中国有色金属学报（英文版）
中國有色金屬學報（英文版）
중국유색금속학보（영문판）
TRANSACTIONS OF NONFERROUS METALS SOCIETY OF CHINA
2012年
3期
731-739
,共9页
镍黄铁矿%嗜酸氧化亚铁硫杆菌%生物浸取%改性微电极
鎳黃鐵礦%嗜痠氧化亞鐵硫桿菌%生物浸取%改性微電極
얼황철광%기산양화아철류간균%생물침취%개성미전겁
pentlandite%Acidthiobacillus ferrooxidans%bioleaching%powder modified microelectrode
应用表面粘附和没有粘附Acidithiobacillus ferrooxidans的镍黄铁矿粉末微电极进行电化学测试,以说明镍黄铁矿氧化分解的机理.循环伏安CV结果显示,在-0.2 V的低电位区域,在镍、铁离子析出时镍黄铁矿转变为中间相Fe4.5-yNi4.5-xS8-z;当电位在-0.2 V到0.2 V区间时,有不稳定的紫硫镍矿Fe3Ni3S4和FeNi2S4形成并在表面伴有元素硫的产生；当电位增加到0.2 V以上时,不稳定相将全部分解:在高电位0.7 V时,析出的亚铁离子被氧化为高铁离子.嗜酸氧化亚铁硫杆菌Acidithiobacillus ferrooxidans的存在使峰电位增高,反应起始电位负移,并对表面形成的元素硫有氧化去除作用.这一过程可通过-0.75到-0.5 V电位区间发生的的还原反应证实.生物浸出和电化学实验结果均表明当pH＜2时溶液酸度的增加对氧化过程有轻度的阻碍作用.
應用錶麵粘附和沒有粘附Acidithiobacillus ferrooxidans的鎳黃鐵礦粉末微電極進行電化學測試,以說明鎳黃鐵礦氧化分解的機理.循環伏安CV結果顯示,在-0.2 V的低電位區域,在鎳、鐵離子析齣時鎳黃鐵礦轉變為中間相Fe4.5-yNi4.5-xS8-z;噹電位在-0.2 V到0.2 V區間時,有不穩定的紫硫鎳礦Fe3Ni3S4和FeNi2S4形成併在錶麵伴有元素硫的產生；噹電位增加到0.2 V以上時,不穩定相將全部分解:在高電位0.7 V時,析齣的亞鐵離子被氧化為高鐵離子.嗜痠氧化亞鐵硫桿菌Acidithiobacillus ferrooxidans的存在使峰電位增高,反應起始電位負移,併對錶麵形成的元素硫有氧化去除作用.這一過程可通過-0.75到-0.5 V電位區間髮生的的還原反應證實.生物浸齣和電化學實驗結果均錶明噹pH＜2時溶液痠度的增加對氧化過程有輕度的阻礙作用.
응용표면점부화몰유점부Acidithiobacillus ferrooxidans적얼황철광분말미전겁진행전화학측시,이설명얼황철광양화분해적궤리.순배복안CV결과현시,재-0.2 V적저전위구역,재얼、철리자석출시얼황철광전변위중간상Fe4.5-yNi4.5-xS8-z;당전위재-0.2 V도0.2 V구간시,유불은정적자류얼광Fe3Ni3S4화FeNi2S4형성병재표면반유원소류적산생；당전위증가도0.2 V이상시,불은정상장전부분해:재고전위0.7 V시,석출적아철리자피양화위고철리자.기산양화아철류간균Acidithiobacillus ferrooxidans적존재사봉전위증고,반응기시전위부이,병대표면형성적원소류유양화거제작용.저일과정가통과-0.75도-0.5 V전위구간발생적적환원반응증실.생물침출화전화학실험결과균표명당pH＜2시용액산도적증가대양화과정유경도적조애작용.
Electrochemical measurements were carried out to elucidate decomposition mechanism of pentlandite using modified powder microelectrode with Acidithiobacillus ferrooxidans attached or without on the mineral powder surface.Cyclic voltammetry (CV) results show that at a low potential of about -0.2 V (vs SCE),the pentlandite was transformed to an intermediated phase like Fe4.5-yNi4.5-xSR-z when Fe and Ni ions were evacuated from mineral lattice; when the potential was changed from -0.2 V to 0.2 V,the unstable violarite (Fe3Ni3S4) and FeNi2S4 were formed which was accompanied by element sulfur formed on the mineral surface;when the potential increased over 0.2 V,the unstable intermediated phase decomposed entirely; at a higher potential of 0.7 V,the evacuated ferrous ion was oxidized to ferric ion.The presence of Acidithiobacillus ferrooxidans made the oxidation peak current increase with initial peak potential negatively moving,and the bacteria also contributed to the sulfur removing from mineral surface,which was demonstrated by the reduction characteristic at potential ranging from -0.75 to -0.5 V.Leaching experiments and electrochemical results show that the solution acidity increasing when pH＜2 may impede the oxidation process slightly.
