Abstract:The oxidation of sulfide tailings could lead to acid mine drainage (AMD) and heavy metal pollution problems in the mining area, it was important to prevent the oxidation of sulfide tailing to control the pollution of mining. Previous researches revealed that acidophilic bacteria, represented by Acidthiobacillus ferrooxidans (A.f), played a key role in the process of oxidation of minerals. The aim of this study was to inhibit the biooxidation of sulfide tailing through bactericidal sustained-release capsules. The results proved that sodium dodecyl sulfate (SDS) was an efficient bactericide for A.f. Bactericide sustained release pills were prepared by dripping method. The results of characterization showed that SDS could disperse effectively in the cellulose acetate (CA) skeleton of sustained-release capsules. The loading of SDS was more than 40% and loading SDS could be released continually from capsules into acidic solution, while ρ(SDS) of the solution increased gradually. Bioleaching experiments of pyrite showed that pH, Eh and dissolution rate of heavy metal for the treated samples varied differently with untreated samples. The pH and Eh values of leaching solution kept relatively constant for treated samples comparing to variable for untreated samples, ρ(Zn2+) and total Fe concentrations of leaching solution for treated system were lower than those of untreated system. The study suggested that the sustained-release capsules could prevent the biooxidation of pyrite through inhibiting the growth of A.f, it would be an effective way to control the biooxidation of sulfide tailings in the long term.