Wyniki wyszukiwania - BazTech

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Synteza zeolitów z perlitu i ich zdolności sorpcyjne

Król M., Morawska J., Mozgawa W., Pichór W.

Materiały Ceramiczne

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2014

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T. 66, nr 2

129--134

PL

W pracy przedstawiono wyniki badań nad procesem syntezy materiału zeolitowego z odpadowej frakcji pylastej powstałej przy produkcji perlitu ekspandowanego. Przeanalizowano wpływ stężenia i ilości roztworu NaOH, temperatury oraz czasu syntezy na rodzaj i ilość powstałych produktów. W zależności od warunków, w jakich prowadzony był proces, zidentyfikowane na podstawie rentgenowskiej analizy fazowej (XRD) produkty to: zeolit Na-P1, zeolit X, zeolit A oraz hydroksysodalit. Obecność faz zeolitowych potwierdziły pomiary spektroskopowe w zakresie środkowej podczerwieni oraz obserwacje w mikroskopie skaningowym. Stwierdzono, że istnieje możliwość optymalnego doboru parametrów syntezy zeolitów; już po 24 h w temperaturze przynajmniej 60 °C i przy stężeniu NaOH powyżej 3,0 mol/dm3 możliwe jest efektywne przekształcenie perlitu w materiał zeolitowy. Na podstawie analizy składu fazowego (zawartość zeolitów A oraz X) oraz mikrostruktury uzyskanych próbek wyselekcjonowano te o potencjalnie wysokich zdolnościach sorpcyjnych. Wyznaczono pojemności sorpcyjne wybranych próbek. Stwierdzono, że sodowe zeolity uzyskane w procesie syntezy z perlitu ekspandowanego mogą być z powodzeniem wykorzystywane w procesach sorpcyjnych.

EN

The paper presents research in synthesis of zeolites using waste dusty fractions coming from the production of expanded perlite. The influence of concentration and amount of a aqueous solution of NaOH together with temperature and time of synthesis on the type and quantity of the resulting products was analyzed. Depending on the process conditions, zeolite Na-P1, zeolite X, zeolite A, and hydroxysodalite were the products identified by X-ray diffraction analysis (XRD). The presence of the zeolite phases has been confirmed by mid-infrared spectroscopic measurements and scanning electron microscope observations. It has been found that it is possible to optimize the synthesis parameters. The perlite dust transforms into the zeolitic material just after 24 h synthesis in the NaOH aqueous solution of concentration above 3.0 mol/dm3 at ≥ 60 °C. Basing on the content of the A and X zeolites, and the microstructure of the obtained samples, the zeolite materials of potentially high sorption capacity were selected. Cation exchange capacities of the selected samples were determined. It has been found that sodium zeolites obtained from the perlite dust can be successfully used in sorption processes.

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Low-temperature synthesis of zeolite from perlite waste — Part I: review of methods and phase compositions of resulting products

Król M., Morawska J., Mozgawa W., Pichór W.

Materials Science Poland

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2014

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Vol. 32, No. 3

503--513

EN

In this paper a review of the recent studies on the synthesis of zeolites from expanded perlite under hydrothermal conditions is presented. Attention is paid to possible outcomes of synthesis from low cost glass material, such as perlite. The study also investigates the phase composition of zeolitic materials obtained by modification of by-product derived from an expanded perlite production process. The synthesis was made using the hydrothermal method with sodium hydroxide under autogenous pressure at a temperature below 100 °C for 1 to 72 h. It was possible to obtain a zeolitic material at a temperature as low as 60 °C using 4.0 M NaOH. The X-ray diffraction pattern showed the biggest peak intensity of zeolite X with 4.0 M NaOH at the temperature of 70 °C. During synthesis at higher temperature zeolite Na-P1 (with 3.0 M NaOH at 90 °C) and hydroxysodalite (with 5.0 M NaOH at 90 °C) were obtained.

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Low-temperature synthesis of zeolite from perlite waste — Part II: characteristics of the products

Król M., Morawska J., Mozgawa W

Materials Science Poland

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2014

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Vol. 32, No. 4

526--532

EN

The paper investigates the properties of sodium zeolites synthesized using the hydrothermal method under autogenous pressure at low temperature with NaOH solutions of varying concentrations. During this modification, zeolites X, Na-P1 and hydroxysodalite were synthesized. The synthesis parameters, and thus, phase composition of resulting samples, significantly affected the specific surface area (SSA) and cation exchange capacity (CEC). SSA increased from 2.9 m2 /g to a maximum of /g, while CEC rose from 16 meq/100 g to a maximum of 500 meq/100 g. The best properties for use as a sorbent were obtained for perlite waste modified with 4.0 M NaOH at 70 °C or 80 °C.