Mishra Debaraj, Ahn Jong G, Kim Dong J, Roychaudhury G, Ralph David E
Minerals and Material Processing Division, Korea Institute of Geoscience and Mineral Resources, Daejeon, Republic of Korea.
J Hazard Mater. 2009 Aug 15;167(1-3):1231-6. doi: 10.1016/j.jhazmat.2009.01.056. Epub 2009 Jan 23.
Bioleaching studies of spent petroleum catalyst were carried out using sulfur oxidizing, Acidithiobacillus species. Leaching studies were carried out in two-stage, in the first stage bacteria were grown and culture filtrate was used in the second stage for leaching purpose. XRD analysis of spent petroleum catalyst showed oxides of V, Fe and Al and sulfides of Mo and Ni. The leaching kinetics followed dual rate, initial faster followed by slower rate and equilibrium could be achieved within 7 days. The leaching rate of Ni and V were high compared to Mo. The low Mo leaching rate may be either due to formation of impervious sulfur layer or refractoriness of sulfides or both. The leaching kinetics followed 1st order rate. Using leaching kinetics, rate equations for dissolution process for different metal ions were evaluated. The rate determining step observed to be pore diffusion controlled.
利用硫氧化嗜酸氧化硫杆菌对废石油催化剂进行生物浸出研究。浸出研究分两个阶段进行，第一阶段培养细菌，第二阶段使用培养滤液进行浸出。废石油催化剂的XRD分析表明存在V、Fe和Al的氧化物以及Mo和Ni的硫化物。浸出动力学遵循双速率，初始较快随后较慢，7天内可达到平衡。与Mo相比，Ni和V的浸出率较高。Mo浸出率低可能是由于形成了不透水的硫层或硫化物的难熔性或两者兼而有之。浸出动力学遵循一级速率。利用浸出动力学，评估了不同金属离子溶解过程的速率方程。观察到速率决定步骤受孔扩散控制。
