Ceramics and glass-ceramics are thermodynamically stable systems, which serve as an alternative for industrial glasses by a number of physico-chemical characteristics. Solid matrixes on their basis are prospective for fixation of radionuclides in the processing of liquid radioactive wastes for solidification. Also, ceramics can be used as supports for radionuclides in the radioisotope production (radiopharmacy, ionizing irradiation sources and etc.). Matrix’ quality should satisfy strict requirements of radiation security and can be achieved by the means of cutting edge technologies like Spark Plasma Sintering (SPS) one. The work studies applicability of SPS for fabrication of highly dense ceramic and glass-ceramic matrixes containing radionuclides, which are based on zeolites of diverse origin, namely natural, with mixed phase composition (clinoptilolite, mordenite, heulandite), and commercial types (NaA, NaX, NaY) as well as synthetic zeolite samples with variable ratio SiO2:Al2O3. Fundamental contribution includes new information about mechanisms of zeolite powder consolidation under non-equilibrium spark plasma treatment. For the first time, physico-chemical peculiarities of phase transformations and structural changes in SPS processed zeolites has been studied. SPS treatment has been shown to demolish mineral crystal phases of natural and commercial zeolites into amorphous phases, while synthetic zeolites are transformed into pollucite (CsAlSi2O6) by spark plasma depending on affinity to immobilized Cs ions. Densification kinetics of studied dispersed zeolites has been established for different sintering regimes and for various amounts of retained Cs ions. Structural characterization of zeolites has been studied by low temperature sorption of nitrogen, argon and krypton with the influence of retained Cs ions on the structure of consolidated alumosilicated being addressed. Hydrolytic stability and fixation properties of the matrixes have been studied with respect to diffusional migration of indicated radionuclide imitator into solution. Optimal SPS regimes, which were unknown earlier, has been described for consolidation of disperse zeolites to obtain high-quality ceramic and glass-ceramic matrixes of high density (~99.8% from theoretical), compressive strength (~732 MPa), containing to 24.3% of Cs ions and with low rates of their desalination (<10-6–10-7 g cm-2·day-1). Results of research are of great practical interest for nuclear industry, where SPS technology can be implemented to tackle various technological challenges.

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