Keywords
Abstract
The annual accumulation of Coal Ash and Slag Waste (CASW) at TPP ash dumps poses a critical environmental challenge, particularly in Kazakhstan due to the high ash content (approximately 40%) of Ekibastuz coal. This yields millions of tonnes of waste on vast technogenic deposits. The problem is twofold: fly ash contaminates soil and groundwater with heavy metals, and water from hydro-ash removal systems (HARS) is a highly mineralized effluent requiring costly disposal. The low utilization rate necessitates the complex integration of solid and liquid waste components into industrial circulation as a strategic priority. This timely solution addresses the dual environmental problem, simultaneously reducing waste volumes and significantly decreasing the consumption of natural resources (cement and fresh water) in the construction industry. This article specifically investigates the feasibility of the integrated use of CASW derived from Ekibastuz coal: utilizing fly ash as a mineral admixture and employing water from HARS as the mixing water in the production of lightweight cellular concrete, namely polystyrene-foam concrete. The research is dedicated to studying the combined effect of these two components on the processes of structure formation and the resultant key physic and mechanical properties of the cement stone. To ensure the safety and characterize the raw materials, including the ash from the Ekibastuz Basin, the study utilized X-ray fluorescence analysis (XRF), X-ray diffraction analysis (XRD), and structural morphology assessment using a scanning electron microscope (SEM). The article presents the detailed findings on the physic and mechanical properties of the obtained composites, confirming their potential for safe and effective industrial application.