Transformation of Indonesian Natural Zeolite into Analcime Phase under Hydrothermal Condition

Abstract

Abstract. Natural zeolite is abundantly available in Indonesia and well distributed especially in the volcano area like Java, Sumatera, and Sulawesi. So far, natural zeolite from Klaten, Central Java is one of the most interesting zeolites has been widely studied. This research aims to know the effect of seed-assisted synthesis under a hydrothermal condition at 120 °C for 24 hours of Klaten's zeolite toward the structural change and phase transformation of the original structure. According to XRD and XRF analysis, seed-assisted synthesis through the addition of aluminosilicate mother solution has transformed Klaten's zeolite which contains (mordenite and clinoptilolite) into analcime type with decreasing Si/Al ratio from 4.51 into 1.38. Morphological analysis using SEM showed the shape changes from irregular into spherical looks like takraw ball in the range of 0.3 to 0.7 micrometer. Based on FTIR data, structure of TO4 site (T = Si or Al) was observed in the range of 300-1300 cm -1 and the occupancy of Brønsted acid site as OH stretching band from silanol groups was detected at 3440-3650 cm -1 . Nitrogen adsorptiondesorption analysis confirmed that transformation Klaten's zeolite into analcime type has decreased the surface area from 55.41 to 22.89 m 2 /g and showed inhomogeneous pore distribution which can be classified as micro-mesoporous aluminosilicate materials.

Conventional and Microwave Hydrothermal Synthesis and Application of Functional Materials: A Review

“…In addition, the type of mineralization agent also has a great influence on the quality and growth rate of the crystal. Studies have shown that the use of acids, such as HCl, H 2 SO 4 , H 3 PO 4 , HNO 3 , and HCOOH, as mineralizers can reduce the crystal growth temperature to below 300 °C, thus allowing the use of relatively simpler autoclaves [51,52]. Tani et al [53] summarized the effect of mineralizers on ZrO 2 crystallization using the hydrothermal method as shown in Table 1.…”

Hydrothermal Conversion of Fly Ash into Monomineralic Zeolite Synthesis for Biodiesel Production

“…The well-established procedure involves alkali fusion from CFA followed by hydrothermal treatment to achieve a desired X-type zeolite structure [2]. For instance, the conversion of Indonesian zeolite into analcime (ANA) form was conducted under hot-water conditions [3] leading to zeolites with high crystallinity. Sandoval et al suggest that ANA can be manufactured from natural clinker [4].…”