Formation of nanocrystalline zeolites from industrial waste materials under strong alkaline conditions at short reaction times and low temperatures

• Applicant: Professor Dr. Josef-Christian Buhl
• Subject Area: Mineralogy, Petrology and Geochemistry
• Term: from 2011 to 2015
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 191172577

The project deals with the development of new models for the insertion of paper sludge combustion ash and silicate rich filter residues from waste water reconditioning for zeolite synthesis using a low temperature alkaline digestion process. The results, worked out up to now, yield to zeolites LTA and X in a two step reaction process of waste materials digestion followed by gel crystallization. Preparation of the Ca-form of the zeolites under insertion of paper sludge combustion ash was also successful. In contrast, multiphase products were observed under a direct conversion process, but these investigations led to interesting new questions. Answering the question of (1) an influence of the early very short reaction period, (2) an alkaline activation of the starting waste materials at room temperature and (3) the role of the otimal time of admixing aditives like NaAlO2 have to be mentioned as the subject of this present additional research proposal. Three new reaction series are planned and basic knowledge on an optimal alkaline transformation of waste materials into valuable zeolites at only 60°C is expected from the results.

• DFG Programme: Research Grants