Ambient-temperature conversion of metakaolin to sub-micron LTA zeolite and its copper ion removal efficiency

Abstract

Nowadays “green” processes such as room temperature processes are interested in new researches for production of practical-important solid materials. Zeolitic LTA materials are commonly prepared by hydrothermal transformation using sodium hydroxide (NaOH), sodium aluminate (NaAlO2), and sodium metasilicate (Na2SiO3) at high temperatures (95 – 100 ◦C). In this study, sub-micron zeolite LTA was prepared at ambient temperature from metakaolin which is easily obtained from kaolin mineral. The prepared materials were characterized using various methods, including XRD to identify their structure, SEM and EDX to analyze the shape and proportional components of the elements, and the N2 adsorption–desorption method to determine the surface area and pore volume. Regarding the Cu2+ ion adsorption capability of the synthetic zeolite, the experimental results revealed that the sub-micron zeolite LTA has potential applications in practice because its adsorption rate exceeds that of the commercial zeolite and the rate constant of the second–order kinetics model of the prepared zeolite was 1.7 times higher than that of the commercial zeolite.

Keywords

• lta zeolite
• metakaolin
• ambient temperature synthesis
• sub-micron size
• cu2+ adsorption