Hydrothermal synthesis of analcime from steel slag-fly ash and its performance characterization

Abstract

In this study, geopolymers were prepared by steel slag, fly ash, and alkali activitor of sodium hydroxide and sodium silicate solution.Then the analcime was synthesized by hydrothermal methods.It is investigated the effects of different molar ratios of n(SiO2)/n(Al2O3) and steel slag/fly ash contents on the synthesis of analcime.The raw materials, intermediate products and final products were characterized by XRF, XRD, SEM, TEM and TG-DSC.The specific surface area and pore structure of the products were also investigated by BET.The results show that the analcime with relatively pure crystalline phase can be synthesized when the amount of steel slag and fly ash is 4:6, the n(SiO2)/n(Al2O3) molar ratio is 4.2 and the hydrothermal temperature is between 150℃ and 180℃.Meanwhile, the analcime products exhibited certain thermal stability.Compared with the traditional synthesis of analcime with fly ash, the addition of steel slag providing a new approach for the resource utilization of steel slag.

Keywords

• steel slag
• fly ash
• geopolymer
• hydrothermal
• analcime