嗜酸氧化亚铁硫杆菌和嗜酸氧化硫硫杆菌联合浸出高锡多金属硫化矿

摘要

高锡多金属硫化矿选冶过程中,硫化矿的存在严重影响了锡的回收率,目前国内外对锡矿生物法脱硫的报道极少,针对上述问题,研究采用嗜酸氧化亚铁硫杆菌和嗜酸氧化硫硫杆菌联合浸出高锡硫化矿.通过摇瓶实验考察嗜酸氧化亚铁硫杆菌、嗜酸氧化硫硫杆菌纯菌及混合菌对锡矿脱硫的影响,并采用实时定量PCR技术(qRT-PCR)对生物浸出过程中2种菌的动态变化进行了分析.结果表明:混合菌浸出优于纯、菌浸出,能够有效地提高脱硫率,当pH为2.0,转速170 r/min,温度30 °C,矿浆密度为10%时,混合菌在18天内可使锡矿中的硫脱除率达到97%.混合菌浸矿初期(第6天),嗜酸氧化亚铁硫杆菌是优势菌种,所占比例为69.4%,浸矿中后期,嗜酸氧化硫硫杆菌含量逐渐上升,并成为优势菌种,在稳定期(第24天)比例达到58.3 %.以上结果为锡矿生物法脱硫技术的开发提供了一条新的思路.%The sulphide ore in tin-rich polymetallic ore severely affects the recovery of tin. At present, there are few reports about biodesulfurization of tin ores at home and abroad. In response to the above problems, Acidithiobacillus ferrooxidans and Acidithiobacillus thiooxidans were used in the present study to bioleach tin-rich sulphile mineral. The effects of pure and mixed cultures on the biodesulfurization of the tin ore were investigated in shake flask experiments. And dynamics of the two species in the mixed culture were analyzed through the method of quantitative real-time-PCR(qRT-PCR) .The results showed that mixed bacteria leaching was better than pure bacteria one and could effectively increase desulfurization rate of the tin ore, so the de sulfurizaiton rate reached 97%on the 18th day (pH 2.0, 30℃and 170 rpm). On the early sixth day of leaching, Acidithiobacillus ferrooxidans accounted for 69.4 % of the total biomass. In the late stage, the content of Thiobacillus ferrooxidans increased gradually and became the dominant strain, which reached 58.3%in the stable stage (the 24 th day). The above result provides a new idea for the development of biodesulfurization in tin mine.