Martin S.,Institute of Montaneous science and Environmental Protection |
Maria P.,Institute of Geotechnics
Acta Montanistica Slovaca | Year: 2010
The utilization of fly ashes in Slovakia is lower than in other countries and dumping of fly ashes prevails. The dumping changes chemical and phase composition of fly ashes and so it decreases possibilities for their utilization. Fly ashes are mainly used in building industry, where the content of loss on ignition (LOI) is limited due to standards. Black coal fly ashes produced in Slovakia have a high content of loss on ignition - more than 20% - so they straight utilization in building industry is not possible. The current possibility for their utilization is in geopolymer synthesis. Products with 28-day compression strength of 35.7 MPa and 180-day compression strength of 55.0 MPa were obtained by alkali activation of fly ashes with 23.25% LOI with 8 wt% Na 2O and their next hardening in temperature of 80 °C during 6 hours. Products have a great frost-resistance and aggressive environments resistance (NaCl a H 2SO 4 solutions).
Horniakova E.,TU of Kosice |
Marcinova L.,Institute of montaneous science and environmental protection |
Bugel M.,Institute of montaneous science and environmental protection
Acta Montanistica Slovaca | Year: 2012
The research deals with processes occurring in the activation tank during the snow-melt inflow of chemical component of road salt. Chemical composition of the suspension in the activation tank is changing following the metabolism of organisms and chemical composition of the influent wastewater. Sludge and wastewater in nitrification tail of the activation tank has higher conductivity, higher contents of chloride, higher sludge index and other characteristics are changing during snow - melt. The amount of the inflow road salt is a determining factor of lyses of microorganism cells.
Treatment processes for utilization of high carbon fly ashes from combustion of black coal in thermal power plants [Technologie przeróbcze uszlachetniania, zawieraja̧cych czçści palne, popiolłów lotnych z wȩgli kamiennych spalanych w elektrocieplłowniach]
Michalikova F.,Institute of Montaneous science and Environmental Protection |
Skvarla J.,Institute of Montaneous science and Environmental Protection |
Sisol M.,Institute of Montaneous science and Environmental Protection |
Krinicka I.,Institute of Montaneous science and Environmental Protection |
Kolesarova M.,Institute of Montaneous science and Environmental Protection
Inzynieria Mineralna | Year: 2010
The article presents potential treatment technologies for black coal ash from melting boilers and opportunities for utilization of obtained products - unburned coal residues, Fe-concentrates and fly ash cleaned from unburned coal particles utilizable mostly in building industry. Single useful components were separated by the process of flotation and wet magnetic low-intensity separation. Obtained products are industrially utilizable. The results of laboratory tests are the basis for evaluation the possibilities for utilization this type of fly ashes as a precursors for geopolymer production and for utilization in building industry.