表面共价膜抑制黄铁矿光腐蚀动力学试验

Inhibition of pyrite photocorrosion kinetics by surface covalent coating

酸性矿山废水(AMD)主要由尾矿中黄铁矿被腐蚀产酸所造成,太阳光照是不容忽视的重要因素。黄铁矿的光腐蚀过程会导致AMD浸出风险增大。利用三乙烯四胺二硫代氨基甲酸钠(DTC-TETA)在黄铁矿表面形成共价钝化膜,光照条件下,总铁浸出抑制率为99.6%,Fe^(3+)浸出抑制率达到100%。扫描电子显微镜-能量色散X射线光谱(SEM-EDS)、X射线衍射光谱(XRD)和透射电子显微镜(TEM)表征表明,DTCTETA稳定了光化学反应中黄铁矿的结构。DTC-TETA在黄铁矿表面通过含N基团的给电子特性,消耗了AMD浸出模拟液中光致活性氧自由基(ROS,·OH),光照10 h以内·OH生成速率先增大后降低,抑制了金属半导体尾矿的光化学腐蚀反应。

Acid mine drianage(AMD)is mainly caused by pyrite corrosion in the tailings leaching solution to produce acid ions.Sunlight is an important factor that cannot be ignored.The photocorrosion process of pyrite will increase the risk of AMD leaching.Sodium triethylenetetraamine dithiocarbamate(DTC-TETA)forms a covalent passivation coating on the surface of pyrite.Under light illumination condition,the total iron leaching inhibition rate is 99.6%.Fe^(3+)leaching inhibition rate reaches 100%.Scanning electron microscope-energy dispersive X-ray spectroscopy(SEM-EDS),X-ray diffraction spectroscopy(XRD)and Transmission electron microscope(TEM)characterization show that DTC-TETA improves the structural stability of pyrite itself in photochemical reactions.DTC-TETA consumes the photoactived radicals oxygen species(ROS,·OH)in the AMD leaching solution through the electron-donating properties of N-containing groups on the surface of pyrite.The ROS generation rate first increases at short time and then decreases within 10 h.It slows down the photochemical corrosion reaction of metal semiconductor tailings.