<p> It is claimed in the literature that there is a close connection between sodalite, nosean, and hauyne in their chemical and crystalle-graphic properties and that they may well be isomorphous (Winchell and Winchell, 1951; Barth, 1933). Close relation between the cancrinites and the sodalite minerals of sodalite itself and nosean and hauyne have been implied (Larsen and Steiger, 1916; 1931, 1944). </p> <p> Mixtures of sodalite, nosean and hauyne were made up and heated at temperatures of 100 degrees Celsius to 750 degrees Celsius at pressures ranging from 10,000 to 30,000 psi. Both nosean and hauyne exhibited polymorphism with a cancrinite type of structure below and a nosean or hauyne structure above approximately 475 degrees celsius. Synthetics products of sodalite composition did not show this structural change. </p> <p> The structure of nosean along the cube diagonal was deduced parallel to the 111 plane (along the triagonal axis) which was compared with the cancrinite strcutre as given by both Pauling (1930B) and Kozn and Takane (1933). A possible mechanism for the polymorphism was deduced from projection drawings and scale models. </p> <p> There was no tendency for the synthetic products of these three minerals to dissociate at any of the temperatures and pressures used in this study. Preformed synthetic or naturally occurring sodalite, on the other hand, did have a tendency to dissociate to nepheline although an actual dissociation curve probably does not exist. More likely the water content is the more dominant factor than temperature or pressure. </p> <p> There appears to be complete solid solution between nosean and hauyne but only partial solid solution between sodalite and nosean, and sodalite and hauyne. </p> <p> The substitution of strontium and barium for sodium and calcium is investigated and discussed. </p> / Thesis / Master of Science (MSc)

This thesis is focused on the possibilities of the utilization of the fludized fly ash in ceramic technology, especially in the field of brick manufacturing and ceramic tiles. There were used fly ashes from thermal power plants in Hodonín, Ledvice and Tisová. Fluidized fly ash can be used for manufacturing of building materials. There hasn’t been done extensive research in this area. One of the problem is sulphur dioxide leakage during burning. The work describes the behaviour of fluidized ash during firing. The attention is focused on air pollution of sulphur dioxide. The production of SO2 is controlled so that the aim of the work is to find a way how to avoid leaking. It was proved that addition of sodium ions causes the formation of minerals hauyne and nosean during firing. Also is described the behaviour of the fly ash-soil mixtures. The anhydrite decomposition temperature is lower than in pure fly ash. In the end is fluidized ash applied for the production of dry pressed ceramic tiles. This ash can be used in ceramic technology. However, despite the interesting results there are number of problems that need to be solved.