(1. 北京科技大學(xué) 土木與資源工程學(xué)院，北京 100083;
2. 中國(guó)科學(xué)院 過程工程研究所 生化工程重點(diǎn)實(shí)驗(yàn)室，北京 100190)
摘 要: 為利用多金屬結(jié)核與低品位硫化鎳礦，提出嗜酸氧化亞鐵硫桿菌(Acidithiobacillus ferrooxidans，At. f 菌)共浸出鎳、鈷、銅、錳工藝，考察有無Fe(Ⅲ)和At. f菌體系中S/Mn礦石質(zhì)量比、礦漿濃度、攪拌速度、溫度、接菌量和pH值對(duì)主金屬元素浸出的影響，通過循環(huán)伏安、電化學(xué)極化、計(jì)時(shí)電流、XRD和SEM等分析手段揭示多金屬共浸出過程中At. f菌的增速作用機(jī)理。結(jié)果表明：At. f菌可提高主金屬元素浸出速度和回收率；At. f菌存在時(shí)，多金屬結(jié)核陰極-低品位鎳礦陽極電極間電位差增大，F(xiàn)e3+/Fe2+和S0/S2-氧化還原加快，從而加速腐蝕反應(yīng)。At. f菌促進(jìn)多金屬結(jié)核溶解過程電子轉(zhuǎn)移和物質(zhì)交換，引起低品位硫化鎳礦氧化還原電位負(fù)移并釋放吸附礦石表面S0電子。有菌浸取時(shí)的鎳、錳、銅和鈷浸出率分別達(dá)95.34%、97.34%、92.24%和97.75%，比無菌浸取時(shí)的分別提高8.78%、4.78%、10.34%和5.46%。
關(guān)鍵字: 生物共浸出；電位差；電化學(xué)極化；電子轉(zhuǎn)移；氧化還原
（1. School of Civil and Resource Engineering, University of Science and Technology, Beijing 100083, China;
2. Key State Laboratory of Biochemical Engineering, Institute of Process Engineering, Chinese Academy of Sciences, Beijing 100190, China）
Abstract:For the extraction of Ni, Cu, Co, and Mn from polymetallic nodule and low-grade nickel sulfide ore, a simultaneous bioleaching was investigated by using Acidithiobacillus ferrooxidans(At. f). The extraction regularity was measured by effect of mass ratio of S/Mn, pulp density, agitation speed, temperature, inoculation amount of bacteria and pH on the leaching of major metal elements. The feature and mechanism of the acceleration of At. f was determined by cyclic voltammetry, electrochemical polarization-curve, chronoamperometry, XRD and SEM analysis. The results show that the leaching rate and recovery of major metal elements increase with admixing At. f. Acidithiobacillus ferrooxidans prospers the corrosion, by accelerating the mutual transformation of Fe3+/Fe2+ and S0/S2- electron couples and by increasing the potential difference between the anode of low-grade nickel sulfide ore and the cathode of polymetallic nodule. Acidithiobacillus ferrooxidans can also improve the electron transfer and substance exchange in the dissolution of polymetallic nodules, cause a negative movement of the corrosion potential of nickel ore, and increase in the electron release of the adherent S0. With the presence of At. f, the extraction ratios of Ni, Mn, Cu and Co during bioleaching are 95.34%, 97.34%, 92.24% and 97.75%, respectively, and more than those during inorganic leaching by 8.78%, 4.78%, 10.34% and 5.46%.
Key words: simultaneous bioleaching; potential difference; electrochemical polarization-curve; electron transfer; oxidation-reduction
