Print version ISSN 1516-1439
BIESEKI, Lindiane; PENHA, Fábio Garcia and PERGHER, Sibele Berenice Castellã. Zeolite A synthesis employing a brazilian coal ash as the silicon and aluminum source and its applications in adsorption and pigment formulation. Mat. Res. [online]. 2013, vol.16, n.1, pp. 38-43. Epub Oct 26, 2012. ISSN 1516-1439. http://dx.doi.org/10.1590/S1516-14392012005000144.
Zeolite A was synthesized using the coal ash from Siderópolis/RS - Brazil. The synthesis was based on a standard IZA synthesis using coal ash as the Si and Al source. XRF analysis showed that the coal ash has a Si/Al ratio of 1.52, which is close to the Si/Al ratio required to produce zeolite A (1.0). The synthesized materials were analyzed by XRD, SEM and N2 adsorption. More crystalline materials were obtained during synthesis when an additional treatment was applied at a temperature of 353 K at the dissolution of NaOH step. The product formed after 4 hours was the most crystalline, but even the product formed after 1 hour proved to be better than that formed using the standard 4 hours IZA synthesis. The zeolites synthesized by this method had an adsorption capacity of 120 mg.g-1 for Ca2+, half the capacity of commercial zeolite A (300 mg.g-1). It was not possible to obtain blue or green pigments using the synthesized zeolite A.
Keywords : zeolite A; coal ash; adsorption; pigment.