Recycling Mn compounds from spent alkaline batteries (SABs) not only follows the ongoing trend of circular economy but also conserves nature without disposal of hazardous battery wastes. Both pyrometallurgical and hydrometallurgical techniques were included to aim for a low-cost, environmental-contaminant-minimized, and mass-production process. The SAB-electrode powder mainly consisted of Mn(III) compounds by X-ray diffraction (XRD), together with ca. 6 wt % carbon by X-ray fluorescence (XRF). Heat treatment under N