Zn2+ removal mechanism by bentonite-steel slag composite particles

In order to investigate a high efficient cooperative treatment method of acid mine drainage containing heavy metal ions and develop a new type of multi-function treatment materials,a test was conducted to compare the removal efficiency and experiment phenomenon of self-made bentonite-steel slag composite particles on the treatment of Zn2+ and took the microscopic analysis by SEM and XRD. The results show that the composite particles can release alkalini-ty to neutralize acid;the adsorption and chemical precipitation of Zn2+ occur in the whole reaction process;and the bal-ance removal amount of Zn2+ can reach 8. 01 mg / g;SEM surface microscopic analysis reveals that the composite parti-cles will continue to adsorb and coagulate Zn2+ after the composite particles surface adsorbing Zn2+ and forming precip-itate,namely,there are adsorption-coagulation synergies. XRD microscopic analysis further reveals that the states of Zn2+ in the surface of composite particles are Zn-Si-O mineral phase and Zn12(CO3 )3 SO4( OH)16 polymerization pre-cipitation. The bentonite-steel slag composite particles which can play a role of adsorption-coagulation synergy are ex-cellent multi-function mineral environmental materials to treat acid mine drainage containing heavy metal ions.