Influence of Blended Activator on Microstructure, Crystal Phase and Physical Properties of Spent Catalyst Slag-Based Geopolymer

摘要

The spent catalyst slag discharged from various industrial products may be feasible as a geopolymer source material due to its rich Si and Al elemental composition and amorphous structure. In this study, spent catalyst slag-based geopolymers were fabricated using a blended alkaline activator of NaOH and sodium silicate, and the compressive strength levels of the samples were assessed by analyzing the types of phases which formed and the nano-sized microstructures. The molarity of the NaOH solution and amount of the sodium silicate in blended alkaline activator solution were varied to determine the optimum combination of these two factors so as to find the optimum mechanical properties of the geopolymer. A cubic green compact of the geopolymer was formed using a mould 5x5x5 cm in size. A water-to-solid ratio of 0.29 was used. The green specimens were cured at 70 degrees C for 24 h and were aged for 3 or 28 days at room temperature. This geopolymer has potential as a substitution material for cement for applications in building materials given that its compressive strength measurement showed values in the range of 40 similar to 85 MPa.