A clean and cheap procedure for the synthesis of zeolites is presented, using glass and luminum wastes as starting materials. The products are aluminosilicate materials with a high cation exchange capacity (CEC: 259–389.5 meq/100 g) containing 25–30% of crystalline zeolites. Since the synthesized materials are free of potentially toxic elements, they could be safely used for environmental and agricultural applications. More specifically, a material containing 30% of zeolite A has been synthesized at 60°C in one week, using NaOH as mineralizing agent. About 15% of zeolite A has been obtained at room temperature in six months. When KOH was employed, 25% of edingtonite has been produced in the final material after one week at 90°C. All the materials have been characterized for crystallinity, crystal morphology, particle size, pore size, surface area, and CEC. The whole process has been designed with the aim to recycle useful waste materials and reduce at minimum energy consumption and the production of harmful greenhouse gases.
Articolo completo: http://onlinelibrary.wiley.com/doi/10.1002/clen.201400091/abstract