生物浸出低品位镍铜硫化矿

Bioleaching of Low-grade Ni-Cu Sulfide Ore

阐述了氧化亚铁硫杆菌 (TF5)和氧化硫硫杆菌 (TT)浸出金川低品位镍铜硫化矿的机理、过程动力学、工艺条件和反应工程。研究表明 ,含镍磁黄铁矿的细菌浸出以细菌氧化生成的Fe3 +的作用为主 ,浸出速率受表面反应控制 ;镍黄铁矿的细菌浸出以矿物表面吸附菌的作用为主。细菌对Mg2 +离子的耐受浓度因驯化而提高 ,极限浓度可达 15～ 2 0g/L。低品位镍铜矿的细菌浸出过程中 ,pH控制、细菌的初始接种量、矿浆浓度及TF和TT的混合比是影响镍、铜、钴等有价金属元素浸出速率和最终浸出率的主要因素。优化条件下气升式和搅拌式反应器中试验表明 ,优化条件下 ,在生物浸出低品位镍铜硫化矿 ,镍浸出率可达到 92 %～ 94 % ,铜达 4 8%～ 50 % ,钴达 88%～ 91%。

Bioleaching of the low grade Ni Cu sulfide ore from Jinchuan Mine by Thiobacillus ferrooxidans (TF5) and Thiobacillus thiooxidans (TT) is investigated, and the process mechanism, kinetics, technological factors, reactor and engineering are discussed The results show that the chemical reaction of Fe 3+ play a major role in the bioleaching process of pyrrhotite containing Ni and Co, and its leaching rate is controlled by surface reaction The superiority reaction in the bioleaching of pentlandite comes from the direct action of the bacteria attached on the surface of ore particles The ions of Ni 2+ , Co 2+ , Cu 2+ and Mg 2+ in leachates affect the bacteria growth as their concentration sufficient high, and the limited concentration will be improved by adaptation, for example, 15～20 g/L of Mg 2+ is achieved for adapted TF5 The pH, the initial cell numbers of bacteria, the solid density and the mixed culture of TF5 and TT are the very important factors affected on leached Ni, Cu and Co in the bioleaching of the low grade Ni Cu sulfide ore From tests in an aerated agitating reactor and an air lifting reactor under the favorable conditions, it is indicated that the most high leaching yield, such as 92%～94% of Ni, 48%～50% of Cu and 88%～91% of Co, is achieved in the aerated agitating reactor