气升式反应器中细菌氧化预处理 难浸金精矿的浸出参数优化

依据三相内循环流化床结构模型, 设计了实验室规模的气升式生物反应器, 用于高砷难处理金精矿的细菌氧化预处理。从酸性矿坑水中筛选到一种中度嗜热混合菌, 驯化后可在45 ℃, pH值1.2, As(As³⁺和As⁵⁺)浓度15 g/L条件下良好生长, 并且对难浸金精矿具有较好的氧化浸出能力。在气升式反应器中采用驯化后的混合菌氧化浸出高砷难浸金精矿, 设计正交实验研究矿物粒度、矿浆浓度、反应器充气量和初始pH值对浸出的影响, 结果得出矿物粒度-37 μm, 矿浆浓度5%, 充气量4 L/min, 初始pH值1.2为该反应器最佳浸出参数组合, 在此条件下高砷金精矿砷脱除率可达到95%。

Optimum Parameters for Bacterial Pre-oxidation of Refractory Gold Concentrate in an Airlift Reactor

Structural model of gas-liquid-solid three-phase internal circulating fluidized bed was adopted to design a laboratory-scale airlift bio-reactor used for bacterial pre-oxidation of refractory gold concentrate. A mixed culture of moderately thermophilic was collected from acid mine drainage, and, after adaptation, it showed good capability to oxidize refractory gold concentrates at 45 ℃ in a pulp with a pH value of 1.2 and an arsenic content of 15 g/L (As³⁺ and As⁵⁺). The adapted culture was used for pre-oxidation of refractory gold concentrate, and an orthogonal experiment was performed to investigate the influence of particle size, pulp density, aeration rate and initial pH on leaching effect. The results show that, by adopting optimum parameters such as particle size of -37 μm, pulp density of 5%, aeration rate of 4 L/min and initial pH value of 1.2, the arsenic leaching rate can achieve 95%.