The structural analysis and surface morphology of quartz has been studied. Quartz has long been known to be a source of silica. X-ray fluorescence (XRF), X-ray diffraction (XRD) and scanning electron microscopy (SEM) were used to observe the surface and internal structure of the quartz. The results among other things revealed that the quartz consist of mainly silica (SiO 2 ), with crystalline structure, microscopic examination showed that the quartz has a porous cellular structure and consists of irregular-shaped particles. This study implies that quartz is good candidate for various applications by ceramic industries.

Rice Husk Ash (RHA) is a by-product of the agricultural industry which contains high amount of silica. Active silica from RHA has been used progressively to substitute quartz in a porcelain composition and the effect this substitution in relation to temperature on physical and mechanical properties has been investigated. It was found that progressive substitution of RHA in a porcelain composition resulted in early vitrification of the mixture. The compressive strength was highest and the porosity was the least at a temperature of 1200°C on 20wt% substitution of RHA. The improvement in the properties could be attributed to sharp changes in the microstructural features as a result of increase in mullite and glassy phase simultaneously. Hence the extension of study on microstructure and morphology has influence on the physical and mechanical properties.

The treated palm oil fuel ash (POFA) is used as a substitute material in producing an improved porcelain ceramics. Most of the POFA is posed as waste in landfills, causing environmental and other problems. The POFA is grounded in a ball mill until the particle size is reduced to about 50 μm. Then it is heated at a temperature of 600 oC for 1.5 h in an electric furnace. About 5 wt% to 25 wt% of POFA is used to substitute quartz in porcelain composition. The mixed powder is then pressed into pellets at pressure of 91 MPa. All the pellets are sintered at a temperature of 1000 oC, 1100 oC, 1200 oC and 1280 oC for 2.0 h soaking times. It is found that the highest compressive strength, 45 MPa is obtained at 15 wt% of POFA and sintered at 1100 oC. The improvement in the properties could be attributed to the changes in the microstructural features as a result of an increase in mullite and cristobalite simultaneously.

Palm oil fuel ash (POFA) is a by-product from agricultural waste produced thousand tonnes every year. This paper presents the use of treated POFA as a substitute material for quartz in fabricating an improved porcelain ceramic. Untreated POFA was dried in an oven at 100 oC for 24 h. Then, it was ground in a ball mill for 1.5 h with the revolution rate of 200 rev/min to reduce the particle size. Next, it 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 of 31 MPa, 61 MPa, 91 MPa and 121 MPa. All the pellets were sintered at the temperature of 1100 oC for 2 h soaking time. It was found that the highest compressive strength of 34 MPa is at 15 wt% POFA and mould pressure of 91 MPa. The increment in the strength could be attributed from the changes in the microstructural features as a result of an optimum applied pressure.

RHA has become an important competitive material for preparation of silicon compounds due to high surface area, high grade of amorphous form silica and fine particle sizes. The effect of mould pressure (MP) and substitution of quartz by RHA on bulk density and compressive strength of porcelain body is investigated. RHA is used as a substitute for quartz with different replacement levels (0 wt% - 25 wt%). The samples are pressed into pellets at a mould pressure of 31 MPa, 61 MPa, 91 MPa and 121 MPa. All the pellets are sintered at the temperature of 1200 °C for 2 hours soaking time and at a heating rate of 5 °C per minute. The bulk density and compressive strength are measured at the highest value of 2.42 g/cm3 and 39 MPa for the sample pressed at 91 MPa with the substitution of 20 wt% RHA. The improvement in the properties could be attributed to the sharp changes in the microstructural features as a result of an increase in mullite and glassy phase simultaneously.