable, the tradeoff between importation costs and costs of thermal treatment indicates that the use of local kaolinite clay of Njinon, is plausible alternative for use in the palm oil refining process with higher potential of trickle-down economics effect to the local economy relative to adsorbent importation.

Cooking pottery as indicator of resilience and change in Early Medieval Cyprus. An archaeometric approach

The early medieval times in Cyprus are signified, conventionally, by the Arab invasions of the mid-seventh century (649/650CE). Past research viewed those events as the catalyst which led to a transformation from a prosperous province to a marginal territory balancing between two antagonising empires. Recently, studies have shifted their focus on reassessing this period’s scant -yet present- material culture. In pottery studies, despite the advances in typological and distribution aspects, few have explored technological issues of early medieval ceramic production through instrumental analysis. This study focuses on the compositional and technological characterisation of cooking vessels through ceramic petrography (TL-OM), found in relevant contexts in Cyprus, representing both wheel-thrown and handmade traditions. Sherds coming from five major early-medieval sites of the island (sites of Kophinou, Kalavasos-Kopetra, Akrotiri, Yeroskipou-Ayioi Pente and Dhiorios), outlined a picture of two parallel trends transversing across sites, i.e., an inter-regional shared sense of shape uniformity smoothening the local variances and a strong regionalism in terms of raw material procurement. Wheel-thrown cookware -found in every site and strongly represented by the Dhiorios workshop- showed the survival of Late Antique shapes well into the Early Middle Ages, in fabrics related mainly to the broader area of Dhiorios. In addition, handmade vessels of a "shared repertoire" showed a variety of local clays for their manufacture. When integrated into their archaeological context in Cyprus, the results support the idea of a ceramic koine persisting through the beginning of the Byzantine Early Middle Ages on an intra and inter-regional level.

Development and characterization of a clay-based composite reinforced with doum fibers

This paper investigates the effects of Doum fiber as a local materials, on the mechanical strength properties of cylindrical earth samples with a diameter of 3 cm and a height of 4.5 cm. Untreated and Alkali treated Doum fiber with a NaOH concentration of 1%, 4%, 6% are introduced in local clay with a ratio of 0.5%, 1% and 1.5% by weight of the earth samples. A tensile test of the Doum fiber and a compressive strength test of the elaborated specimens is conducted. The study findings outline an improvement in the mechanical properties of the earth samples and adherence between surface fiber and soil when the fiber is treated. And a dosage of 0.5% by weight of Alkali treated Doum fiber with a NaOH concentration of 1% is sufficient to achieve higher mechanical performances. Modifying the fiber surface through NaOH treatment enhances fiber adhesion to clay and improves the mechanical behavior of the biocomposite.

Characterization of Some Local Clay Minerals and Fabrication into Ceramic Floor-Tiles

Clay minerals deposits, which include, kaolin, ball-clay, fireclay and zircon, were investigated and used in fabrication of ceramic floor tiles. X-ray diffractometer (XRD-6100, Japan), was used to examine the various compositions and structures of the clay samples. 2000 grams of 0.005 mm grain size of each sample were homogeneously mixed into dough, compressed in metallic mould of 12 mm × 36 mm dimension, and allowed to dry for about 5 hours. Kiln draught oven, at 1200°C was set for glazing and firing of the moulded tiles, to ensure glossy appearance, smoothness and improved strength. XRD test showed higher content of alumina (Al<sub>2</sub>O<sub>3</sub>) and Silicon (iv) oxide (SiO<sub>2</sub>) in all the clay samples. The percentage composition of Critobalite, Diphosphorus trioxide (P<sub>2</sub>O<sub>3</sub>), Potassium Oxide (K<sub>2</sub>O) and Sodium Oxide (Na<sub>2</sub>O), were reasons for their excellent workability, improved mechanical and rheological properties of ceramics floor-tiles. Water absorption, chemical resistance, shrinkage properties of the different ceramic tiles were compare to some commercial products. This investigation had shown that locally available clay minerals could be fully integrated into ceramic industries to reduce cost of ceramic importation and create job opportunities for youths.

