Development of methods for preparing fly ash for separation by activation

Abstract

Purpose. Isolation of the aluminosilicate fraction from fly ash, study of physical and mechanical properties of binders obtained from TPP wastes. Methods. Ash, carbon concentrate (underburn), ash concentrate and products of their treatment with reagents were tested by optical methods. The morphology of the particles of the subjects of inquiry was studied with the scanning electron microscope REM-100. The composition of the ash phases was investigated using the X-ray diffractometer DRON-2. Findings. The technology of sorbents based on coal combustion products through a variety of methods was researched. It is shown that these sorbents are distinctive because their structure has non-localized pi-electrons of the graphite-like networks of crystallites of carbon. This circumstance determines not only the uniqueness of electro-physical properties of coal but also adsorption, redox, chemisorption processes on the border of coalslurry. The listed circumstances allow you to use the original methods of chemical and mechanochemical modification of the surface chemical and coal, due to introducing desired donor and acceptor atoms in carbon frame, which increases the absorption capacity and selectivity carbon sorbents. Practical implications. The article presents the results of receipt of binders based on TPP ash. It has been shown that a component of the fly ash is aluminosilicate spheres that can be used in the production of lightweight concrete. It is proved that the result of mechanochemical activation mixture consisting of alumino-silicates, resulting lightweight concrete has high strength 7-8 MPa, which allows, while maintaining the technical characteristics save from 20 to 30 % of binder. Concrete obtained based on aluminosilicate spheres separated from fly ash may be used to prepare the outer wall construction, small building blocks, as well as monolithic housing. In comparison with known compositions keramsit compositions comprising TPP waste.