ADSORBING COLLOID FLOTATION OF PB(II) - FEASIBILITY OF UTILIZING STREAMING CURRENT DETECTOR

A feasibility study was conducted to assess the application of a strea ming current detector (SCD) in the flotation of dissolved heavy metals . The adsorbing colloid flotation of Pb(II) with iron oxide and sodium dodecylsulfate was investigated. Both zeta potential and streaming cu rrent (SC) readings of each colloidal system were measured. For colloi ds of goethite or of amorphous iron oxide, the results show SC changed with pH values and can be well correlated to the zeta potential. The removal of Pb(II) increased with increasing pH. Judging from the exper imental results, it is proposed that when pH is at 3.0 or lower, Pb(II ) is mainly removed by foam fractionation. When pH values are between 4.0 and 7.0, Pb(II) removal can be attributed to both foam fractionati on and adsorbing colloid flotation. When pH values are higher than 7.0 , Pb(II) is mainly removed by precipitate flotation in the form of Pb( OH)(2)(s) or Pb-Fe coprecipitate. Advantages and limits of utilizing S CD in flotation processes are discussed. Preliminary results show it i s feasible for SCD to be utilized in the flotation of Pb(II).