ABSTRACT

Biochemical leaching of sea nodules using Bacillus circulans was carried in an external circulation-loop airlift bioreactor. In contrast to the slightly high recovery (92% Cu, 73% Ni, 72% Co, 38% Mn, and 17% Fe) with fine particles (<75 µm) on shake flasks in 25d, the leaching of metals using coarser lumps (1190–250 µm size fraction) were found to be 76% Cu, 69% Ni, 65% Co, 29% Mn and 12% Fe in the same duration in an air-lift reactor with airflow of 500L min⁻¹. The use of air flow assisted in retaining good metal recoveries with reduced grinding costs in the air lift reactor. Computational Fluid Dynamics (CFD) with a multiphase mixture model was used to describe the mass transfer and hydrodynamics vis-à-vis its role in improved leaching efficacy. The leach liquor was treated to eliminate iron, followed by selective extraction of copper by 10% Acorga M5640. The remaining leach liquor with Mn, Co and Ni were separated as respective salts by sulfide/carbonate precipitation.

摘要

使用环状芽孢杆菌对海结核进行生化浸出在外部循环回路气升式生物反应器中进行。与在 25 天在摇瓶上使用细颗粒 (<75 µm) 的回收率稍高（92% Cu、73% Ni、72% Co、38% Mn 和 17% Fe）相比，使用较粗的块浸出金属（1190–250 µm 尺寸分数）在气流为 500L min ^-1的气升式反应器中，在相同的时间内发现为 76% Cu、69% Ni、65% Co、29% Mn 和 12% Fe. 气流的使用有助于保持良好的金属回收率，同时降低气升反应器中的研磨成本。具有多相混合物模型的计算流体动力学 (CFD) 用于描述传质和流体动力学，以及其在提高浸出效率中的作用。对浸出液进行处理以去除铁，然后用 10% Acorga M5640 选择性提取铜。剩余的含 Mn、Co 和 Ni 的浸出液通过硫化物/碳酸盐沉淀分别作为盐分离。