<p>Sintered ore, a by-product of ironmaking, is rich in calcium ferrate phases (Ca_xFe_yO_z) and represents a promising, low-cost material for flue gas purification. This study systematically investigated its potential for NO adsorption and catalytic reduction, aiming to develop a novel, waste-based catalyst for sintering flue gas treatment. To overcome the high cost and poor stability of conventional selective catalytic reduction (SCR) systems, we propose an integrated process using regenerated sintered ore as a catalytic bed material in a circulating fluidized bed boiler. The adsorption and reduction of NO were efficiently achieved at characteristic sintering flue gas temperatures (700–800&#xa0;°C). The mechanism was elucidated through gravimetric sampling, scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), Brunauer–Emmett–Teller (BET) surface area analysis, and X-ray diffraction (XRD). A Langmuir model was developed to quantify the adsorption equilibrium and reduction rate constants. This work, through combined experimental analysis and Langmuir modeling, demonstrates the dual functionality (adsorbent and catalyst) of calcium ferrate derived from sintered ore and provides insights for a feasible ‘waste-to-resource’ strategy for sustainable metallurgy.</p> Graphical Abstract <p></p>