PREPARATION AND CHARACTERIZATION OF POLYMER INCLUSION MEMBRANES BASED ON BIODEGRADABLE CELLULOSE/ALGERIAN CLAY FOR HEAVY METALS REMOVAL FROM WASTEWATER

Separation membranes have gained attention as promising options for water and wastewater treatment due to their financial sustainability, and eco-friendliness. However, practical challenges have limited their application in water separation. To overcome these limitations, inorganic-organic hybrid membranes have been developed in this study. The present work deals with two attractive aspects: (i) economical, through the valorization of a local clay (Algerian kaolin), and (ii) environmental, which is based on the membrane selectivity for metal ions. The principal objective of this work is the development of enhanced nanocomposite membranes. It is achieved with low costs, based on cellulose triacetate (CTA) as a polymeric matrix modified by the addition of a lamellar filler, i.e. yellow clay obtained from Jijel, located in the east of Algeria, and plasticized by dioctyl phthalate (DOP). A further objective of this paper was the treatment of wastewater polluted by lead (Pb2+) and cadmium (Cd2+). The prepared membranes were characterized by various characterization techniques, including scanning electron microscopy (SEM), Fourier-transform infrared (FTIR) spectroscopy and thermogravimetric analysis (TGA). All synthetized membranes had an amorphous structure, with homogeneous pore morphology and distribution. Moreover, the presence of nanocomposite clay showed effective integration into the membrane matrix and led to a significant improvement in thermal resistance. These membranes were applied to treat a synthetic aqueous solution contaminated with heavy metals, namely Pb2+ and Cd2+. The results revealed a rejection rate higher than 50%, suggesting the potential effectiveness of a stable and environmentally sustainable polymer inclusion membrane system for water purification.

Marble-Looking Fired Clay Tiles Produced by Utilizing Local Clay and Glass Cullet

This research is aim at developing marble-looking fired clay tile by utilizing waste glass cullet (CGC) mixed up with local plastic clay, sediment soil, and laterite clay. Boric oxide is also used as sintering aid. The experimental formulation is divided into 3 groups (A, B, and C) with 27 formulas. Test samples are moulded at 100 bar by Uni-axial pressing in dimension 50 x 100 x 7 mm and fried at temperature 850 °C. The initial results show that all formulas can develop marble texture and achieve Thai Industrial Standard TIS 2508-2555. Reducing firing temperature to 800 °C is the further investigation. However, formulas consisting 90% glass cullet are not selected, due to difficulty of molding workpieces. The final results of firing 800o C show that formula A6 containing 15% Plastic clay, 85% glass cullet, 2% boric oxide has the highest bending strength and lowest water absorption (<1%). Its properties are similar to formula C6 containing 15% laterite soil 85% glass cullet, 2% boric oxide. They can pass Thai Industrial Standard TIS 2508-2555 Floor Tiles BIb. Analyzing microstructure the fired specimens of these formulas by Scanning Electron Microscope has found glassy phases and dense matrix structures. Furthermore, Nepheline, Quartz, Cristobalite, Wollastonite, Devitrite, and Albite are identified by X-Ray Diffractometer. It can be summarized that marble texture surface fired clay tile can be developed by utilizing waste glass and low cost local materials.

Advancing sustainable construction: Terracotta component development through extrusion-based 3d printing with local clay

This study examines the use of 3D printing technology in construction, specifically the use of local clay as the primary material for developing Terracotta components. The results demonstrate the feasibility and high print quality achievable with clay, establishing it as a viable material for 3D printing in construction. The analysis of physical properties, such as shrinkage, density, and water absorption, provides valuable insights. Thermal conductivity, also examined, contributes to a comprehensive understanding of material performance. The article identifies the optimal extrusion parameters for terracotta components. The evaluations show that the water absorption rates are within standards, and the density variation ranges from 1420 to 1466 kg/m³. Additionally, there is a direct correlation between thermal conductivity and density. The compressive strengths are diverse, ranging from 18 MPa to 33 MPa. While modulus of elasticity provides essential quantitative data for understanding the mechanical behavior of printed samples when subjected to various stresses. The internal structure significantly influences compression resistance in 3D printed bricks, emphasizing its importance in design. This research highlights the potential of 3D printing, specifically with clay, in sustainable construction. It encourages further exploration of its practical applications in the industry.

