(1. 中國(guó)科學(xué)院過程工程研究所 綠色過程與工程重點(diǎn)實(shí)驗(yàn)室 生化工程國(guó)家重點(diǎn)實(shí)驗(yàn)室，北京 100190；
2. 中國(guó)科學(xué)院大學(xué) 化學(xué)工程學(xué)院，北京 100049；
3. 內(nèi)蒙動(dòng)力機(jī)械研究所，呼和浩特 010010)
摘 要: 通氣動(dòng)力成本過高是含砷難處理金礦的生物氧化預(yù)處理法中存在的主要問題，在不同礦漿濃度、不同反應(yīng)器條件下開展含砷難處理金礦生物氧化實(shí)驗(yàn)，重點(diǎn)監(jiān)測(cè)反應(yīng)體系中溶解氧濃度、氧化還原電位φ、pH和砷濃度的變化；采用5 L反應(yīng)器開展不同礦漿濃度實(shí)驗(yàn)。結(jié)果發(fā)現(xiàn)：25%礦漿濃度實(shí)驗(yàn)中溶解氧濃度低至225 μg/L，但其生物氧化過程仍可正常進(jìn)行，表現(xiàn)為φ持續(xù)上升和pH持續(xù)下降，由此推測(cè)在生物氧化工業(yè)生產(chǎn)中無需維持過高的通氣強(qiáng)度。采用80 L反應(yīng)器開展25%礦漿濃度實(shí)驗(yàn)，結(jié)果發(fā)現(xiàn)，與5 L反應(yīng)器實(shí)驗(yàn)相比，雖然其通氣比更低，但得益于其導(dǎo)流筒帶來的礦漿懸浮作用及較大的高徑比，溶解氧濃度明顯提高。由此推測(cè)，在生物氧化工業(yè)生產(chǎn)中可以采用優(yōu)化反應(yīng)器設(shè)計(jì)的方式，在不增加通氣成本的前提下，提高礦漿中的溶解氧濃度。
關(guān)鍵字: 溶解氧；生物氧化；砷濃度；氧化還原電位；導(dǎo)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
