... . The sand and stone flow into washing launder from feeding launder, rolls with the impellor, and grinds ... will take away waste and some low-weight wastes from washing launder. Through the above process, the ... the washing launder. On one hand, water is removed from the sand and stone; on the other hand, ... the sand and stone goes to the out launder from the rotary impellor to finish the washing task. ...