El proceso de alteración ácida en modelos experimentales de argilización avanzada
- Autores: Ignasi Queralt Mitjans, Feliciano Plana, M. Kanazirski
- Localización: Boletín de la Sociedad Española de Mineralogía, ISSN 0210-6558, Vol. 15, Nº. 1, 1992, págs. 99-103
- Idioma: español
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Resumen
Rock alteration with alunite and pyrophyllite formation have been described in natural systems in epithermal ore deposits where acid solutions are affecting the rocks. This has induced us to carry out experiments in order to establish the effect of reacting agents and the temperature on intermediate rocks alteration. Natural alunite and pyrophyllite formation in advanced argillic alteration, wich commonly takes place by reaction of a solution with a source rock, was simulated in experiments using propilitized granodiorite rocks from Assarel ore deposits (Bulgaria) using hydrochloric and sulfuric acids as reacting solutions. Experiments were performed at two temperatures (250ºC, 350ºC) in autoclave vessels. Reaction products were identified by x-ray diffraction (XRD) procedures using powder to identify the minerals int he whole rock and oriented aggregates to characterize the clay fraction. Alunite appears in the sulfuric acid reaction at both temperatures whilst pyrophyllite only appears at high temperature associated with mixed-layer I/SM clays.
