| Under hygrothermal climate, a series of physicochemical changes take place on huebnerite-scheelite deposit,containing polymetallic sulphi-des and slich a deposit forms a secondary tungsten deposit.It is studied that most of tungsten in ore occurs in secondary psilomelane in the form of adsor-bed ions. Though W grade can be increased, it is difficult to better recover tungsten with mechanical beneficiation methods. |