Abstract: Xitieshan leadzinc mine mineral processing workshop has four series production lines,that is Ⅰ,Ⅱ,Ⅲ,Ⅳ,production process is complex,not only reagent used but also pH adjust value are different. To reasonably control pulp pH,via single factor tests,influence of flotation pH on lead concentrate and zinc concentrate grade and recovery about various stages was investigated. Investigated results showed that,leadzinc ore has good floatability in a certain pH range,higher or lower than this range,floatability of leadzinc ore will great influenced. Also,pH value can influence activity of flotation reagents,flotation reagents needs certain pH to stable existence. Xitieshan leadzinc mine mineral processing workshop production lines Ⅰ,Ⅱ,Ⅲ uses low alkaline flotation process,mainly recovery lead,zinc,sulfur. Ⅳ series uses high alkaline flotation process,mainly recovery lead,zinc.

Key words: Pulp pH, Hydrophilic, Floatability, Critical pH