The machine consist of the motor reducer, tank, magnetic roller, rubber roller, etc.motor reducer drive the magnetic roller along circular direction, after cooling fluid that contain powdered magnetic impurities flow into the tank, impurities are adsorbed to the surface of the magnetic roller,the adsorbed impurities will be roller compaction by the rubber roller when the magnetic roller rotate,so the liquid that is mixed with impurity is discharged,the impurity is dry. finally the scraper blade scrape the impurities from magnetic roller and fall into the collection box.