Journal
APPLIED CLAY SCIENCE
Volume 24, Issue 1-2, Pages 79-91Publisher
ELSEVIER
DOI: 10.1016/S0169-1317(03)00150-9
Keywords
heulandite; clinoptilolite; treatment; surface modification
Ask authors/readers for more resources
Three HEU-type zeolites from Armenia, Georgia and Greece formed from alteration of volcanic glass were treated with dilute KOH and subsequently either reacted with 6N HCl or heated at 700 degreesC. The raw materials and the reaction products were examined with X-ray diffraction (XRD), infrared spectroscopy (FTIR) and N-2 gas adsorption. The cation exchange capacity (CEC) of the zeolites was also determined. The Greek zeolite has thermal characteristics typical for heulandite I, while the Armenian and Georgian zeolites have characteristics typical for heulandite III (clinoptilolite). KOH treatment increased slightly specific surface area (SSA) and microporosity due to dissolution of amorphous material. Acid treatment increased significantly both specific surface area and microporosity, as determined by t-plots, and decreased CEC This is attributed to partial dissolution of both Si-tetrahedra and free linkages, which yielded secondary micropores and destroyed specific exchange sites of the HEU-type zeolites. Heating decreased both specific surface area and microporosity. (C) 2003 Elsevier B.V. All rights reserved.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available