Abstract: A flotation test on mono-minerals and practical ore of fluorite,calcite and scheelite was conducted.The mechanism of the minerals and TAB-3collector,sodium silicate regulator was studied by infrared spectrum and Zeta potential.The results showed that it was conducive to a flotation separation of scheelite and calcite when the medium pH was adjusted as 8-11by use of Na₂CO₃.It was conducive to a flotation separation of scheelite and fluorite when the medium was pH≥11with NaOH.The role between collector TAB-3and scheelite,fluorite and calcite is chemical adsorption.The collector adsorbed on the surface of fluorite and calcite reduced after adding sodium silicate.Therefore,it is advantageous to the flotation separation of scheelite and fluorite if adding sodium silicate duing their flotation separation,and more advantageous to the flotation separation of scheelite and calcite.