Synthesis and research of the structural properties of zeolites synthesized from the NaOH+H2O+A* (A*= SiO2, Al) system in an alkaline environment (pH > 10)

Abstract

In this paper we present the synthesis of Zeolitesthrough the obtaining of a gel composed forthe mixture of alkaline and aluminosilicate solutes.We studied the kinetics of the structurationof zeolites taking into account the reactions A:NaOH+H2O+SiO2 and B: NaOH+H2O+Al. Thevalues of concentration used on each one of thesesolutes were 4.2 g (NaOH), 60- 20 ml (H2O forthe solutes A and B respectively), 6.0 g (SiO2) y 1,7(Al). For the resulting gel, which was gotten whenadding in a slowly way the solute B to the A one, weobtained a Ph equals 14. The synthesized zeoliteswere under thermic treatments of 120°C per cyclesfrom 8 to 10 hours. The structural properties withthe identification of the growing phases were studiedthrough the technic of X- ray diffraction changing2q in the interval 5-60°. From the spectrums ofXRD we observed a mainly predominance of thecrystal phase in the composition of Zeolita with anamorphous component. The presence of phasescoming from other minerals which have been theproducts of the reaction is reflected in the synthesisof the samples. We studied the morphology ofthe surface through scanning electron microscopy(SEM). Based on SEM images it is seen that someareas of the surface are led by isolated grains andcharacterized for values in the size of the grain atabout 20 mm.