| Abstract [eng] |
In this work the formation conditions of Z-phase and gyrolite in dense samples were examined and also were determined these compounds adsorption properties for copper ions. As the primary materials it was used amorphous SiO2·nH2O and CaCO3. These materials were milled in vibratious disk mill with different grinding modes (SiO2·nH2O was grinded 2,5 min 850 rpm speed and CaCO3 was grinded 30 s 600 rps speed). Before grinding, calcium carbonate was thermally treated at 950 °C temperature. After primary‘s materials preparation, the right amount of them were weighted according to CaO/SiO2 molar ratios which corresponds to 0,55 and 0,66.After that into these mixtures were added 10 % of water of dry solids materials mass amount. These mixtures were homogenized and with press tablet form samples were formed. These dense samples hydrothermally were treated at 200 °C for different durations of synthesis from 4 to 72 h. After synthesis instrumental analysis methods were used to identify compounds on samples surface and also in all samples volume. The results showed that calcium silicate hydrates in the surface of the samples and in all samples volume forms unequally. The bigger crystallite compounds forms on samples surface, while in all samples volume there is less crystal compounds. After 4 h until the synthesis beginning in both type of samples Z-phase already is formed and after 16 h in both type of samples also gyrolite and Z-phase mixture are formed. In the samples also calcite was identified. When C/S ratio was 0,66 and the main synthesis product was gyrolite these samples were used to identify gyrolite adsorption properties for copper ions. Also when C/S ratio was 0,55 and the main synthesis product was Z-phase these samples were used to identify Z-phase adsorption properties for copper ions. So, for adsorption properties research there was chosen hydrothermally treated samples for 4 and for 72 h. These samples were treated with different copper ions concentration solutions (0,25 g/dm3, 1,25 g/dm3, 2,5 g/dm3). It is determined, that after copper ions adsorption in Z-phase structure new compound copper hidroxy nitrate consists. Only after the use of the biggest copper ions concentration of initial solution and small gyrolite fraction for this research in gyrolite structure small amount of copper hydroxyl nitrate was identified. |
