Study Of FAU Zeolite Synthesized From Coal-series Kaolin

Both X and Y zeolite are cubic faujasite zeolite.They could be used widely inpetrochemical field as catalyst.But the use of the FAU zeolite was limited because of thehigh price of FAU zeolite. There are abundant and high-class coal-series kaolin inChina.They could be used in the synthesis process of zeolite as ideal raw material bysome simple pretreatment.In the paper,coal-series kaolin was used as raw material to synthesize13X zeolitewith microwave-assisted heating.And the growth process of13X zeolite synthesizedwas researched.Then the influencing factors of Y zeolite synthesis from coal-serieskaolin was studied. hydrothermal synthesis was used in the process and the directingagent was also added to the synthesis solutions.Finally,the process conditions of Yzeolite synthesized at pilot-scale using coal-series kaolin was studied.The samples werecharacterized by XRD, FTIR,SEM,static water absorption and elemental analysis.Andthe main results achieved were as follows:(1)13X zeolite crystal began to appear at55min; and at75min the crystal growthcompletely; the crystal would begin to transform from13X zeolite to P zeolite at150min.(2) The optimum conditions of Y zeolite synthesized were stirring6h,and ageing2h at323.15K,then crystallizing9h at373.15K. In these conditions,Y zeolite could besynthesized with high crystallinity and uniform size.(3) By adjusting the composition ratio of reaction system,the silica-alumina molarratio of Y zeolite would be improved to4.56.(4) The results of Y zeolite synthesized were nearly consistent between thepilot-scale and laboratory research.The optimum crystal time was9h.And the Y zeoliteproduct had complete crystalline form, uniform particle size about1μm, low impuritycontent and high crystallinity.