Yin and Yang mixed ion exchange (mixed bed) is used for the entry-level pure water further refined. In general, cationic exchange (Yin, also can be set in after electrodialysis or reverse osmosis series, outlet water after can contain silica or less 0.02 PPM, conductive degrees or less 0.02 us/cm. The highly purified water treatment for high pressure boiler, electronic, pharmaceutical, papermaking, chemical and petroleum industries.