The　physical,　chemical,　mineralogical　and　toxicity　attributes　of　two　fluidized　bed　combustion　(FBC)　coal　fly　ashes　were　evaluated,　and　were　compared　against　that　of　a　conventional　coal　fly　ash.　The　potential　use　of　the　FBC　ash　in　alkali-activated　binders　was　also　evaluated.　Alkali-activated　mortars　were　prepared　and　tested　for　compressive　strength　at　different　ages.　The　alkali-activated　binders　were　also　evaluated　using　SEM,　TGA　and　FTIR　methods.　This　investigation　accounted　for:　(i)　the　differences　in　the　combustion　temperatures　of　FBC　versus　conventional　methods　of　coal　combustion;　(ii)　capture　of　sulfur　from　combustion　emissions　in　the　FBC　method,　and　its　incorporation　into　fly　ash　as　crystalline　solids;　and　(iii)　the　type　and　particle　size　of　the　sorbent　used　in　the　FBC　process　for　capture　of　sulfur　from　combustion　emissions.　FBC　ashes　were　found　to　differ　from　the　conventional　coal　fly　ash　in　terms　of　chemical　composition,　crystalline　phases　and　carbon　content.　The　higher　crystallinity　and　carbon　content　and　the　larger　particle　size　of　FBC　ashes　were　noted　to　challenge　their　potential　use　in　alkali-activated　binders.　Suggestions　are　made　based　on　the　experimental　results　towards　effective　use　of　FBC　ashes　in　alkali-activated　binders.Abbreviations:　FBC:　Fluidized　Bed　Combustion;　SEM:　Scanning　Electron　Microscope;　TGA:　Thermogravimetric　Analysis;　DTA:　Differential　Thermal　Analysis;　XRF:　X-Ray　Fluorescence;　XRD:　X-Ray　Diffraction;　LOI:　Loss-On-Ignition;　TDS:　Total　Dissolved　Solids;　EPA:　Environmental　Protection　AgencyI;　CP-OES:　inductively　couple　plasma　spectroscopy;　DI:　Deionized;　CFB:　Circulating　Fluidized　Bed;　ASTM:　American　Society　for　Testing　and　Materials.　©　2022　Taylor　&　Francis　Group,　LLC.