Fabrication of Eco-Green Brick by Using of Vetiver Grass as Feldspar Replacement
Vetiver grass is a widespread plant in Thailand. It has been used in several applications such as land erosion prevention, toxic pollutants removal, and environmental remediation. The chemical analysis provided that it mainly contained of >50% of potassium and ~20 wt% silicon. Since, the main element is potassium, then it is likely to be used as feldspar replacement in ceramic processing. The thermal analysis of vetiver grass also revealed that the vetiver grass can act as fluxing agents to form a glassy phase at low temperatures (600°C). The effect of vetiver percentage in ceramic processing on some physical and mechanical properties of ceramics were examined including, firing shrinkage, density, porosity, and bending stress. The results showed that with increasing the ratio of vetiver grass the density of sample decreased from 1.7 g/cm3 (without vetiver grass) to 1.1 g/cm3 (30 wt% of vetiver grass) at 600°C of firing temperature. The explanation was that during the firing process vetiver grass can generate CO2 from hydrocarbon decomposition, this CO2 created pores inside the sample, then the density was decreased and pore volume also increased. Meanwhile, the bending stress decreased from 3.6 MPa (without vetiver grass) to 0.5 MPa (30 wt% of vetiver grass) at 600°C of firing temperature. In summary, the results proved that the vetiver grass is a good candidate to be feldspar replacement in ceramic processing. In the other words, it can be one option for promoting environmental sustainability in term of waste and mining reductions.
Yunqiu He, Ramesh K. Agarwal and Jean-Jacques Delaunay
T. Threrujirapapong et al., "Fabrication of Eco-Green Brick by Using of Vetiver Grass as Feldspar Replacement", Materials Science Forum, Vol. 890, pp. 391-395, 2017