Estimation of the Zeolite Contents of Tuffaceous Samples from the Bigadiç Clinoptilolite Deposit, Western Turkey
Variation of the NH4+-exchange and CO2-adsorption capacities with zeolite content was investigated in detail to assess the potential use of these capacities for the estimation of the zeolite contents of the samples taken from the Bigadiç clinoptilolite deposit in western Anatolia, as an alternative to the widely used semi-quantitative X-ray diffraction (XRD) technique. Samples with known clinoptilolite contents taken from 2 different zones with fine- and coarse-grained tuffs of the Bigadiç deposit were used for this purpose. Na-enriched forms of the samples were prepared by repeated ion-exchange with NaCl solutions, and NH4+-forms by repeated Na exchange followed by NH4+ exchange with NH4Cl solutions, which in turn were calcined to obtain the H-forms. NH4+-exchange capacities by Kjeldahl analyses of the NH4+-forms and CO2 adsorption isotherms in the 0 to 100 kPa range of Na- and H-forms of the samples were determined. Dubinin-Astakhov model parameters were calculated from the isotherm data.
A strong relationship exists between the experimental CO2-adsorption capacities at 100 kPa of the Na-forms and the zeolite contents of the samples. Although the Dubinin-Astakhov model represented the isotherm data quite well, the relationships between the amounts of adsorbate at saturation pressure, calculated from the model, and the zeolite contents of the samples were weaker. The strength of the relationship between NH4+ exchange capacities and zeolite contents was seen to vary with the zone of origin. There is a very strong relationship between the adsorption and ion-exchange capacities of the samples in their Na-forms taken from the fine-grained zone, indicating that either ion-exchange or adsorption capacity measurements can be used to estimate the zeolite contents of the samples taken from this zone, whereas, significant diffusion hindrance was observed against ion-exchange of hydrated cations from aqueous solutions for some samples from the coarse-grained zone. Inspection of the data pointed to systematic errors in the zeolite contents determined by a semi-quantitative XRD technique. When both zones are considered together, CO2-adsorption capacities at 100 kPa of the samples in their Na-forms can be used as a reliable measure of the zeolite content, which in turn is an important index to predict the performance of natural samples in various applications.
Key WordsClinoptilolite CO2 Adsorption Dubinin-Astakhov Isotherm Model Natural Zeolites NH4+-Exchange Zeolite Content
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- Ames LL. 1960. The cation sieve properties of clinoptilolite. Am Mineral 45:689–700.Google Scholar
- Ataman G. 1977. Zeolite occurrences in western Anatolia. Earth Sci 3:85–94 (in Turkish).Google Scholar
- Baysal O, Gündoğdu N, Temel A, Üner F. 1986. Geological investigation of the zeolite formations in Bigadiç. Hacettepe University Project Report: YUVAM. p 85–2 (In Turkish).Google Scholar
- Dubinin MM. 1975. Physical adsorption of gases and vapors in micropores. In: Cadenhead DA, editor. Progress in surface and membrane science. New York: Academic Press, p 1–70.Google Scholar
- Erdem-Şenatalar A, Sirkecioğlu A, Güray I, Esenli F, Kumbasar I. 1993. Characterization of the clinoptilolite-rich tuffs of Bigadiç: Variation of the ion-exchange capacity with pretreatments and zeolite content. In: von Balmoos R, Higgins JB, Treacy MMJ, editors. Proceedings of Ninth International Zeolite Conference. Boston: Butterworth-Heinemann. Volume 2. p 223–230.CrossRefGoogle Scholar
- Etibank. 1989. Investigation of the technological properties of Bigadiç zeolites. Etibank Project Report. 112 p (in Turkish).Google Scholar
- Flanigen EM, Mumpton FA. 1981. Commercial properties of natural zeolites. In: Mumpton FA, editor. Mineralogy and geology of natural zeolites. Washington D.C.: Mineralogical Society of America, p 165–174.Google Scholar
- Lieu K, Williford CW, Reynolds WR. 1988a. Cation exchange characteristics of Gulf Coast clinoptilolite. In: Kallo D, Sherry HS, editors. Occurrence, properties and utilization of natural zeolites. Budapest: Akademiai Kiado. p 449–461.Google Scholar
- Lieu K, Williford CW, Reynolds WR. 1988b. Comparison of wet chemistry CEC determinations. In: Kallo D, Sherry HS, editors. Occurrence, properties and utilization of natural zeolites. Budapest: Akademiai Kiado. p 541–550.Google Scholar
- Mumpton FA. 1988. Development of uses for natural zeolites: A critical commentary. In: Kallo D, Sherry HS, editors. Occurrence, properties and utilization of natural zeolites. Budapest: Akademiai Kiado. p 333–366.Google Scholar
- Sersale R. 1985. Natural zeolites: Processing, present and possible applications. In: Drzaj B, Hocevar S, Pejovnik S, editors. Zeolites. Amsterdam: Elsevier, p 503–512.Google Scholar
- Sheppard RA, Gude AJ. 1982. Mineralogy, chemistry, gas adsorption and NH4+-exchange capacity for selected zeolitic tuffs from western United States. U.S. Geological Survey Open-File Report: 82–969. 16 p.Google Scholar
- Sirkecioğlu A, Esenli F, Kumbasar I, Eren RH, Erdem-Şenatalar A. 1990. Mineralogical and chemical properties of Bigadiç clinoptilolite. In: Savaşçin MY, Eronat AH, editors. Proc International Earth Science Congress on Aegean Regions. IESCA Pub. No. 2, I:291–301.Google Scholar
- Triebe RW, Tezel H, Erdem-Şenatalar A, Sirkecioğlu A. Promising air purifications on clinoptilolite. In: Karge HG, Weitkamp J, editors. Zeolite science 1994: Recent progress and discussions. Amsterdam: Elsevier, p. 219–220.Google Scholar
- Valyon J, Papp J, Kallo D. 1981. Estimation of mordenite and clinoptilolite content in Hungarian rhyolitic tuffs. In: Sersale R, Collella C, Aiello R, editors. Recent Progress Reports and Discussion of the 5th. International Convention on Zeolites. Napoli: Giannini. p 199–202.Google Scholar
- Worrall WE. 1986. Clays and ceramic raw materials. London: Elsevier. 239 p.Google Scholar
- Yücel H, Culfaz A. 1988. Characterization of clinoptilolites of western Anatolia. In: Kallo D, Sherry HS, editors. Occurrence, properties and utilization of natural zeolites. Budapest: Akademiai Kiado. p 99–108.Google Scholar