Abstract: Potassium chloride(KCl) with poor quality was obtained because sodium chloride(NaCl) was floated in direct flotation process of KCl.Therefore,it was essentially to study the behavior of NaCl floated with KCl in direct flotation process.Influences of NaCl concentration on the viscosity of solutions,and the particle size of NaCl on its sedimentation rate,recovery ratio,and quality of KCl product were investigated in KCl-NaCl and KCl-NaCl-MgCl₂ solutions at 25 ℃,for decreasing the content of NaCl in KCl product.Results indicated that NaCl with lower particle size could easily adhere to the surface of bubbles or enter into the mineralized bubbles in flotation solutions with higher viscosity.Interference on flotation of KCl caused by NaCl was reduced and the quality of KCl product was efffectively improved when the particle size of NaCl was higher than 125 μm.

Key words: potassium chloride, sodium chloride, viscosity, particle size, flotation