Minerals and Material Processing Division, Korea Institute of Geoscience and Mineral Resources, Daejeon, South Korea.
J Environ Sci Health A Tox Hazard Subst Environ Eng. 2009 Dec;44(14):1585-91. doi: 10.1080/10934520903263587.
A novel process was developed using sulfur-oxidizing bacteria to extract metal values like Ni, V and Mo from spent petroleum catalyst. Bacteria were grown in elemental sulfur media for five day and after filtering, the filtrate was used for leaching purpose. Effect of different parameters such as contact time, particle size, pulp density and lixiviant composition were studied to find out the extent of metal leaching during the leaching process. XRD analysis proved the existence of V in oxide form, Ni in sulfide form, Mo both in oxide as well as sulfide forms, and sulfur in elemental state only. In all the cases studied Ni and V showed higher leaching efficiency compared to Mo. The low Mo leaching rate may be either due to formation of impervious sulfur layer or refractoriness of sulfides or both. Leaching kinetics followed dual rate, initial faster followed by slower. Dissolution mechanism was explained on the basis of both surface and pore diffusion rate. The leaching kinetics followed 1st order reaction rate. Finally, multiple linear regression analysis was carried out to compare the observed and calculated leaching percentage values for three metals.
开发了一种新工艺，利用硫氧化细菌从废石油催化剂中提取镍、钒和钼等金属。细菌在单质硫介质中生长五天，过滤后，滤液用于浸出。研究了不同参数（如接触时间、粒度、矿浆浓度和浸出剂组成）的影响，以确定浸出过程中金属的浸出程度。XRD 分析证明 V 以氧化物形式存在，Ni 以硫化物形式存在，Mo 既以氧化物形式存在，也以硫化物形式存在，而 S 则以单质形式存在。在所研究的所有情况下，Ni 和 V 的浸出效率均高于 Mo。Mo 的浸出率较低，可能是由于形成了不渗透的硫层或硫化物的难熔性，或者两者兼而有之。浸出动力学遵循双速率，初始速率较快，随后较慢。溶解机制基于表面和孔扩散速率来解释。浸出动力学遵循一级反应速率。最后，进行了多元线性回归分析，以比较三种金属的观察值和计算值的浸出百分比。
