scholarly journals Optimisation of the Physical Properties of Rice Husk Ash in Ceramic Materials Using the Response Surface Methodology

2021 ◽  
Vol 49 (1) ◽  
pp. 23-30
Author(s):  
Asotah Wisdom ◽  
Udochukwu Mark ◽  
Elakhame Zeberu ◽  
Abraham Adeleke

Optimisation of the physical properties of rice husk ash (RHA) in ceramic materials was carried out using Response Surface Methodology. The independent variables, namely the firing temperature and residue content, were statistically combined in a Central Composite Design with the effects on water absorption, linear shrinkage, bulk density, apparent porosity and apparent specific gravity determined. Physical and microstructural analyses were carried out to obtain information on the processes that occurred within the ceramic materials. The results obtained were analysed to determine the optimum physical properties of the ceramic materials within the range investigated. The residue content had a significant influence (at 95% confidence level) on the bulk density, water absorption, apparent porosity and apparent specific gravity but not on the linear shrinkage. The firing temperature had a more significant effect on the linear shrinkage than on the residue content, so that when elevated it contributed to an increase in linear shrinkage. The optimum residue content and firing temperature to enhance physical properties within the range investigated were 5.85% RHA and 1029.64°celsius, respectively. These optimal conditions are expected to produce a ceramic material with a bulk density, linear shrinkage, apparent porosity, water absorption and apparent specific gravity of 1.64 g/cm3, 0.29%, 0.29 g/cm3, 18.26% and 2.11, respectively with a composite desirability of 100%.

2018 ◽  
Vol 777 ◽  
pp. 465-470
Author(s):  
Sutas Janbuala ◽  
Mana Eambua ◽  
Arpapan Satayavibul ◽  
Watcharakhon Nethan

The objective of this study was to recycle powdered marble dust to improve mechanical properties and thermal conductivity of lightweight clay bricks. Varying amounts of powdered marble dust (10, 20, 30, and 40 vol.%) were added to a lightweight clay brick at the firing temperatures of 900, 1000, and 1100 °C. When higher quantities of powdered marble dust were added, the values of porosity and water absorption increased while those of thermal conductivity and bulk density decreased. The decrease in apparent porosity and water absorption were also affected by the increase in firing temperature. The most desirable properties of the clay bricks were obtained for the powdered marble dust content of 40 vol.% and firing temperature 900 °C: bulk density of 1.20 g/cm3, compressive strength 9.2 MPa, thermal conductivity 0.32 W/m.K, and water absorption 22.5%.


2014 ◽  
Vol 608 ◽  
pp. 47-61
Author(s):  
Nonglak Meethong ◽  
Wanwisa Pattanasiriwisawa ◽  
Weenawan Somphon ◽  
Waraporn Tanthanuch ◽  
Sutham Srilomsak

Dan Kwian, Sukhothai and Ratchaburi pottery clays are economically important pottery clays. They are well known in the Thai ceramic society for making Dan Kwian pottery, Sawankhalok pottery and Dragon jars, respectively. There have been several studies of these pottery clays. However, few of them used statistics to analyze their results. This work is a comparative study of the compositions and properties of these three pottery clays using statistical software to analyze the results. Results show that the major components of these pottery clays are SiO2 and Al2O3. The Modulus of Rupture (MOR) of each pottery clay fired at 700°C are not significantly different. Sukhothai pottery clay fired at 900°C has a higher MOR and bulk density while its porosity, water absorption and apparent specific gravity are less than those of the Dan Kwian and Ratchaburi pottery clays fired at the same temperature. Additionally, the current study developed regression equations for estimating the properties of all pottery clays under study. Finally, it was found that the L*, a*, b* and reflectance spectra of all pottery clays increased when firing temperature was increased from 700 to 900°C.


Author(s):  
Emmanuel K. Asare ◽  
Samuel Sefa-Dedeh ◽  
Emmanuel Ohene Afoakwa ◽  
Esther Sakyi-Dawson ◽  
Agnes S. Budu

Central composite rotatable design for k = 3 was used to study the combined effect of feed moisture (12-44%), cowpea concentration (0-20%) and groundnut concentration (0-10%) on the physical and functional properties of extruded sorghum-legume blends in a single screw extruder using response surface methodology. Product expansion ratio, bulk density, total colour change, water absorption capacities at 27°C and 90°C and swelling capacities were determined on the products using standard analytical methods. Expansion ratio, bulk density and total colour of extrudates from the sorghum-legume blends decreased with increasing feed moisture. Increasing the concentration of legumes in the product increased the water absorption capacities at 27°C and 70°C and increased swelling capacities due to the gel forming ability of the macromolecules (proteins and starch) in the products and availability of hydrophilic groups to bind water molecules, thus enhancing the functional properties of the blends. Models developed for the indices gave R2-values ranging from 61.6% (for water absorption capacity at 27°C) to 89.9% (for bulk density) with insignificant lack of fits indicating the adequacy of the model in explaining the data. The optimal conditions noted for producing the puffed extruded snack products with better physical properties and functional characteristics from sorghum-groundnut-cowpea blends were at 16-18% feed moisture, 14-16% cowpea and 6-8% groundnut additions.


2020 ◽  
Vol 55 (1) ◽  
pp. 43-52 ◽  
Author(s):  
NB Bohara ◽  
DB Ghale ◽  
YP Chapagain ◽  
N Duwal ◽  
J Bhattarai

Effect of firing temperature on some physico-mechanical properties of ten brick samples, those were composed by feldspars, quartz, alumina-rich spinel, primary mullite and hematite phases, was investigated in accordance with ASTM standards. The brick samples fired between 700° to 1100° C showed 11-23 % water adsorptivity (WA), 19-37 % apparent porosity (AP) and 1.50-1.65 g/cm3 bulk density (BD) indicate good physical properties. The maximum compressive strength (CS) of the fired-bricks at 950° to 1000° C was found to be between 15.6 and 17.1 MPa. At 700°-1000° C firing temperatures, the CS of these bricks is found to be increased exponentially with decreasing of both WA and AP, however it is found to be increased with increasing the BD. Consequently, it can be said that there is good correlation between mechanical and physical properties of the fired-brick samples up to the firing temperature of 1000° C. Bangladesh J. Sci. Ind. Res.55(1), 43-52, 2020


Sign in / Sign up

Export Citation Format

Share Document