Characterization of MgO and Al2O3 based Refractory waste as partial replacement for Fly ash based Geopolymer

Abstract

Green process is a manufacturing technologies method without harming the environmental, one of the green process is reclaiming and reuse the manufacturing waste into applicable products. Geopolymer is one of the examples of green process products. Geopolymer are a material from synthesized aluminosilicate and alkali silicate that formed polymeric SiO4 and AlO4 structure. Geopolymer can be applicated for building or refractory material. Aluminosilicate material such as fly ash is used for Geopolymer precursor. In this study, fly ash as precursor is substituted by magnesium oxide (MgO) and aluminum oxide (Al2O3)-based refractory waste. It was then activated by activator consist of sodium hydroxide (NaOH) and Na2SiO3 (water glass). Results shown that the compressive strength of Al2O3 refractory waste based geopolymer are generally higher than MgO refractory waste based geopolymer. The result showed an addition of Al2O3 refractory waste improved the compressive strength of geopolymer specimen. XRD and FTIR characterization conducted to analyse the morphological compound and bonding of resulting geopolymer. The substance that contained in MgO and Al2O3 refractory based geopolymer are Quartz, Periclase, Corundum and Albite. FTIR results shows the siloxo and sialate bond as proof of geopolymerization has successfully occured.