Papers by Keyword: Clay

Abstract: The kinetics and mechanism of transesterification of Shea butter to produce fatty acid methyl ester (FAME) were investigated using a catalyst developed from clay impregnated with barium chloride (CD-BaCl₂). The catalyst was prepared by mixing 10% BaCl₂ chloride with clay, drying it, and calcining it at 600°C for four hours. The synthesized catalysts were characterized using X-ray Diffraction (XRD), Scanning Electron Micrograph (SEM), Brunauer-Emmett-Teller (BET), X-ray Fluorescence (XRF) and Fourier Transform Infrared Spectroscopy (FT-IR) to determine their suitability. The effects of methanol/mol ratio, catalyst concentration, temperature, agitation speed and time on FAME production were evaluated using the synthesized catalyst. Two elementary reaction mechanisms, Eley-Rideal (ER) and Langmuir-Hinshelwood-Hougen-Watson (LHHW) were used to analyze the kinetics. CD-BaCl₂ effectively converted Shea butter into FAME, and variations in the process parameters had a significant impact. A 4wt% catalyst dosage, a 10:1 methanol/oil molar ratio, a 2-hour reaction time, a speed of 300rpm, and a temperature of 60°C resulted in approximately 70% FAME. The kinetic results showed that LHHW provided the best representation of the experimental data with the CD-BaCl₂ catalyst. The rate-determining step (RDS) was the surface reaction linking the adsorbed triglyceride and adsorbed alcohol. The rate increased with temperature, indicating an endothermic reaction. The activation energy and frequency factor for the reaction were 2.49 kJ/mol and 8.61 h^-1, respectively, occurring at a temperature below the boiling point of methanol. The model's capability was evaluated by validating the experimental data, showing a good relationship. Keywords: FAME, shea butter, LHHW, ER, clay

Abstract: This study aims to improve the mechanical and thermal properties of clay-based ecological bricks. It explores the incorporation of wood ash or crushed pottery waste in environmentally-friendly bricks. Laboratory tests have determined the optimum dosages: 20% wood ash combined with clay and 5% pottery waste. These mixtures increase the thermal resistance of bricks, thus reducing their heating and cooling demand, in line with Morocco's Thermal Building Regulations (RTCM2015). The study also aims to examine the thermophysical behavior of clay blocks stabilized with these additives.

Abstract: 3D printing of ceramics grabbed its attention recently because of its ease of shaping. The extrusion-based 3D printing technique is widely used for ceramics as it involves paste formulation. However, the slurry is often formulated and mixed initially by hand kneading and later by a high-speed mixer. This phenomenon leads to the evaporation of water quickly while combining or out of its insufficient time allowed for extrudable slurry or paste formulation. The slurry's printable time is also reduced due to this phenomenon. This study prepares a hybrid ceramic mixture comprising silica gel, and printable time is calculated. Triaxial porcelain is used as a model ceramic.

Abstract: Clay minerals possess substantial potential for developing innovative functional materials, particularly in the context of environmental protection. This study focuses on the adsorbent zeolite-clay and bentonite-clay, shaped into honeycomb monoliths to efficiently remove Fe²⁺ ions from water. The process involved physically activating powdered zeolite-clay and bentonite-clay through calcination at 600°C. The activated materials were then mixed with distilled water and molded into monolithic shapes through extrusion with stainless steel molds, resulting in cylindrical structures measuring 1.8 cm in diameter and 2 cm in height, featuring 40 perforations. Mechanical characterization aimed to evaluate structural strength and assess pressure drop during operation, revealing superior mechanical strength in bentonite-clay compared to zeolite-clay. The monolithic form exhibited lower pressure drop during operation compared to pellet adsorbents. In terms of adsorption performance, a batch reactor assessed efficiency, isotherm, and kinetics with 2 and 4 ppm Fe2+ ion solutions over a 240-minute period. The zeolite-clay monolith demonstrated the highest capacity, achieving a removal efficiency of up to 65%. Maximal adsorption capacities for bentonite-clay and zeolite-clay were 0.209 and 0.289 mg/g, respectively, with corresponding Langmuir adsorption equilibrium constants (KL) of 0.187 and 0.181 L/g by the Langmuir isotherm model. Kinetic analysis favored the pseudo-first-order non-linear model, indicating rates for zeolite-clay and bentonite-clay adsorbents at 2 and 4 ppm Fe²⁺ ion concentrations of 0.0043, 0.0030, 0.0039, and 0.0038 min^-1. This study signifies a significant advancement in solid adsorbents, optimizing the adsorption process for broader applications.

Abstract: Water pollution poses a significant challenge to water consumption, particularly in relation to drinking purposes. Various factors such as industrial discharge, improper waste management, waste build-up, and natural activities contribute to the contamination of water bodies. Adequate water treatment plays a crucial role in the preservation of water quality and compliance with environmental regulations. The treatment process typically involves the application of physical, chemical, and biological techniques, with a common reliance on chemical substances and intricate systems. Recent studies have increasingly explored the utilization of cost-efficient natural materials for water treatment, highlighting benefits like affordability, user-friendliness, health advantages, and widespread availability. This particular investigation aimed to assess the suitability of selected natural substances for the treatment of wastewater, focusing primarily on methods like adsorption, absorption, and filtration. A number of earth materials, notably three distinct types of clays prevalent in Sri Lanka, were singled out for examination. The findings unveiled that these clays predominantly consist of over 75% iron in their mineral composition, with certain samples displaying finer particles to enhance porosity and permeability. These raw materials exhibit potential for the fabrication of wastewater treatment systems intended for the elimination of suspended particles, dissolved solids, heavy metals, pathogens, oils, and toxic compounds. Their distinct chemical properties render them appropriate for catalytic reactions and advanced chemical processes

