Browsing by Author "Jayaweera, JMN"

Now showing 1 - 5 of 5

item: Conference-Extended-Abstract
Effect of Reflux temperature on synthesis of hdroxyapatite by wet chemical precipitation technique
(2011) Adikary, SU; Jayaweera, JMN; Sewvandi, GA
In this study, hydroxyapatite HA, [(Ca>o(P04)6(OHi:,j] was synthesized using wet chemical precipitation technique at different reflux temperatures. Calcium hydroxide [Ca(OH)J powder and Phosphoric acid [H3PO4] solution were used as starting materials. Variation in PH value of Ca(OHsuspension during the addition of H}P04 solution was analyzed. The effect of reflux temperature for the synthesis HA was investigated. Characteristics of synthesized powder were analyzed by Fourier transformed infrared (FTIR) spectroscopy and X-ray dijfraction (XRD). The powder characteristic has demonstrated that, the reflux temperature played an important role in the synthesis of pure and single phase HA powder.
item: Conference-Full-text
Effects of kaolin with high silica content on properties of ceramic tiles
(IEEE, 2022-07) Jayaweera, JMN; Narayana, M; Adikary, SU; Rathnayake, M; Adhikariwatte, V; Hemachandra, K
In general, Quartz, Feldspar, Ball Clay, and Dolomite are the main raw materials used in the tile industry. The availability of quality Ball Clay for the tile manufacturing industry has decreased over the years in Sri Lanka and the tile industry intends to substitute ball clay with another suitable clay. In this study, the New Kaolin source was investigated for the tile industry as the main clay mineral with Feldspar, Dolomite, and Bentonite Clay. Initially, new Kaolin clay was characterized using X-ray diffraction, wet chemical analysis, and differential thermal analysis. It consists of 56.78% of Silica. The body mix of the tiles was prepared and the Particle size distribution of the body mix was determined. The shape of the tiles was obtained using a powder pressing method. Samples were dried in an oven and fired in a muffle furnace at 1100°C, 1150°C, 1180°C, and 1200°C. Relationships between the physical properties of the fired tiles have been established. The improved physical properties of tiles at the firing temperature of 1200 0C complied with ISO 13006 standard. Based on this study, M2 Kaolin can be strongly recommended as a highly appropriate clay material for the ceramic tiles manufacturing industry in Sri Lanka.
item: Conference-Full-text
Numerical modeling of drying behavior of ceramic tiles with high silica content of kaolin
(IEEE, 2023-12-09) Jayaweera, JMN; Narayana, M; Adikary, SU; Abeysooriya, R; Adikariwattage, V; Hemachandra, K
The drying process of the green ceramic body is concurrent and coupled with heat and mass transfer phenomena. Dimensional variations and mechanical stresses occur within the body during the drying process. In this research, the drying behavior of ceramic tile was investigated, and a ceramic tile body mix was developed using M2 kaolin clay as the main clay mineral. Initially, the composition and structure of the M2 kaolin clay were analyzed using X-ray diffraction and wet chemical analysis, and it consists of 56.78 % silica. The body mix of the green ceramic tile was prepared, and the particle size distribution was analyzed. The powder pressing method was used to obtain the shape of the tiles. Samples were dried in an oven at 80 oC and the moisture variation of the green ceramic tile was determined with time. A mathematical relationship was formulated to determine the drying behavior of green ceramic tiles. An unsteady three-dimensional model was formulated and simulated in the computational fluid dynamics (CFD) framework. Results developed by the simulated model were compared with data obtained by experiments conducted using green ceramic tiles. The model results were validated and complied with the experiment results, and the R2 value was 0.9
item: Conference-Full-text
Numerical modeling of drying behavior of Sri Lankan kaolin
(IEEE, 2021-07) Jayaweera, JMN; Narayana, M; Adikary, SU; Adhikariwatte, W; Rathnayake, M; Hemachandra, K
Drying process of green ceramic bodies are complicated due to simultaneous and coupled heat and mass transfers. Dimensional variations and mechanical stresses occur within the ceramic body during drying may create defects in the final product if drying conditions are not carefully controlled. In this study, the drying behavior of Sri Lankan Kaolin was investigated. Initially, Kaolin was characterized using wet chemical analysis and X-ray diffraction to investigate structure and composition. Two batches of Kaolin with different particle size distributions were prepared using wet ball mill grinding with average particles size (D50) of 4.07 μm and 3.57 μm respectively. Green ceramic samples were obtained using extrusion process. Samples were dried in oven at 60°C and moisture variation of the green product was measured with time. Critical moisture content of the Sri Lankan Kaolin was 1.50%. Mathematical relationship was formulated to determine drying behavior of Sri Lankan Kaolin. An unsteady three-dimensional (3D) model was developed and simulated in Computational Fluid Dynamics (CFD) framework. Simulation results developed by the model were compared with data obtained by experiments conducted using Sri Lankan Kaolin. The model results were validated and comply with experiments results and R 2 value was 0.9.
item: Conference-Abstract
Synthesis and characterization of hydroxyapatite to be used as a bio-material
Adikary, SU; Jayaweera, JMN; Sewvand, GA
Ceramics are a versatile group of materials that are abundant in type. Some ceramics that have been tested in vivo do not cause increased activity in the immune system when dissolved in body fluid or in contact with tissues. Such ceramics, mainly oxides, are termed bio-ceramics. Bio-ceramics have the advantage of being compatible with the human body environment. As reported by Erdem and Ahin (2006), these bio-ceramics include calcium phosphates, Bio-glasss, A-W glass-ceramic and other bioactive glasses and glass-ceramics with hydroxyapatite being the prominent family member, Bioceramics are generally used to repair or replace skeletal hard tissues. Narupom M (2008) states that Hydroxyapatite [HA] is a bioactive, biocompatible calcium phosphate based ceramic material that possesses a structural and chemical composition similar to the mineral component of human bone tissue. There are several methods of preparing HA crystals reported in the literature, including wet chemical precipitation by Narupom M, (2008), solid-state reaction and hydrothermal methods by Chun-Wei Chenn et al (2004) etc. According to Guzm'an V'azquez, et al (2005), wet-chemical precipitation route is the most prominent route owing to its ease in experiment operations, low working temperature, yield of hydroxyapatite and low cost equipment requirement C. Therefore in the present study, wet chemical precipitation technique was used with analytical grade Ca(OH)2 powder and H3PO4 acid as starting materials. A.Binnazhazar yoruc and Yeliz koca, (2009) and some other authors concluded that the shape, size and specific surface area of the HA particles obtained by this method are very sensitive to the dropping rate, reaction temperature, pH value, stirring speed, method of stirring, reflux temperature, ageing time, etc. The purpose of this study is to produce high quality and purified hydroxyapatite for artificial bone application.