By means of Mössbauer spectroscopy, scanning electron microscopy and thermodynamic analysis methods a detailed study of composition, morphology and properties of ash microspheres obtained at combustion of three coals (Irsha-Borodinsky, Kuznetsky and Ekibastuzsky) has been carried out. The ranges of composition of microspheres suitable for solidification of liquid radioactive waste in the form of iron-phosphate (36-94 wt.% Fe2O3) and aluminosilicate (2-20 wt.% Fe2O3) ceramics have been determined. The possibility of obtaining new materials on the basis of coal dust cenospheres and their application for immobilization of liquid radioactive waste has been shown.
The scheme of separation of cenospheres of energy ashes was developed, laboratory batches of cenospheres of stabilized composition were obtained, their morphological features were studied, macrocomponent and microelement composition was determined. Methods of obtaining porous glass-crystalline material (porous matrices) on their basis have been developed and laboratory batches of porous matrices of various modifications have been obtained. Compositions and conditions for directed solid-phase crystallization of stable mineral-like ceramics like feldspars (strontium anorthite) and feldspathoids (nepheline and cesium-bearing nepheline, pollucite) from porous matrices with sodium, cesium and strontium oxides added in ratios corresponding to real liquid radioactive wastes were determined.
