Processing of ash and slag waste

Abstract

This article is dedicated to the identification of perspective areas for the disposal of ash and slag waste from thermal power plants, namely waste generated at the TPP-1 in Pavlodar. The composition of ash and slag waste was considered by methods of X-ray fluorescence and X-ray phase analysis in order to identify the most suitable area for their further use. Based on the data obtained, it was proposed to use waste for the extraction of precious metals, such as aluminum and iron, by alkaline leaching. The paper presents the results of selection of the most optimal conditions (temperature, alkali concentration, duration of the process) leaching of metals. It was found that the best conditions for the extraction of iron is the treatment of ash and slag waste in an alkaline environment of caustic soda with a concentration of 200 g / l at a temperature of 80 °C for 3-4 hours. To increase the degree of aluminum extraction, it is necessary to apply repeated treatment with an alkali solution, consisting in sequential treatment of ash and slag waste with fresh alkali solutions in 3 stages for one hour.