Příprava syntetických ekvivalentů zeolitů na bázi energetických odpadů a jejich kompozitních směsí s vhodnými aditivy pro korekci prvkového složení.

Abstract

SEP are formed when black or brown coal is burned in coal fired thermal power plants. These SEP products are mainly due to technologies that are designed to protect the environment and human health. The amount of these SEP increases every year, and therefore there is an effort to use the most of them. Fly ash is one of these SEP and forms the majority of the SEP generated. These SEP are used for other purposes according to their properties. Fly ash has found a wide range of applications from construction, metallurgy, chemical production, reclamation,… One of the potential uses of fly ash is hydrothermal synthesis. In this work I worked with fly ash coming from power plant Dětmarovice a.s. These fly ashes came from electrostatic precipitators and from mechanical grade. These two types of fly ash were label as fly ash No. 1 and fly ash No. 2. Fly ashes were subjected to XRD, XRF, SEM input analysis, particle size measurement, specific surface area and LOI. These fly ashes were then used for the convection hydrothermal method. Different concentrations and amounts of NaOH, LiCl and aqueous glass were used for the experiments. Furthermore, the process temperature was varied from 90-120 °C, and also length, which was in the range of 6-48 h. Most of the experiments were supplemented with a crystallization phase that was run for 16 h at 50 °C. The product of the convection hydrothermal synthesis process was subjected to XRD, SEM and specific surface area analyzes. With an XRD was measured the zeolite phase content in product. XRD results were confirmed by SEM analysis. The specific surface area was measured for selected samples to determine whether the SBET, St, as well as the volume of the micro pores. In the experiments in this work, the content of zeolite phase was found in almost all hydrothermal synthesis products. At this work was obtain zeolite phases were Faujasite Na, Faujasite-Ca, Chabazite, Phillipsite and Sodalite. The content of these zeolite phases ranged from 2.09 % to 43.79 %. Measuring specific surface area shows us that the product of convection hydrothermal method increases SBET, St, as well as the volume of micro pores relative to the input fly ash values. The results of these experiments show us that a convection hydrothermal method can be a suitable method for converting fly ash as a SEP to a zeolite phase which can has better properties than input fly ash.