SYNTHESIS OF ZEOLITE 4A FOR OBTAINING ZEOLITE 5A BY IONIC EXCHANGE FOR FULL UTILIZATION OF WASTE FROM PAPER INDUSTRY

Abstract In order to minimize environmental impact zeolite A was synthesized using waste from the paper industry. This waste is composed of cellulose, kaolin and calcium carbonate. Waste purification was carried through thermal and chemical treatment, which consisted of initial calcination, acid washing with HCl, then calcination of the solid fraction to obtain metakaolin and evaporation of the liquid fraction to obtain CaCl2. Zeolite 4A was produced by static autoclaving under hydrothermal synthesis at different temperatures, crystallization times and NaOH concentrations. As a source of aluminum and silicon metakaolin was used. The synthesis of zeolite 5A was performed by ion exchange with CaCl2. After that, the waste paper (in natura and HCl treatment) and the zeolites 4A and 5A were characterized by XDR, SEM, FTIR, AAS and thermal analysis. The temperature is a key factor in zeolite synthesis at lower concentrations allowing one to obtain zeolite 5A by ion exchange with zeolite 4A.