1, the water concentration magnetic separator extract after the river sand of the sand of the sea water from river or the sea, into the grizzly, sieve to rough stones, into the tub with uniform ore plate, again by adding water to dilute, rinse mortar to evenly to the surface of a cylinder with high magnetic separating area. With high taste of iron sand was adsorbed on the surface of cylinder, high magnetic force and rotation of the cylinder to the bottom of sand washing and after washing water rinse with river sand be transported to the mining area, rushed to the iron ore by water collecting tank, as a high taste of iron sand. Non-magnetic sediment, which is not affected by magnetic effect directly into tailings trough eduction. Thus achieve the goal of extracting iron powder.