Method for recovering aluminum residue with controlled particle size, and use thereof

A method for recovering an aluminum residue with a controlled particle size, comprising the following steps:

• step 1, crushing and sieving a positive electrode sheet of a waste power battery, then, crushing at −198° C. to −196° C. with addition of liquid nitrogen to obtain a granular material;
• step 2, roasting the granular material, collecting a gaseous binder produced from the roasting with an alkaline solution, cooling, and grinding a residue to obtain a waste positive electrode sheet powder;
• step 3, adding water to the waste positive electrode sheet powder, shaking, settling into layers, and separating the layers to obtain a positive electrode active powder layer, a transition layer, and an aluminum residue particle layer;
• and
• step 4, shaking the aluminum residue particle layer and the transition layer for a second time, settling into layers, and collecting aluminum residue particles and a positive electrode active powder,
• in step 1, the granular material has a particle size of 0.01 μm to 500 μm;
• in step 2, the gaseous binder is polyvinylidene fluoride (PVDF) or polytetrafluoroethylene (PTFE);
• in step 2, a grinder used in the grinding has a treatment capacity of <100 kg/h and a rotational speed of 120 rpm to 180 rpm;
• in steps 3 and 4, during shaking, the waste positive electrode sheet powder are kept immersed in water in a container;
• and the water is deionized water;
• steps 3 and 4 are repeated 1 to 10 times until the aluminum residue particles and the positive electrode active powder in the particles are completely separated and collected.