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Combustion treatment of Co2+ and Cs+ exchanged zeolites

“…In thermal treatment, as temperature increases, cobalt migrates from large cavities to sodalite cages which provide high coordination sites [20][21][22]. Cesium may reach as well sodalite cages.…”

“…Cesium and cobalt act as modifiers in the zeolite structure and, therefore, the compounds obtained by heating an exchanged zeolite with Co 2+ or Cs + are different than those obtained with the monocationic sodium zeolite. For instance Kosanović et al [20] report that zeolite A-Na transforms at 900°C into a mixture of carnegieite and nepheline. At increased temperature (>1000°C) carnegieite completely transforms into nepheline.…”

A novel synthesis of nano-sized mullite from aluminosilicate precursors

“…According to our previous findings [10][11][12][13][14][15], high temperature treatment of zeolites results in, either, (a) transformation of zeolite into X-ray amorphous phase and (b) nucleation and crystal growth of the secondary crystalline aluminosilicate ceramic phase; the particle size and morphology of thus formed phase do not change during the entire process (pseudomorphism). This implies that not only zeolites, but also amorphous gel precursors can be transformed into the secondary crystalline phases, which gives an additional importance to the study of the micro-structural studies of the gel precursors, relevant for the transformation pathways.…”

Microstructural evolution of some MgO–TiO2 and MgO–Al2O3 powder mixtures during high-energy ball milling and post-annealing studied by X-ray diffraction

“…Since the discovery in 1983 that even amorphous alloys can be produced by these techniques [7,8], a new wave of research activity concerned with the possibilities and perspectives of this process has been unleashed. During the past decade we have published the results of our investigations regarding the structural changes in various examined systems induced by ball-mill processing [9][10][11][12][13][14][15][16][17][18][19][20][21][22]. In our and in other investigations [25][26][27][28][29] it has been established, that ball milling can facilitate many solid-state reactions, which normally occur only at elevated temperatures and/or high pressure.…”