title: Effect of ultrasound on the synthesis of low-modulus zeolites from a metakaolin.
abstract: It was studied the effect of ultrasonic processing (22kHz) of the aqueous suspension of metakaolin, sodium hydroxide and alumina with a molar ratio 2Al2Si2O7:12NaOH:2Al2O3 on the low-modulus zeolite synthesis processes. To investigate the XRD, SEM, IR, EDS had been used. It was shown that after ultrasonic processing, sodium aluminates are formed, what leads to a change in process of further synthesis. It was found that without ultrasonic processing on the stage of thermal treatment at 650°C, SOD zeolite (|Na6|[Al6Si6O24]) and sodium aluminosilicate (Na6Al4Si4O17) are synthesized. In the sample after ultrasound during thermal treatment, only sodium aluminosilicates of cubic syngony (Na6Al4Si4O17 and Na8Al4Si4O18) are formed. It was demonstrated that sodium aluminosilicates are precursors for the formation of LTA zeolite (|Na12|[Al12Si12O48]). As a result zeolitization of sodium aluminosilicates after the hydrothermal crystallization in alkaline solution, the sonicated sample contained 97wt% LTA. Without ultrasonic processing, the product of synthesis contained 50wt% SOD and 40wt% LTA.
authors.affiliation: Ivanovo State University of Chemistry and Technology, Sheremetevskiy Ave., 7, Ivanovo 153000, Russia.
authors.forename: Natalya E
authors.initials: NE
authors.lastname: Gordina
authors.affiliation: Ivanovo State University of Chemistry and Technology, Sheremetevskiy Ave., 7, Ivanovo 153000, Russia. Electronic address: valery.prokofev@gmail.com.
authors.forename: Valery Yu
authors.initials: VY
authors.lastname: Prokof'ev
authors.affiliation: Ivanovo State University of Chemistry and Technology, Sheremetevskiy Ave., 7, Ivanovo 153000, Russia.
authors.forename: Yuliya N
authors.initials: YN
authors.lastname: Kul'pina
authors.affiliation: Ivanovo State University of Chemistry and Technology, Sheremetevskiy Ave., 7, Ivanovo 153000, Russia.
authors.forename: Nina V
authors.initials: NV
authors.lastname: Petuhova
authors.affiliation: Ivanovo State University of Chemistry and Technology, Sheremetevskiy Ave., 7, Ivanovo 153000, Russia.
authors.forename: Sevil I
authors.initials: SI
authors.lastname: Gazahova
authors.affiliation: Ivanovo State University of Chemistry and Technology, Sheremetevskiy Ave., 7, Ivanovo 153000, Russia.
authors.forename: Olga E
authors.initials: OE
authors.lastname: Hmylova
keywords: LTA zeolite; Metakaolin; SOD zeolite; Sodium aluminate; Sodium aluminosilicate; Ultrasonic processing