(1. 中国科学院过程工程研究所 绿色过程与工程重点实验室 生化工程国家重点实验室，北京 100190；
2. 中国科学院大学 化学工程学院，北京 100049；
3. 内蒙动力机械研究所，呼和浩特 010010)
摘 要: 通气动力成本过高是含砷难处理金矿的生物氧化预处理法中存在的主要问题，在不同矿浆浓度、不同反应器条件下开展含砷难处理金矿生物氧化实验，重点监测反应体系中溶解氧浓度、氧化还原电位φ、pH和砷浓度的变化；采用5 L反应器开展不同矿浆浓度实验。结果发现：25%矿浆浓度实验中溶解氧浓度低至225 μg/L，但其生物氧化过程仍可正常进行，表现为φ持续上升和pH持续下降，由此推测在生物氧化工业生产中无需维持过高的通气强度。采用80 L反应器开展25%矿浆浓度实验，结果发现，与5 L反应器实验相比，虽然其通气比更低，但得益于其导流筒带来的矿浆悬浮作用及较大的高径比，溶解氧浓度明显提高。由此推测，在生物氧化工业生产中可以采用优化反应器设计的方式，在不增加通气成本的前提下，提高矿浆中的溶解氧浓度。
关键字: 溶解氧；生物氧化；砷浓度；氧化还原电位；导流筒
（1. State Key Laboratory of Biochemical Engineering, CAS Key Laboratory of Green Process and Engineering, Institute of Process Engineering, Chinese Academy of Sciences, Beijing100190, China;
2. School of Chemical Engineering, University of Chinese Academy of Sciences, Beijing 100049, China;
3. Dynamic Machinery Institute of Inner Mongolia, Hohhot 010010, China）
Abstract:High cost on aeration is the major challenge in the biooxidation pretreatment of arsenic-bearing refractory gold ore. In present study, experiments at different pulp densities were carried out in different reactors. The variations of DO concentration, redox potential φ, pH and arsenic concentration were monitored during the biooxidation process. Firstly, experiments were carried out in a 5 L reactor at different pulp densities. The results show that the DO concentration at the 25% pulp density is significantly lower than that that at the 10% pulp density. In spite of the low DO concentration, the φ increases and the pH decreases continuously at the 25% pulp density, indicating that low DO concentration can still sustain the biological process. It is suggested that relative low aeration intensity can be used in the industrial plant for low cost on aeration. Secondly, experiments were carried out in an 80 L reactor at the 25% pulp density. The 80 L reactor has a higher ratio of H/D than that of the 5 L reactor and it is equipped with a draft-tube. It is found that the DO concentration in the 80 L reactor is obviously higher than that in the 5 L reactor though the ventilation ratio in the 80 L reactor is lower than that in the 5 L reactor. The results imply that the draft-tube and higher ratio of H/D are helpful for the increase of DO concentration in the 80 L reactor. It is suggested that optimizing design of the reactor can increase the DO concentration in the industrial plant without extra cost on aeration.
Key words: dissolved oxygen; biooxidation; arsenic concentration; redox potential; draft-tube
