Selective milling-flotation method for cassiterite multi-metal sulfide ore

The invention discloses a selective milling-floatation method for cassiterite multi-metal sulfide ore. In the method, cassiterite multi-metal sulfide ore is selectively milled, so that the surface hydrophilic/hydrophobic properties of cassiterite and sulfide minerals such as iron pyrite, pyrrhotite, zinc blende, jamesonite and the like in ore are changed, the surface of cassiterite does not react with a flotation collector but reacts with hydroxamic acid polyacrylamide, and selective flocculation is performed on the surfaces of cassiterite minerals; and surfaces of minerals such as iron pyrite, pyrrhotite, zinc blende, jamesonite and the like do not adsorb hydrophilic substances, and a fresh surface which is obtained by milling ore and dissociating reacts with a flotation collector which is added into an ore mill, so that floatability is realized for the surface hydrophilic property, the problems of low cassiterite floatation efficiency, high tin loss rate and severe environmental pollution caused by excessiv