Sulfur-enhanced reductive bioprocessing of cobalt-bearing materials for base metals recovery
Sulfur-enhanced reductive bioprocessing of cobalt-bearing materials for base metals recovery
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DOI：
10.1016/j.hydromet.2020.105396
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发表时间：
2020-08-01
期刊：
影响因子：
4.7
通讯作者：
Johnson, D. Barrie
中科院分区：
文献类型：
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作者：
Santos, Ana Laura;Dybowska, Agnieszka;Johnson, D. Barrie
热带和亚热带地区丰富的褐铁矿红土矿是一种大部分未开发的钴资源。利用嗜酸微生物催化铁和锰矿物的还原溶解，对氧化矿石以及尾矿和加工残渣等废料进行生物处理，是提取与这些矿床相关的有价值贱金属的一种环境友好的替代方法。这项工作描述了实验室规模实验的结果，其中五种含钴材料、三种原生褐铁矿红土矿和两种加工残留物（滤尘和矿渣）均来自希腊的矿山和加工厂，在还原条件下进行生物浸出由嗜酸菌群（使用元素硫作为电子供体）在pH 1.5和35摄氏度的搅拌罐生物反应器中进行。虽然目标金属钴从所有五种材料中成功地进行了生物浸出（30天内40-50%），但其他一些金属的浸提变化更大（例如铁的2 - 48%）。可溶性钴的浓度高度相关，在大多数情况下，与锰，在协议的发现，钴主要驱逐锰（IV）矿物。酸的消耗量在矿物样品之间也有很大差异，在3和67摩尔H2SO 4 g（-1）提取钴之间。生物处理前后的三个褐铁矿样品的综合矿物学分析揭示了矿石之间的显着变化，并表明元素和矿物学的变异性可以极大地影响其对还原生物浸出的适应性。
The abundance of limonitic laterite ores in tropical and sub-tropical areas represents a large, and mostly unexploited, cobalt resource. Bioprocessing oxidised ores, and also waste materials such as tailings and processing residues, using acidophilic microorganisms to catalyse the reductive dissolution of iron and manganese minerals, is an environmentally benign alternative approach of extracting valuable base metals associated with these deposits. This work describes results from laboratory-scale experiments in which five cobalt-bearing materials, three primary limonitic laterite ores and two processing residues (filter dust and slag), all sourced from mines and a processing plant in Greece, were bioleached under reducing conditions by a consortium of acidophilic bacteria (using elemental sulfur as electron donor) in stirred tank bioreactors at pH 1.5 and 35 degrees C. Whilst the target metal, cobalt, was successfully bioleached from all five materials (40-50% within 30 days) the extraction of some other metals was more variable (e.g. between 2 and 48% of iron). Concentrations of soluble cobalt were highly correlated, in most cases, with those of manganese, in agreement with the finding that cobalt was primarily deported in manganese (IV) minerals. Acid consumption also differed greatly between mineral samples, ranging between 3 and 67 moles H2SO4 g(-1) cobalt extracted. Comprehensive mineralogical analysis of the three limonitic samples before and after bioprocessing revealed significant variations between the ores, and demonstrated that elemental and mineralogical variabilities can greatly impact their amenability for reductive bioleaching.