The Effect of Commercial Rice Husk Ash Additives on the Porosity, Mechanical Properties, and Microstructure of Alumina Ceramics (original) (raw)
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Graphite waste from primary batteries, active yeast and commercial rice husk ash have been used as pore-forming agents to fabricate porous alumina ceramics using a fugitive materials technique. The pore-forming agent ratios were between 10 to 50 wt %. The effects of the pore-forming agent ratios on the mechanical properties, the porosity and the microstructure have been investigated in this study. The results showed that through increasing the pore-forming agent ratio for graphite waste, yeast and rice husk ash, the porosity increased from 37.3 to 61.1%, 30.2 to 63.8% and 42.9 to 49.0%, respectively. The hardness also decreased from 172.6 to 38.1 HV 1 and from 160.6 to 15.0 HV 1 for porous alumina ceramics using graphite waste and yeast as pore-forming agents, respectively. However, the hardness of the porous alumina ceramics with rice husk ash as a pore-forming agent increased at 30 wt % (150.9 HV 1) and 50 wt % (158.9 HV 1). The tensile strength for porous alumina ceramics using graphite waste and yeast as pore-forming agents decreased from 24.9 to 14.3 MPa and from 26.2 to 5.4 MPa. The compressive strength decreased from 112.3 to 34.3 MPa and from 19.5 to 1.8 MPa, respectively. However, for porous alumina ceramics using rice husk ash, the tensile strength increased at 30 wt % (24.1 MPa) and 50 wt % (21.9 MPa). The compressive strength also increased at 30 wt % (69.7 MPa) and at 50% (60.1 MPa).
International Journal of Engineering Research and Technology (IJERT), 2013
https://www.ijert.org/sintering-temperature-dependent-variation-of-compressive-strength-with-porosity-of-rice-husk-ash-ceramics https://www.ijert.org/research/sintering-temperature-dependent-variation-of-compressive-strength-with-porosity-of-rice-husk-ash-ceramics-IJERTV2IS90986.pdf This paper present compressive strength variation with porosity of ceramic made with Rice Husk Ash as the major raw material. The ash powder used in this work was initially produced at a controlled temperature of 650 0 C and the green strength ceramic disks formed by pressing method were then subsequently sintered at the temperature range of 1000 o C-1400 o C. The chemical composition of the rice husk ash was determined by XRF and the crystalline phases by XRD. The rice husk ceramics formed at this temperature range retained the same Si0 2 purity of 82.80% and major Impurities such as P 2 O 5 , K 2 O, and CaO. The result of X-ray diffraction shows the presence of two major forms of crystallographic phases; cristobalite and tridymite. Compressive strength increased with sintering temperature as porosity decreases. This result suggests a trade off on porosity for typical application like water filter design that requires combined high strength and porosity of the ceramic composite.
Phase Transitions, 2009
Silica ceramics were prepared using three types of raw materials derived from rice husk. Cleaned husk and acid-leached husk were burned at 700 C to get brown ash (BA) and white ash, respectively. The third type was silica gel (SG) derived from BA through the alkaline extraction of silica from ash followed by acid neutralization. Granulated powders were pressed and pellets were sintered at 700-1400 C range. Phase-formation behavior, densification characteristics, and mechanical strength of ceramics were investigated and correlated with microstructural features. Ceramics made of SG showed the highest density and mechanical strength among all. All the ceramics were initially amorphous and transformed into crystalline silica above a specific sintering temperature. Microstructure shows the formation of cracks in the ceramics when they contain cristobalite phases. Amorphous-to-crystalline phase transformation temperature in different types of silica source was dependent on the amount of impurity and residual hydroxyl group content.
Journal of the Ceramic Society of Japan, 2014
This study reports on the effect of soda-lime-silica (SLS) glass on the physical properties of the ceramic material obtained from white rice husk ash (WRHA). The crystallisation behaviour of samples was investigated by XRD analysis after different heat treatments. The bulk density and linear shrinkage (LS) of the samples were determined using Archimedes' method and direct geometric measurement, respectively. The residual pore contents of the specimens were determined using SEM micrographs. The results show that the bulk density and LS of the samples increased and the porosity decreased as the sintering temperature increased. The XRD analysis results show the formation of cristobalite to be a major phase and some tridymite phase was detected in the specimens.
Influence of Some Additives on the Properties of Porous Alumina Ceramic
2009
Production of porous alumina ceramics by the slurry casting method and pore formation by elimination of hydrogen as a result of a chemical reaction of aluminium powder with water is investigated. Such ceramics has a low mechanical strength. The purpose of the study was to determine various ways of producing high porosity alumina ceramics with a rather high mechanical strength and other properties significant for refractory ceramics. Some additives, both organic (Optapix) and inorganic (kaolin and silica), are used. The properties and structure of the obtained materials, such as bulk density, bending strength, porosity, pore size distribution, thermal shock resistance, depend on the grain size of raw materials, the viscosity of suspension, the type of additives and on the sintering temperature. Materials are sintered at a temperature of 1600 °C.
