Abstract

OCANTO, Freddy; ACOSTA, Nelkis; LINARES, Carlos Felipe  and  URBINA DE NAVARRO, Caribay. Estudio de la influencia del par aniónico no₃^- - br^- en la síntesis del sistema cancrinita - sodalita. Rev. LatinAm. Met. Mat. [online]. 2007, vol.27, n.2, pp.106-113. ISSN 0255-6952.

The influence of the anionic nitrate bromide composition in the synthesis of the cancrinite-sodalite system using different concentrations of NaOH (3, 8 and 16 M) and different NaNO₃/NaBr ratio (0 -100%) was studied. The synthesis was carried out with zeolite X at 80ºC and autogenous pressure during 40 hours. The obtained solids were characterized by: infrared spectroscopy (FT-IR), powder X-ray diffraction (XRD), elemental analysis using EDX and surface area (SA). To 100% bromide and 3 M NaOH hydroxysodalite containing unreacted zeolite X was obtained, while at 8 and 16 M NaOH bromosodalite was the final product. At 25% NaNO₃ and 3 and 16 M NaOH in the reaction gel, the bromide influence was observed because a mixture of nitrated cancrinite and bromosodalite was obtained. For other NaNO₃/NaBr ratio (50, 75 and 100% w/w) and for all the hydroxide concentrations nitrate cancrinite was obtained as the final product. These results were supported by EDX analyses. In the present work none cancrinite-sodalite intermediary phase was obtained.

Keywords : Synthesis of zeolites; Nitrate-cancrinite; Bromosodalite; Effect of the basicity.