Development of lightweight structural concrete with artificial aggregate manufactured from local clay and solid waste materials

The partial replacement of conventional natural coarse aggregate (NCA) with artificial light weight aggregate (LWA) manufactured from local clay and solid waste to develop a lightweight aggregate concrete (LWAC) for the structural use was studied in this paper. Red clay and Savar clay were used individually with solid wastes like rice husk ash (RHA) and waste glass to produce LWA. The suitability of raw materials and LWA was evaluated by investigating various properties. The mechanical, thermal and durability properties of manufactured LWAC were explored. The results of physical, chemical, thermal and geotechnical properties revealed that Red clay is better than Savar clay for the preparation of LWA. All the physical and mechanical properties of LWA prepared from Red clay are suitable for the preparation of LWAC compared to Savar clay. The test results demonstrated that the concrete manufactured by replacing 30 % of NCA with LWA produced a concrete of lightweight properties. The compressive strength of LWAC for 7 and 28 days was observed as 28 and 48 MPa, respectively. The results of modulus of elasticity, splitting tensile strength, flexural deformation, and creep test of LWAC revealed that these mechanical properties meet the requirements for the structural concrete. The RCP test proves that chlorine permeability of LWAC is comparable with NCA. It was observed that the superior performance of LWAC can be achieved only when the optimized mix designed is followed strictly. The suitability of the replacement of natural aggregate by LWA may be helpful for Bangladesh due to the scarcity of natural coarse aggregate and reusability of solid waste materials.

Deciphering the Mortar Composition of Ancient Chinese Pagodas: A Comparative Analysis from the Tang to Ming Dynasties in Shaanxi Province

The mortar materials from the internal and external walls of ancient Chinese pagodas in Shaanxi (Luoshan Temple Pagoda (847–858 AD), Daxiang Pagoda (960–1279 AD), and Qianjin Pagoda (1609 AD)) were investigated. Qualitative and semi-quantitative techniques including scanning electronic microscopy (SEM), energy-dispersive spectroscopy (EDS), X-ray diffraction (XRD), attenuated total reflection Fourier transform infrared spectroscopy (ATR-FTIR) and thermogravimetric analysis with differential scanning calorimetry (TGA-DSC) were employed. The physical and chemical characteristics including microstructural morphology, chemical composition, element distribution, and organic additives of the mortar samples were studied. SEM indicated that the mortar from the external wall exhibits a tightly bonded matrix, with the irregularly shaped particles, and the carbonation of the calcium carbonate in the mortars closely resembles that of aragonite crystals. The results of EDS, XRD, FTIR and TGA-DSC revealed that mortar from external wall of these ancient pagodas were air-hardened lime, and complete carbonization with no traces of calcium hydroxide, while mortars from internal wall primarily comprises local clay and lime. In addition, ATR-FTIR and iodine-starch discoloration tests confirmed that the presence of starch in the external wall of Daxiang Pagoda, whereas no organic additives were detected in the Qianjin and Luoshan Temple Pagoda.

Clay Properties in the Mukdadiya Formation for Drilling Fluid Production from Shorau and Shewsoor, N Kirkuk, Iraq

The present study involves assessing the potential of the clay layers in the Muqdadiya Formation (late Miocene–Pliocene) for use in oil well drilling fluids. It is achieved through conducting various tests on the samples under investigation and comparing the results with the standard specifications for drilling fluids set by the American Petroleum Institute (API). The study also compares the effectiveness of different additives in improving the local clays and the impact of adding XC-polymer on the current wicking values. It has been found that XC-Polymer possesses superior properties compared to other polymers when used in the same concentrations. This substance is extremely important due to its direct correlation with the operation of drilling fluid. The test was used to determine that the two research models (Shorau and Shewasoor) at their usual concentrations did not produce the necessary characteristics of the drilling fluid in accordance with API requirements. Appropriate specifications for the drilling fluid were obtained by conducting a series of laboratory tests, increasing the model's concentration to 25 grams, and adding high-viscosity CMC and XC-Polymer to the sample in order to assess the current properties of the two study models in fresh media. The Shurao (M1) and Shewsoor (M2) models did not show current properties suitable for drilling fluid in salty media. After adding XC-Polymer to 25 grams of the models activated with 4 grams of Na2CO3, the two study models showed a response to the activation process and obtained results for current properties suitable for drilling operations in salty media. It turned out that the Shewsoor model had more appropriate specifications than the Shorau model.

Tuning the Hydrothermal Synthesis of FAU-type and ANA-type Zeolites Derived from the Philippine Bentonite

The synthesis of zeolites from local resources has been an attractive route to address the demand for more economical means in the production of zeolites for commercial applications. In particular, Philippine bentonite – a local clay material –has been used as a raw ingredient to synthesize zeolites, faujasite-type (FAU), and analcime-type (ANA) via hydrothermal synthesis. The silicon-aluminum ratio (SAR) and crystallization temperature were varied to investigate the conditions in the synthesis of pure FAU and ANA-type zeolites. X-ray diffraction allowed the identification of zeolite phases upon comparison to reference patterns from the International Zeolite Association database. The sample with the highest degree of crystallinity of 98% (ANA-type) was prepared at a temperature of 150 °C and an initial SAR of 1.18. This sample also exhibited the largest particle size of 29.1 μm in diameter. Scanning electron micrographs showed octahedral, spherical, and cross morphologies of the products, with average particle size ranging from 1.24 (± 0.13) to 29.1 (± 1.66) μm. The transformation of Philippine bentonite to different types of zeolites demonstrates the viability of local clays as raw resource material for hydrothermal synthesis of a wide range of zeolite frameworks.

