This study examined the granulation of fly ash from a thermal power station in Bulgaria to utilize this waste material. The highest yield of granules was achieved using clayish slip as a binder. Adding sodium phosphate as a reinforcing additive increased the granule yield and strength. Sintering the granules increased their density, decreased porosity, and substantially improved their compression strength up to 2.2 MPa, making them suitable for use as a filler in light concretes. The granulation process and additions showed potential for utilizing fly ash waste from thermal power stations.