Patent ID: 7040969

Claim:
A method for grinding a magnetic member, comprising: a first step of grinding a magnetic member by grinding means having an edge including heat resistant resin and super abrasive grain while supplying grinding fluid to a grinding region; a second step of magnetically separating sludge from the grinding fluid drained from the grinding region by using magnetic separation means; and a third step of introducing the grinding fluid which has undergone the second step into a tank provided therein with a plurality of barrier plates of different sizes capable of turning a flow of the grinding fluid by generally a right angle in a horizontal plane and providing the grinding fluid with a flowing path which changes directions in a horizontal plane at least two times, and separating the sludge from the grinding fluid by magnetic coagulation and subsequent sedimentation of the sludge in the tank, wherein the magnetic separation means includes a magnet roller having a plurality of magnets disposed in longitudinal lines and circumferential rows, polarity of the magnets being alternated in each of the longitudinal lines of the magnets, and in each of the circumferential rows of the magnets.