A Potential of Vetiver Grass for Feldspar Replacement in Ceramic Processing

Abstract

Vetiver grass is one of the most common grass in Thailand. It has been grown in many locations for land erosion prevention, toxic pollutants removal, and environmental remediation.  The chemical analysis revealed that vetiver grass consisted of >50 % of K and ~20% of Si.  This data suggested that the vetiver grass is possible to replace feldspar in ceramic processing.  The thermal analysis of vetiver grass also confirmed that the vetiver grass can act as fluxing agents to form a glassy phase at low temperatures (873 K).  The effect of vetiver grass on feldspar replacement on some properties of ceramics were investigated such as density, porosity, and bending stress. The results showed that with increasing the ratio of vetiver grass the density of sample decreased from 2.20 g/cm³ (100% of feldspar) to 1.91 g/cm³ (100% vetiver grass).  The explanation is 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.  On the other hands, the bending stress decreased from 12.85 MPa (100% feldspar) to 9.07 MPa (100% vetiver grass).  In conclusion, the results proved that the vetiver grass is a good candidate to replace feldspar in ceramic processing. This means it can be one option for promoting environmental sustainability in term of waste and mining reductions.