Abstract: Graphitized spent carbon cathode (SCC) is a hazardous solid waste generated in the aluminum electrolysis process. In this study, a flotation–acid leaching process is proposed for the purification of graphitized SCC, and the use of the purified SCC as an anode material for lithium-ion batteries is explored. The flotation and acid leaching processes were separately optimized through one-way experiments. The maximum SCC carbon content (93wt%) was achieved at a 90% proportion of −200-mesh flotation particle size, a slurry concentration of 10wt%, a rotation speed of 1600 r/min, and an inflatable capacity of 0.2 m³/h (referred to as FSCC). In the subsequent acid leaching process, the SCC carbon content reached 99.58wt% at a leaching concentration of 5 mol/L, a leaching time of 100 min, a leaching temperature of 85°C, and an HCl/FSCC volume ratio of 5:1. The purified graphitized SCC (referred to as FSCC-CL) was utilized as an anode material, and it exhibited an initial capacity of 348.2 mAh/g at 0.1 C and a reversible capacity of 347.8 mAh/g after 100 cycles. Moreover, compared with commercial graphite, FSCC-CL exhibited better reversibility and cycle stability. Thus, purified SCC is an important candidate for anode material, and the flotation–acid leaching purification method is suitable for the resourceful recycling of SCC.