The permanent-magnetic roller separators are used in mines and coal separating factories to separate the wet fine highly magnetic substances or remove the highly magnetic substances from the non-magnetic materials. The separators have three types of tanks: half countercurrent tank (CTB), direct flow tank (CTS) and countercurrent tank (CTN), which are used according to different granular and technological requirements. The features of our products are: optimized computer design, rational magnetic circuit, strong magnetic coercive force and high-remanence permanent magnet which can keep the magnet performance in a long period and safe-guard the long-term interest of the customers. The whole structure is reliable.