Abstract: In this paper, the effect of two additives on the plasticity properties and drying sensitivity of a Hungarian clay were investigated. Two different sodium tripolyphosphate-based commercially available plasticizers (Fabutit 734, Budit 8H) were applied for experiments. The amount of the additives in the clay mass was changed between 0 and 0.5wt% relative to the weight of the dry clay and the plasticity was measured with two different methods. In addition to the plasticity of the clay mixes, the effect of the additives on the drying sensitivity was also analyzed with the Macey method. Results showed that the moisture content required to shape the clay body can be reduced by 1-1.5% with the mixing 0.1 and 0.2 wt% of Budit 8H additive.

Abstract: Plastic is an important necessity with the characteristics of being light, strong, relatively cheap, and durable. However, plastic cannot decompose in a short time so that it becomes a pollutant. The using of Poly lactic acid (PLA) is an alternative to synthetic plastics substitute such as Low-Density Polyethylene (LDPE) because it is degradable. However, PLA is brittle, so it requires a plasticizer in the form of additives, namely Polyethylene glycol (PEG) 200 and fillers in the form of clay and CaCO₃ to improve the mechanical properties of PLA which is brittle and has poor toughness. The purpose of this study was to determine the effect of adding additives to mechanical properties of PLA. The method used is solvent blending using chloroform as a solvent, stirring at 200 rpm for 6 hours at 30 . The research was conducted through testing the effect of the ratio of filler addition on the condition that the ratio of PLA/Additives was constant, i.e., 70%PLA/30% Additives. The resulting film is white and slightly transparent and has a smooth surface. The effect of adding additives in the form of plasticizers and fillers was tested through Dynamic Mechanical Analysis (DMA) analysis to determine the value of tensile strength, Young's modulus, and elongation break. The best result was obtained at a ratio of 25%CaCO₃/Clay, which was increasing elongation at break 7.62%. It also indicated with best decreased percentage value of Young’s modulus, and highest crystallinity index of 39.86%. The worst value is obtained in variant of 50%CaCO₃/Clay that indicated with lowest tensile strength and decreased of % elongation at break. From this study, the best variant was recommended as a laminating plastic, that does not require high tensile strength for application.

Abstract: The continuous increase in vehicle uptake escalates the number of rubber tyre waste to avoid landfilling and stockpiling. The present research focused on the sustainable use of crumb rubber in clay roof tiles. Tile samples were fabricated by heating the compacted mixtures at 50°C for 72 h, followed by increasing the temperature to 200°C for 24 h. Clay, crumb rubber, NaOH, and Na₂SiO₃ with a 10% alkaline activator were adopted. The weight of the crumb rubber was 0.5%, 1%, 1.5%, 2%, and 2.5%. X-ray diffraction (XRD) and scanning electron microscopy (SEM) analyses to study the phases and microstructures of the samples. The present study found that the optimum crumb rubber concentration was 0.5%, and 1% satisfied the standard requirement for the roof tiles.

Abstract: Sanitary ware, including toilets, washbasins, and bathtub, plays a crucial role in maintaining hygiene and sanitation in various settings. The drying process is a critical stage in the manufacturing of ceramic sanitary ware, as it influences product quality, production efficiency, and energy consumption. Then, the purpose of this work is to investigate the drying of sanitary ware at low temperature by experiments and empirical mathematical models. The idea is to accurately predict moisture loss of the ceramic parts under different operational conditions. Results of the drying kinetics have shown that higher temperatures and lower air relative humidity accelerate the drying process. Also, no cracks or fissures were observed as a result of drying sanitary ware at low temperatures and the two-term model provides the best fit for the dimensionless average moisture content as a function of the time. These findings contribute to a better understanding of the drying process and support the optimization of sanitary ware manufacturing.

Abstract: The scarcity of drinking water is currently a critical issue in many parts of the world. Providing clean/urgent longer limited to natural sources. Wastewater treatment has become an urgent necessity in many countries, particularly in the Middle East and North African regions characterized by a desert climate. Hence, the development of effective methods for wastewater treatment is vital to overcome this water shortage. The present study attempts to explore the use of local clay from the United Arab Emirates (UAE) to prepare porous ceramic membranes (flat disk shape) for the purpose of removing toxic heavy metals from contaminated water. Two types of ceramic membranes were prepared by powder metallurgy method; the first type was prepared by uniaxial compression of the clay powder with particle size ≤ 250 μm, followed by sintering. The second type of membrane was composed of an activated carbon/clay powder mixture at different ratios (0.5%, 3% w/w). The activated carbon was used as an agent to form porosity in the plain clay membrane. The activated carbon was found to affect the final characteristics of the flat disk membranes sintered at 1000°C. 3% w/w activated carbon/clay powder was found to induce 19% porosity in the flat disc. The flat disc membranes were also characterized by X-ray diffraction, and scanning electron microscopy, X-ray fluorescence. The plain clay and 3% w/w activated carbon membranes were tested for their efficiency for water permeation. The results proved that the UAE clay could be considered as a promising material for the fabrication of ceramic membranes for prospective use in the removal of water contaminated with heavy metals.