Adsorption isotherm and kinetic modeling of malachite green (MG) dye on cost-effective mesoporous material Al-MCM-41 synthesized from local clay

Adsorption isotherm and kinetic modeling of malachite green (MG) dye on cost-effective mesoporous material Al-MCM-41 synthesized from local clay

Synthesis, characterisation and application of organic and inorganic bentonite for the removal of gentian violet

ABSTRACT The intensive use of dyes in industry has caused serious pollution problems, due to industrial wastewater discharges. It is well known that dyes have harmful effects on humans, animals, and other living beings. Therefore, the treatment of industrial wastewater before its release into the environment requires great attention. This work is devoted to the study of the effect of organic modifications by DMSO and/or CTAB and an inorganic modification by spinel oxide ZnCr2O4 on the structural and textural properties of local clay (M’Zila bentonite). The materials resulting from these modifications are used as adsorbents for a cationic dye such as gentian violet. These materials were synthesised and characterised by XRD, FTIR, BET and SEM. These analyzes confirmed the considerable changes in the structure of the clays modified by DMSO and/or CTAB- ZnCr2O4, the formation of pillared bentonites and the increase in the basal spacing’s of the modified clays by 15.05 Å for the bentonite of M’Zila at 23.80 Å for bentonite-CTAB-ZnCr2O4 (BCZnCr), at 27.37 Å for bentonite-DMSO-ZnCr2O4 (BDZnCr) and at 25.89 Å for bentonite-DMSO-CTAB-ZnCr2O4 (BDCZnCr).These modifications produced a rougher and more porous surface, resulting in a significant increase in the specific surface area from 60.13 m2 g−1 for sodium bentonite to 104.63 m2 g−1 for BCZnCr and 104.59 m2 g−1 for BDCZnCr. The adsorption of gentian violet was carried out under the following conditions: solid liquid ratio: 1 g/L, pH = 10 and contact time at equilibrium 1 h. The adsorption kinetics perfectly follows the pseudo second order model as well as that of intraparticle diffusion for all materials. The isotherms are of type S; they are well described by the Langmuir-Freundlich model. The thermodynamic parameters indicate that the physisorption of gentian violet by the different materials is spontaneous, exothermic, and disordered.

An Archaeometric Study of the Iron Age Ceramics from Quinta do Almaraz Archaeologic Site (8th to 5th Centuries BC)—Colour and Mineralogical Characterization

The ceramic pastes of ca. 31 samples recovered from the Almaraz archaeological site, located in the south bench of Tagus River, were studied in detail using XRF, micro-Raman and GSDR spectroscopies, as well as the XRD technique. The ceramic sherds could be grouped into six categories, red slip tableware, decorated tableware, yellow slip tableware, grey tableware, common tableware, and handmade pottery. Our studies of the mineralogic composition of the sherds’ body indicate all ceramics were produced locally, using siliceous clays in most cases and calcareous clays in a few ones. Micro-Raman and ground state diffuse reflectance absorption spectroscopy provided useful information regarding the materials used to produce the coloured ceramics: hematite and brookite for the red slip and decorated ceramics, jacobsite or carbon black for the black decoration or grey ceramics. For the yellow slip tableware, a simple engobe rich in yellow clay was used. XRF spectroscopic studies provided the elemental composition of all samples, and biplots of the potassium (K) versus calcium (Ca) contents, normalized to the silicon content of each ceramic paste, clearly show Pliocene and Miocene local clays sources were used to produce most ceramics. Only one sherd can be considered a Lisbon production.

