硫化物矿山尾矿缓释抑菌剂滴丸的制备及性能测试

为阻止或减缓嗜酸性硫氧化菌对硫化矿物的氧化,研究了十二烷基磺酸钠(SDS)对广东韶关大宝山多金属尾矿区分离出的氧化亚铁硫杆菌的杀菌效果.为提高抑菌剂的有效利用率,采用滴制法将其制备成具有缓释功能的抑菌剂滴丸,并分析了抑菌剂滴丸的表面特征、元素组成及缓释性能.结果发现:滴制法可以把SDS均匀地分散在以醋酸纤维素为骨架的缓释滴丸内部;滴丸的载药率可以达到40%以上;实验周期内杀菌成分可在酸性溶液中持续缓慢溶出,溶液中ρ(SDS)逐渐升高.氧化亚铁硫杆菌摇瓶浸矿结果显示:使用抑菌剂缓释滴丸后,实验周期内溶液的pH值、Eh变化幅度较小,而且Zn2+、总Fe的溶出率分别比未加滴丸的处理低61.37%、84.44%,缓释杀菌作用显著.

Preparation and performance testing of bactericide sustained-release capsules

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.