Nanocomposites and nanomaterials 
Materials capsulating by pyrocarbon in electrothermal fluidized bed
Simeyko K.V.1, Ivachkin Ya.O.1
1 Department of Thermo-chemical Processes and Nanotechnologies,
Gas Institute of the NAS of Ukraine. 
Degtyarivska, 39, Kyiv-03113, Ukraine. 
E-mail: k_simeyko@ukr.net , yapsiva@gmail.com  
Pyrocarbon and pyrographite materials, thanks to their unique physical and chemical properties, have a prospect of application in nuclear power engineering, electrical transport, special metallurgy, machine building, rocket construction, heat exchange equipment and medicine. Expansion of the sphere of industrial use of pyrocarbon and pyrografite materials is limited by their high cost. Reducing energy consumption, increasing the yield of suitable products, reducing the technological cycle of production of these materials eliminates the restrictions on their application. Therefore, research aimed for creating the energy saving technologies for obtaining these materials is actual. In recent years, the Gas Institute of NASU conducted research on the application of pyrocarbon coatings on quartz sand in reactors with an electrothermal fluidized bed. For research, laboratory and pilot facilities have been created. The dependence of the content of pyrocarbon on the temperature is determined. The capsulated material with a wide spectrum of pyrocarbon content (from 2 to 97% by weight) is obtained. Experimentally it was confirmed the principle possibility of silicon carbide obtaining. Pure silicon was obtained from quartz sand covered by pyrocarbon in vacuum furnace. Another area of research is the immobilization of radioactive ash, which was formed as a result of energy objects functioning. It was capsulated by pyrocarbon. As a model of radioactive ash, the authors used the ash remnants of coal-fired power generation, which potentially could represent sources of ionizing radiation. At specially created laboratory plant with an electrothermal fluidized bed it was possible to apply a pyrocarbon coating to this type of ash. An estimation of radiation and protective properties of coatings has been made. It is shown that ionizing β-radiation decreased by approximately 30-35% after coating of ash particles by pyrocarbon, α-activity decreased on 28%.