The objectives of present study were to investigate the effects of synthesis parameters on characterization of W type zeolite crystals and its intergrowths with other types of zeolites. Crystal size and purity (crystallinity) of W type zeolite are significantly affected by gel parameters (water content, silicone module, and alkalinity). In this paper, effects of gel parameters on synthesis and characterization of W type zeolite were investigated. Highly pure and crystalline W type zeolite was synthesized by Al2O3: 6.4 SiO2: 5.6 K2O: 164.6 H2O molar gel composition at T=165 °C for 72 h. Effect of excess alkalinity in mono cation (K) - SiO2 - Al2O3¬ gel composition system on nano particle size and purity (crystallinity) of the product was also studied. Experiments were carried out using these levels of alkalinity: 21.4, 29.4, and 51.9; silicone module: 5.0, 6.4, and 10.0; water content: 16.5, 25.7, and 32.9; and excess alkalinity: from 0.65 to 3.33. The resultes shows that by increasing silicone module at high alkalinity, crystallinity and crystal size of the synthesized zeolite increases, while at low alkalinity, its crystallinity and crystal size decreases. Also, decreasing alkalinity at low silicone module increases crystallinity and decreases crystal size, while at high silicone module, both decreases. Finally, by increasing water content at all silicone module and alkalinity values, crystallinity and crystal size of W type zeolite increase. Excess alkalinity was found as a key factor that should be adjusted in the range of 0.7-1.0 for synthesis of pure crystals of W type zeolite.
کلید واژگان :W type zeolite, Gel parameters, Optimum gel compositions, Crystallinity, Nano particles size
ارزش ریالی : 600000 ریال
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