Kaunas University of Technology, Faculty of Civil Engineering and Architecture, Studentų g. 48, Kaunas 44249, Lithuania.
Kaunas University of Technology, Faculty of Mathematics and Natural Sciences, Studentų g. 52, Kaunas 44249, Lithuania.
Ultrason Sonochem. 2021 Apr;72:105426. doi: 10.1016/j.ultsonch.2020.105426. Epub 2020 Dec 24.
The fine powdered silica by-product of processing of aluminum fluoride (fertilizer plant, Lithuania) was used for zeolite synthesis as silica and aluminum source. The effect of sonication time and the time of hydrothermal synthesis on crystallinity of the synthesized zeolite were studied. This allowed the transformation of the by-product to the mixture of Na-P zeolite and Na-X zeolite. It was determined that ultrasonic-assisted hydrothermal action effected the "diamond" shape formation of Na-P zeolite with clear crystal edges. Na-P zeolite had the morphology of pseudo-spherical forms constituted by small plates when hydrothermal treatment (without sonication) was use for the preparation of zeolites. Moreover, it was determined that ultrasonic-assisted hydrothermal method effected a reduction in the crystal size compared with the zeolites which were synthesized only by using hydrothermal synthesis. The total amount of zeolites as high as 88-93% was achieved after 24 h of hydrothermal treatment followed or unfollowed by sonication. By using longer duration (20 min) of ultrasound pretreatment it is possible to reduce the duration of hydrothermal synthesis: from 24 h to 12 h of hydrothermal treatment. In this case, similar results of total amount of zeolites were detected. In the present work, low-cost raw materials, such as silica by-product have been investigated for the production of zeolites.
加工氟化铝（立陶宛化肥厂）过程中产生的细粉末状硅酸钠副产物被用作沸石合成的硅和铝源。研究了超声时间和水热合成时间对合成沸石结晶度的影响。这使得副产物转化为 Na-P 沸石和 Na-X 沸石的混合物。确定超声辅助水热作用影响了 Na-P 沸石的“钻石”形状形成，具有清晰的晶边。当使用水热处理（无超声）制备沸石时，Na-P 沸石的形态为由小板构成的拟球形形式。此外，还确定与仅通过水热合成合成的沸石相比，超声辅助水热法会降低晶体尺寸。在水热处理 24 小时后，无论是在超声处理之后还是之前，都可以达到高达 88-93%的总沸石量。通过使用更长时间（20 分钟）的超声预处理，可以减少水热合成的时间：从 24 小时减少到 12 小时的水热处理。在这种情况下，检测到总沸石量的相似结果。在本工作中，研究了低成本的原料，如硅酸钠副产物，用于生产沸石。
