Nucleation and growth kinetics of analcime from precursor Na-clinoptilolite
2000; Mineralogical Society of America; Volume: 85; Issue: 10 Linguagem: Inglês
10.2138/am-2000-1001
ISSN1945-3027
AutoresRichard T. Wilkin, H. L. Barnes,
Tópico(s)Minerals Flotation and Separation Techniques
ResumoThe kinetics and mechanism of analcime formation from precursor Na-clinoptilolite (Cpt-Na) and Na-mordenite (Mor-Na) were investigated from 125-225 °C, pressures up to 34.5 MPa, and pH = 9.2-10.7. By using batch and flow-through experimental methodologies, compositions of solids and solutions were monitored to track reaction progress, determine rates of analcime nucleation and growth, and evaluate the rate dependency of these processes on aqueous supersaturation. Analcime formation proceeds via a clinoptilolite (or mordenite) dissolution→analcime nucleation→analcime growth sequence. Synthetic analcime crystals are similar in morphology (trapezohedron to cubic trapezohedron) and composition (Si/Al = 2.1-2.7) to sedimentary analcimes formed during the lowgrade alteration of crustal rocks, evidence that the experimental reaction mechanism is similar to that in natural environments.
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