2019
Rice husk ash (RHA) and palm oil fuel ash (POFA) is a byproduct from agricultural waste produced thousand tonnes every year. This paper presents the use of RHA and POFA as a substitute material for quartz in fabricating an improved porcelain ceramic. The RH was thoroughly washed with distilled water in order to remove adhering soil and dust. After that it was dried in an oven at 100 oC for 24 hours. Then the dried husk was subjected to the chemical treatment; 2M HCL, 5% solid at 25 oC before calcinations to increase silica content. Untreated POFA was dried in an oven at 100 oC for 24 h. It was ground in a ball mill for 1.5 h with the revolution rate of 200 rev/min to reduce the particle size. Untreated POFA was sieved to remove the particles coarser than 50 μm. The POFA was treated by heating it at a temperature of 600 oC for 1.5 h. The mixed powder was then pressed into pellets at mould pressure (MP) 91 MPa. All the pellets were sintered at the temperature of 1100 oC for 1 h hour, ...
Journal of Asian Ceramic Societies, 2016
The use of industrial waste (by-products) as raw materials in the ceramic industry has been under study for decades due to the economical, energy, tax and environmental advantages. The specificity of the waste requires a basic characterization and technology thereof. The applicability of rice husk ash (RHA), as silica (SiO 2) source, in refractory and porous materials with potential structural, insulating and/or filtering applications was carried out by characterizing the ceramic behavior of stoichiometric mixtures of calcined alumina (Al 2 O 3) and RHA. A reaction-sintering framework can be defined in the (Al 2 O 3-SiO 2) system. The sinterability and conversion during the reaction sintering processes were studied in order to obtain mullite (3Al 2 O 3 •2SiO 2) ceramics. Also some microstructural features of the developed materials were studied in the 1100-1600 • C range. The mullitization was studied quantitatively. Partial densification was achieved (30%) and highly converted materials were obtained. The developed microstructure consisted in a dense ceramic matrix with homogenous interconnected porosity, with a narrow pore size distribution below 20 m. The developed material gives enough information for designing mullite ceramics materials with either porous or dense microstructures with structural, insulating or filtering applications employing RHA as silica source and calcined alumina as the only other raw material.
The publications of the MultiScience - XXXI. MicroCAD International Scientific Conference, 2017
Using high purity alumina and quartz powders and IG-017 bio-original additives of Igrex Ltd. the authors have developed new ceramic composite materials which can be applied in different industrial environment. The main goal was to fine a material and morphological structures of high performance ceramic composites as frames for development complex materials for extreme consumptions. For this the mixed powders of Al 2 O 3 , SiO 2 and IG-017 bio-original additive were uniaxially pressed at different compaction pressures into cylindrical shapes and were sintered in electric kiln under oxidation (1) and nitrogen (2) atmosphere. The grain size distribution of the raw materials was determined by laser granulometry. There thermo-physical properties were also determined by derivatography. The prepared and sintered specimens were tested on geometrical sizes, porosity and mechanical strength. In this work the authors present the results of their research and investigation.
Synthesis and Characterization of Porcelain Body Developed from Rice Husk Ash
2018
For a developing country like Bangladesh, waste management is an important issue. Since it is a small over-populated country , strict government regulations regarding landfills is essential. Expansion of ceramic industries is considered to be one of the potential sectors for the economic growth of Bangladesh. However, raw material cost per unit production is the prime concern for industrialists. Utilization of rice husk (RH) for industrial purposes is found to be an effective solution associated with both waste disposal and financial concerns. Since, RH is a rich source of silica, it could substitute quartz used in ceramic industries. Availability of RH in Bangladesh makes it more suitable for manufacturing applications. Hence, in the present work we focused on the synthesis and characterization of porcelain body by incorporating 25% rice husk ash (RHA) as a substitute of quartz and evaluation of structure-property relationship by means of temperature. Three different calcination te...
Effect of double sintering on the properties of porous ceramic
2008
This present work reports the fabrication of porous ceramic through thermal treatment of powder mixture of alumina and starch. The effects of double sintering on the properties of porous ceramic were investigated. The mixture was milled and then the dried powder below 63 m was sintered in powder form at 1100° C, 1200° C, 1300° C, 1400° C and 1500° C. Meanwhile, the second stage sintering at 1500° C was implemented after powder pressing. All sintering process was carried out for 2 hours. The mechanical and physical properties ...