Abstract: Effects of different degree of acidification water glass on the floatability of barite and dolomite as well as its possible principle of action were studied by means of single mineral flotation, solution chemical calculation, Zeta potential test and infrared spectroscopy. The flotation results indicate that: dolomite can be well suppressed and barite floatability is less affected by acidification degree of 1 water glass (TS11). Mechanism study results show that: under the sodium dodecyl sulfonate flotation system, TS11 hydrolysis generation a strong hydrophilic silicate particles Si(OH)₄ with the dolomite surface Ca²⁺ occurs strong chemical adsorption, and squeeze C₁₂H₂₅OS \mathrmO_3^- which adsorbed on the surface of dolomite through competitive adsorption, resulting in a sharp reduction in the floatability of dolomite, but it is difficult to adsorb on the surface of barite, so TS11 has a good selective inhibition.