Characterization of the ash samples before and after thermal processing aiming phosphorus extraction and residues valorization

This paper presents the prospect of phosphorus (P) - rich poultry litter manure ash (PLA) used to recover P through microwave heating methods, aiming for residual slag recycling in constructions. The results show the complex composition of the ashes characterized by X-ray fluorescence (XRF), reflected light optical microscopy, X-ray microanalysis (SEM/EDS) and X-ray diffraction (XRD), which explains the differences between the ash types and the operation temperature in the combustion chamber. At the same time, the results present a novel approach of using microwave heating by reducing energy consumption to extract/enrich P from PLA and forming a by-product/residual slag used as a supplementary cementing material. Samples of fly ash (FA) and bottom ash (BA) were collected from two fluidized bed incinerators (Güres and Beypi in Türkiye) operating at 750 °C and 850 °C within the PHIGO project funded by the 3rd ERA-MIN Program of the European Union Commission.