Adhered Zeolite Preparation on and Within a Muscovite Mica by Hydrothermal Growth

Abstract

Zeolites and other open framework materials provide a powerful tool for remediation and solidification of a range of cationic wastes (e.g. NH 4 + , Pb 2+ ) due to the combined properties of large surface area and cation exchange capacity. However, practical barriers exist to the continued expansion of their use, including handling issues related to the fine particle size, and continued ion exchange following waste adsorption. This study examines the synthesis and characterization of zeolites adhered to a muscovite mica wafer, in order to assess if practical benefit can be derived from the preparation of layered composite materials. The paper demonstrates that increased metal adsorption, as demonstrated by surface chemical composition, can be induced in regions by growth of zeolite on and within the lamellar structure of the matrix. X-ray diffraction studies suggest that a site-specific crystallization mechanism controls the zeolite type and extent of growth, thereby reducing control over the zeolites prepared. However, although increased adsorption has been introduced to the mica, the amount of zeolite added is small (<50 mg per gram of muscovite), and thus any adsorption is very limited.

Zeolitisation of pumice—microporous materials on macroporous support structures derived from natural materials

“…However, the zeolite film could only be grown at a maximum of 30-40 mg of zeolite per g of substrate, not all of which was readily available, and therefore a low cation exchange capacity was found for the overall material. 16 These findings demonstrate that materials exhibiting a much larger areas for zeolite growth must be utilized to provide efficient ion-exchange.…”

“…However, if separation is required, efficiency will be compromised either by lower binding or filtration requirements. Solutions to this issue have been examined in the literature, 9,16 but no solution has yet offered an improvement on the use of natural zeolites. For instance, separation of fine particles by froth floatation of waste loaded zeolites by addition of surfactants has been proposed, 9 but in practice this adds another level of waste and potential contamination to the system.…”

“…Preparation of zeolite on these surfaces using hydrothermal growth was examined by Johnson and Worrall. 16 The resultant film provided a fine layer of zeolite on the surface, capable of ion-exchange. However, the zeolite film could only be grown at a maximum of 30-40 mg of zeolite per g of substrate, not all of which was readily available, and therefore a low cation exchange capacity was found for the overall material.…”

Insights into Alkali-Acid Leaching of Sericite: Dissolution Behavior and Mechanism

“…Zeolites are thermodynamically metastable [31]. Their nucleation and crystal growth are strongly affected by crystallization temperature and alkali concentration [32,33]. Changes in temperature and alkali concentration will both affect the crystal growth rate and nucleation rate of zeolites.…”