Characterization of a few Mexican clays

The characterization of a few Mexican clays with chemical treatmentfor possible application as catalysers is shown. The natural clays are treatedwith H₂ SO₄ , HF, F₃ CSO₃ H, ClSO₃ H, HClO₄ and their behavior in reactions with some alcoholswas recorded. The analysis were made before and after using the clays as catalysers.The clays were characterized by Mössbauer spectroscopy, X-ray diffraction,X-ray fluorescence analysis, and differential thermo analysis. The predominantmineral species are: montmorillonite, christobalite and quartz. The main elementsare: Si, Al, Fe, Ca, K, etc. The Mössbauer results show mainly a paramagneticdoublet of Fe₃₊ . The clays behave similarly as described in theliterature.