Abstract: A method according to an embodiment is for recovering a valuable metal from a waste electrode material of a lithium secondary battery by using lithium carbonate. An anode-cathode mixed electrode material that has been separated by draining, crushing, screening, and sorting a waste lithium secondary battery is preprocessed. A precipitation operation performed by adding lithium carbonate (Li2CO3) to a metal melt acquired by performing sulfuric acid dissolution using sulfuric acid. A valuable metal such as nickel, cobalt, manganese, aluminum, and copper is recovered as a residue in the form of a carbonate composite, and a lithium sulfate (Li2SO4) aqueous solution including lithium is recovered as a filtrate.

Abstract: An air cleaner adapted to filter out various types of substances through a filter assembly, as well as automatically remove the filtered substances, and a method for controlling the operation of such an air cleaner, are provided. The air cleaner may include a rotation brush unit installed on an inner wall surface of a front panel, facing a front surface of a mesh-type filter body and adapted to rotate while maintaining contact with the front surface of the filter body. When a suction operation is terminated, the rotation brush unit may to remove dust accumulated on the surface of the mesh-type filter body.

Abstract: Disclosed is a new type of air cleaner adapted to primarily filter out various types of alien substances (e.g. dust) through a filter assembly, as well as automatically remove the alien substances that have been filtered out, and a method for controlling the operation of the air cleaner. The air cleaner includes a rotation brush unit installed on the inner wall surface of the front panel to face the front surface of the mesh-type filter body and adapted to rotate while maintaining contact with the front surface of the mesh-type filter body. When the air-drawing unit stops operation, the rotation brush unit is operated to remove dust accumulated on the surface of the mesh-type filter body of the filter assembly, which is installed near the air inlet.