Síntese da zeólita A utilizando diatomita como fonte de sílicio e alumínio

Abstract

The zeolite A is a typical synthetic zeolite widely used in industries such as ion exchanger in detergent formulation. The diatomite, silica rich material (about 80%), is used in several industrial sectors such as filtering agent. This work presents the synthesis of zeolite A using diatomite as a source of SiO2 and Al2O3. The employed SiO2/ Al2O3 ratios were 2 and 1.5. All samples were characterized by XRD, N2 adsorption and SEM. It was possible to synthesize pure zeolite A with 51% crystallinity after 2 h of crystallization. Higher crystallization times, regardless of the Si and Al ratio led to formation of sodalite phase. In the second synthesis with SiO2/ Al2O3 ratio = 1.5, through the separation process, it was observed that the formation of zeolite A is from agglomerates of particles of diatomite, and conversely to longer times favor the dissolution of diatomite favoring forming the phase sodalite from the zeolite crystals A.