Abstract

OCANTO, Freddy; FLORENZANO, Elizabeth  and  LINARES, Carlos F. Influence of basicity and chromate-bromide anionic composition in the synthesis of the cancrinite-sodalite system. Rev. LatinAm. Metal. Mater. [online]. 2013, vol.33, n.1, pp.131-137. ISSN 0255-6952.

The influence of the basicity and anionic composition (CrO₄^2- and Br^-) was studied in the synthesis of chromate-cancrinite and bromosodalite-type zeolites. The synthesis was carried out starting from zeolite X as a source of Si and Al, different concentrations of NaOH (8, 12 and 16 M) and variable weight proportions [NaBr / (NaBr + K₂CrO₄)] = 0.00, 0, 25, 0.50, 0.75 and 1.00, so that the total grams was 1,5 g. The synthesis was performed at 80° C and autogenous pressure for 40 h. Obtained crystals were characterized by Fourier transformed infrared spectroscopy (FT-IR), powder X-ray diffraction (XRD) and qualitatively by the color of the products obtained. Results showed that the bromosodalite was obtained at 100 and 75% Br^- for all used base concentrations; at 50% Br^-, a mixture of chromate-cancrinite and bromosodalite was determined. When 25 and 0% Br^- was used, chromate-cancrinite was only determined. These results infer that obtained products for this particular anion pair (chromate-cancrinite or bromosodalite) depends on the compositions by weight of each anion in the reaction gel and not the employed base concentration.

Keywords : basicity; bromosodalite; chromate-cancrinite; zeolites.

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