Preliminary result of archaeological and petrographic classification of Neolithic pottery from Bahçelievler settlement in Northwestern Anatolia

In prehistoric archaeology, pottery is a significant fragment in defining and making sense of the culture. The pottery forms and the differences in the variety of decorations are used together with other archaeological elements in the stratification of the settlement at the local scale. Bahçelievler settlement is located in the southeast of the Marmara Sea and in a mountainous area, unlike many other settlements with similar cultural characteristics. Bahçelievler Neolithic settlement was inhabited for the first time between 7192 and 7052 BCE and continued to be used until 6063–5971 BCE. Therefore, the settlement in question has a crucial role in the beginning and development of the Pottery Neolithic Period, especially in Northwestern Anatolia. Both the differences in form variation and the change in decoration preferences, as well as the changes in undefined stone, limestone, quartz, volcanic rock, basalt, etc. additives, provide meaningful results in the settlement stratigraphy. As a result of petrographic research, Bahçelievler Neolithic potteries are divided into four main groups and are very compatible with the archaeological classification. Clay and clay paste used in pottery are almost entirely consistent with local clays. It has been understood that the tempered material, which is strictly compatible with the geology of the immediate environment, is preferred for pottery. Although different forms and ware groups were selected chronologically to evaluate all the data together, it can be quickly asserted that the samples were of local production.

Ethnoarchaeological examination of workspaces for rural producers of market-oriented wares

Communities of traditional female potters produced thousands of utilitarian market-oriented wares from local clays on the islands of Cyprus and Luzon in the 1980s. They worked inside and outside their homes, together with members of their nuclear family, or in a communal workspace. Although the physical evidence of production tends to be sparse, the two ethnoarchaeological studies of craft specialists discussed here provide clues to identify ancient potters who worked in their household courtyards. In Cyprus, a partial move to a dedicated village workspace, away from home courtyards, initiated the use of a communal kiln and a shift from reliance on help from spouses and children. At the same time, continuity prevailed for independent potters who continued to work at home. The household production of market-oriented pottery, by male and female craftspeople in Cyprus and the Philippines, supported their family and village while meeting the needs of customers in villages and towns.

Study Of the Optimum Conditions for Removing Phosphate from House Water in City of Mosul Using Some Local Clays

Study Of the Optimum Conditions for Removing Phosphate from House Water in City of Mosul Using Some Local Clays

Comparative analysis of energy performance between clay-based and conventional building materials: A case study in Moroccan semi-arid climate

The environmental challenges arising from using traditional construction materials, such as cement, along with their rapid depletion, underscore the necessity of employing environmentally friendly building materials derived from natural resources. In this context, this study presents a comparative analysis of the energy performance of conventional building materials and clay-based materials. Focusing specifically on the Beni Mellal region, adobe bricks reinforced with straw, at weight percentages of 0%, 2%, and 4%, were manufactured. First, the physicochemical properties of the investigated clay were characterized. Subsequently, the thermophysical properties of the fabricated bricks were determined. Annual simulations were conducted using the TRNSYS software, considering a typical meteorological year (TMY) for Beni Mellal City, located in the semi-arid climatic zone. The energy performance of various passive energy efficiency measures was evaluated and discussed, facilitating a thermal analysis to assess the energy needs for heating and cooling inherent to each building material. The results demonstrate that clay bricks, particularly those reinforced with 4% wheat straw, outperform conventional materials in terms of energy efficiency, highlighting their potential for sustainable construction. This study emphasizes the significance of local clay resources and natural reinforcements in enhancing energy efficiency and provides insights into their application in eco-friendly construction practices, thereby contributing to sustainable development goals

Possibility of obtaining Transparent Glaze from the Local clays of Qena Governorate

Possibility of obtaining Transparent Glaze from the Local clays of Qena Governorate

Physical Properties Investigations of Natural Rubber Composites Using Cetyltrimethylammonium Bromide (CTAB) as Modifier of Local Clay Filler

Improved absorption of rubber backbone on filler surfaces is necessary to enhance the physical properties of rubber vulcanizate. One of the ways to repair the surface of the filler is through modifying using surfactant. Hence, this study aims to compare the physical properties of natural rubber vulcanizates using clay filler and modified clay with cetyltrimethylammonium bromide (CTAB). The processes that were followed to achieve the objectives of this research were the design of rubber formulas, mastication and milling of rubber, and testing of the physical properties of rubber vulcanization. The clay characterization and its modification using FTIR and XRD were also carried out. Characterization using FTIR and XRD showed that there was indeed a clay modification with CTAB. Natural rubber compounds were also analyzed using SEM. The torque on the rheometer for modified clay with CTAB is 12.34 kg-cm higher than for original clay, which is 7.05 kg-cm. Elongation at break and tensile strength for vulcanizate using CTAB-modified clay filler is lower than that using original clay, with 300% modulus and hardness increase. Thus, clay modification using CTAB as a filler has a good effect on the curing characteristics and physical properties of natural rubber vulcanization compared to only using local clay as a filler.