Patent ID: 7999205

Claim:
A method of separating foreign particles, for carrying out separation of intended material particles and unintended material particles from each other from mixed powder including the intended material particles and the unintended material particles that are mixed therein and have different properties from each other, by one of electrostatic separation and magnetic separation, the method of separating foreign particles comprising the steps of: classifying the mixed powder by using a centrifugal classifier or an inertia classifier to remove the fine powder having a spherical equivalent diameter of 10 μm or smaller so that a content of fine powder, which has a spherical equivalent diameter of 10 μm or smaller, contained in the mixed powder is 15 mass % or less; and imparting one of an electric charge and magnetism to the mixed powder, from which the fine powder has been removed, to separate the intended material particles and the unintended material particles from each other.