engleski

Thermal transformations of zeolite LiA(BW), (Li,Na)LTA and their derivatives obtained by mechanochemical treatment

Zeolites LiA(BW) and (Li,Na)-LTA, as well as their amorphous derivatives obtained by high-energy ball milling were heated at different temperatures (760-1150^oC) for 0.5 and 3h. The heating of both original (crystalline) and mechanochemically amorphized zeolite (Li,Na)-LTA resulted in the formation of a mixture of carnegieite (ca.50%) and gama-eucryptite (ca. 50%). at lower temperatures (760-822^oC) and mixtures of beta-eucryptite and nepheline at higher temperatures (822-1150^oC).The heating of zeolite LiA(BW) resulted the formation of gama-eucryptite at lower temperatures (760-822^oC). Mechanochemically amorphized zeolite LiA(BW) transformed to mixtures of beta- and gama-eucryptite at 760-822oC and to beta-eucryptite at prolonged time of heating (822^oC). The results obtained are discussed in terms of the influence of various factors (type of cation, present framework structure, stability of different phases) on the transformation pathways.

LiA(BW); (Li;Na)-LTA; Phase transformations

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