The invention relates to a method and a device for permanent-
magnet arc-shaped groove inner surface axial sorting. The method comprises the following steps: the sorted materials flowing through the
field intensity of the inner surface of a rotating separating drum (2) and the sorted materials in a gradient area are absorbed by using the energy on the inner surface of a permanent
magnet arc-shaped groove (1); the materials with lower specific susceptibility flow out from a low-magnetic material outlet (9) through a sorted material channel (13), and the materials with higher specific susceptibility are absorbed on the rotating separating drum (2), directly fall to a high-magnetic
silo (7) by means of the own gravity, flow through a high-magnetic material outlet (8) and then are collected, therefore, the purpose of sorting the materials with different specific susceptibility is achieved. The invention has the advantages that the yield and the
recovery ratio are greatly improved; the sorting range can be extended, and the sorting loss of the valuable substances is reduced; no sorting missing exists, and the sorting effect is good; the overall inclination angle theta is adjustable, the
field intensity and the gradient can be changed, and the region angle of the
field intensity and the gradient is 10-350 degrees; the permanent-
magnet arc-shaped groove adopts the open
loop design, therefore, the permanent magnet material is saved; and the separating drum is not required to be eccentrically arranged and can be easily manufactured and installed.