Zeolite A synthesis employing a brazilian coal ash as the silicon and aluminum source and its applications in adsorption and pigment formulation

• Published in: Materials research (São Carlos, São Paulo, Brazil) São Paulo, Brazil), 2013-01, Vol.16 (1), p.38-43
• Main Authors: Bieseki, L, Penha, F G, Pergher, S B C
• Format: Article
• Language: eng ; por ; spa
• Subjects: Adsorption; Aluminum; Ashes; Brazil; Coal; coal ash; ENGINEERING, CHEMICAL; MATERIALS SCIENCE, MULTIDISCIPLINARY; METALLURGY & METALLURGICAL ENGINEERING; pigment; Silicon; Synthesis; zeolite A; Zeolites
• ISSN: 1516-1439; 1980-5373; 1980-5373
• DOI: 10.1590/S1516-14392012005000144

Zeolite A was synthesised using coal ash from Sideropolis, Brazil. The synthesis was based on a standard International Zeolite Association (IZA) synthesis using coal ash as the Si and Al source. XRF 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 synthesised materials were analysed 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 h was the most crystalline, but even the product formed after 1 h proved to be better than that formed using the standard 4 h IZA synthesis. Zeolites synthesised by this method had an adsorption capacity of 120 mg/g for Ca2+, half the capacity of commercial zeolite A (300 mg/g). It was not possible to obtain blue or green pigments using the synthesised zeolite A.