Synthesis and characterization of clinoptilolite

Güvenir, Özge
Clinoptilolite is the most abundant zeolite mineral in nature. In this study a reproducible synthesis recipe for clinoptilolite was established and the limits of the crystallization field were developed by changing synthesis parameters such as temperature, composition and the nature of reactants. Clinoptilolite was reproducibly synthesized as a pure phase and in high yield at 140oC using a benchmark batch composition of 2.1 Na2O:Al2O3:10SiO2:110.1 H2O. Clinoptilolite was crystallized from 10wt% or 28wt% seeded systems while it was not formed if no seeds were present. Clinoptilolite was also crystallized as a pure phase when the cation in the benchmark batch composition was Na,K mixture, or when alkali salts such as carbonates or chlorides were used besides alkali hydroxides, or when the SiO2/Al2O3 ratio was in the range of 10-12. Clinoptilolite was still crystallized as a single phase when alkali hydroxides in the batch were reduced by 20%. With the benchmark batch composition, clinoptilolite was crystallized in pure phase form at 100oC, 120oC, 140oC and 160oC while synthesis at 175oC resulted in the formation of pure mordenite. At 140oC clinoptilolite was crystallized together with Linde L when cation in the benchmark composition is only potassium. Phillipsite crystallized together with clinoptilolite at SiO2/Al2O3 ratio of 8 to 9. At SiO2/Al2O3 ratios of 6 or 4, phillipsite or analcime was formed as pure phase respectively. When the alkali hydroxides in the batch was increased by 20%, sanidine was formed. Use of reactive aluminosilicate gels enhanced the formation of clinoptilolite while attempts to use mineral raw materials were unsuccessful. For both Na and (Na,K)-clinoptilolite, Si/Al ratio of products were greater than four. Thermal stability of synthetic clinoptilolites were comparable with natural clinoptilolite and potassium ion increased thermal stability of


Preparation of lead zirconate titanate (Pb(Zr0.52Ti0.48)O-3) by homogeneous precipitation and calcination
Tas, AC (1999-06-01)
Preparation of phase-pure PZT (Pb(Zr0.52Ti0.48)O-3) powders was achieved, in the presence of urea (CH4N2O), by homogeneous precipitation. Aqueous solutions of PbCl2, ZrOCl2. 8H(2)O, and TiCl4 were used as the starting materials in the synthesis of phase-pure PZT powders. Phase evolution behavior of precursor powders was studied by powder X-ray diffraction (XRD) in air, over the temperature range of 90 degrees to 750 degrees C. The morphology of the formed powders was studied by scanning electron microscopy ...
TAS, AC; AKINC, M (Wiley, 1994-11-01)
The crystal structures of the high-temperature forms of light lanthanide pyrosilicates (disilicates), i.e., (La-to-Sm)(2)Si2O7, have been studied with powder X-ray diffraction on the quenched samples. These compounds have monoclinic structures with the space group P2(1)/n rather than orthorhombic structures. In the research of the last two decades, the smallness of the monoclinic angles (90.1 degrees-91 degrees) has possibly obscured the revelation of the true structural nature of these compounds. New XRD p...
SANLI, O; KISAKUREK, D (1992-03-01)
Thermal decomposition of bis(4-bromo-2,6-dichlorophenoxo)-(N,N,N',N'-tetramethylethylenediamine)copper(II) complex in toluene, bis(4-bromo-2,6-dichlorophenoxo)(N,N-dimethylformamide)copper(II) complex in N,N-dimethylformamide and bis(4-bromo-2,6-dichlorophenoxo)dimethyl sulfoxide)copper(II) complex in dimethyl sulfoxide was achieved at 70-degrees-C. 4-Bromo-2,6-dichlorophenol derivatives prefer 1,4-addition to 1,2-addition, leading to highly linear polymers irrespective of the substituted ligands. The compl...
Preparation of lead zirconate titanate (Pb(Zr0.52Ti0.48)O-3) by homogeneous precipitation and calcination
Oren, EE; Tas, AC (1998-05-06)
Aqueous solutions of lead chloride (PbCl2), zirconium oxychloride (ZrOCl2.8H(2)O) and titanium tetrachloride (TiCl4), in appropriate volumetric amounts, were used as the starting materials in the synthesis of phase-pure Pb(Zr0.52Ti0.48)O-3 powders. Preparation of the phase-pure PZT powders were achieved, in the presence of urea (CH4N2O), by the chemical powder synthesis route of homogeneous precipitation.
An archaeometric application to a group of early Ottoman ceramics from İznik
Kırmızı, Burcu; Göktürk, Emine Hale; Department of Archaeometry (2004)
This study investigates the physical, mineralogical and chemical characteristics of a group of pottery sherds that are mostly Miletus-ware ceramics, belonging to the Early Ottoman period and excavated during 2003 season, from the The sherds examined are mostly characterized by cobalt-blue designs which are occasionally coupled with black, green and purple paintings. After grouping the sherds according to their stylistic and color differences; petrographic, X-ray diffraction, scanning electron microscope cou...
Citation Formats
Ö. Güvenir, “Synthesis and characterization of clinoptilolite,” M.S. - Master of Science, Middle East Technical University, 2005.