Bio-desilication of rutile concentrate and analysis of community structure in bio-desilication reactor

金红石精矿的生物脱硅提纯与脱硅微生物的群落结构分析（英文）

The original strain HY-7 was isolated from the bauxite mine drainage（BMD） taken from a reservoir in Sanmenxia Mine,Henan Province,China.The optimum temperature and pH for the growth of strain HY-7 were 30 ℃ and 7.0,respectively.The optimum UV radiating time was 20 s and the positive mutation rate was 23.0%.The growth curves show that strain HY-7 needs144 h to reach the stationary phase after its mutagenesis,which is 24 h earlier than that of the original strain.Sequence homology analysis indicated that this community consisted of mainly two branches：one sharing high homology with Paenibacillus stellifer and the other sharing high homology with Sporolactobacillus laevolacticus.The experimental results showed that the TiO2 grade of mtile concentrate increased from 78.21%to 91.80%and the recovery of TiO2 reached 95.24%after 7 d of bioleaching.The bio-desilication process can not only effectively improve the TiO2 grade of rutile concentrate but also meet the requirements of environmental protection.

初始菌株HY-7是从河南省三门峡矿区的铝土矿矿坑水中分离出来的硅酸盐杆菌。根据试验结果,该菌的最佳生长温度为30℃和pH值是7.0,紫外诱变改良时的最佳紫外照射时间为20s,此时的正突变率为23.0%。紫外诱变前后菌株的生长曲线对比表明,诱变后菌株达到稳定状态的时间为144 h,比诱变前提早24h。细菌的序列同源性分析表明,该群落组成主要可以分为两大支,一支与类芽孢杆菌属有较高的同源性,另一支与乳酸芽孢乳杆菌属有较高的同源性。生物脱硅试验结果表明,经过7d的生物浸出脱硅过程后,金红石精矿中TiO_2的品位从78.21%提高到91.80%,其回收率达到95.24%。该生物脱硅工艺不仅有效地提高了金红石精矿的品位,同时还很环保。