Abstract: Viscosity and flotation of the solutions with different concentrations of magnesium ions were studied.Experimental results confirmed that magnesium chloride(MgCl₂) had an important influence on the viscosity of KCl flotation system.Especially the solution′s viscosity depended on the concentration of magnesium ions.MgCl₂ was bad for the yield improvement of KCl flotation.When the mass fraction of MgCl₂ was less than 20% and the mass fraction of magnesium chloride increased by 1%,the yeild of KCl flotation decreased by about 1%.On the other hand,when the mass fraction of that was higher than 20%,the yield of KCl flotation decreased rapidly,and flotation nearly did not occur until the MgCl₂ chloride concentration reached 26.38% (three-phase invariant point).  

Key words: KCl flotation, magnesium chloride, viscosity, yield