Medina-Díaz Hassay Lizeth, Acosta Irene, Muñoz Martín, López Bellido Francisco Javier, Villaseñor José, Llanos Javier, Rodríguez Luis, Fernández-Morales Francisco Jesús
Chemical Engineering Department, University of Castilla-La Mancha, ITQUIMA, Avenida Camilo José Cela s/n, 13071, Ciudad Real, Spain.
Department of Plant Production and Agricultural Technology, School of Agricultural Engineering, University of Castilla-La Mancha, Ronda de Calatrava, s/n, 13003. Ciudad Real, Spain.
J Environ Manage. 2022 Dec 1;323:116251. doi: 10.1016/j.jenvman.2022.116251. Epub 2022 Sep 23.
The aim of this study was to study and model the bioleaching of abandoned mine tailings at different pulp densities 1-20% w/v by using an autochthonous mesophilic microbial culture. Because of the importance of the ferrous-iron oxidation as sub-process on the bioleaching of sulphide mineral ores, the ferrous-iron oxidation process by the autochthonous microbial culture was studied at different ferrous-iron concentrations. A mathematical model fitted to the experimental results and the main kinetic and stoichiometric parameters were determined, being the most relevant the maximum ferrous-iron oxidation rate 5.1 (mmol Fe/mmol C·h) and the biomass yield, 0.01 mmol C/mmol Fe, values very similar to that of mixed cultured dominated by Leptospirillum strains. This autochthonous culture was used in the bioleaching experiment carried out at different pulp densities, obtaining a maximum metal recovery in the tests carried out at 1% w/v, recovering a 90% of Cd, 60% of Zn, 30% of Cu, 25% Fe and 6% of Pb. Finally, the different leaching mechanisms were modelled by using the pyrite as ore model obtaining a bioleaching rate of 0.316 mmol Fe/(L·h) for the direct mechanisms and a bioleaching rate for the indirect and cooperative leaching mechanisms of 0.055 Fe/(L·h).
本研究的目的是利用本地嗜温微生物培养物，研究并模拟不同矿浆密度（1-20% w/v）下废弃尾矿的生物浸出过程。由于亚铁氧化作为硫化矿生物浸出的子过程具有重要意义，因此研究了本地微生物培养物在不同亚铁浓度下的亚铁氧化过程。拟合实验结果得到了一个数学模型，并确定了主要的动力学和化学计量参数，其中最相关的是最大亚铁氧化速率5.1（mmol Fe/mmol C·h）和生物量产量0.01 mmol C/mmol Fe，这些值与以钩端螺旋菌属菌株为主的混合培养物非常相似。将这种本地培养物用于在不同矿浆密度下进行的生物浸出实验，在1% w/v的实验中获得了最大金属回收率，镉的回收率为90%，锌为60%，铜为30%，铁为25%，铅为6%。最后，以黄铁矿为矿石模型对不同的浸出机制进行了模拟，直接机制的生物浸出速率为0.316 mmol Fe/(L·h)，间接和协同浸出机制的生物浸出速率为0.055 Fe/(L·h)。
