一株浸矿微生物的筛选及对铝土矿的除铁效果

Screening of Microorganism for Bioleaching and Its Effect of Removing Iron from Bauxite Ore

除氧化亚铁硫杆菌能够浸出金属硫化矿外,其它一些微生物也可以浸出非硫化物中的一些金属元素。在本次研究中,从铝土矿山筛选到一株真菌,编号CSJ-13#。该菌株的最适生长温度为30℃,好气生长。在以蔗糖为发酵底物的液体培养基中生长7 d,培养基的pH值由初始的6.83下降到1.87,经检测培养液中的草酸含量大于4.5 g/L,说明CSJ-13#菌株具有较强的产生有机酸的能力。在反应温度85℃、反应时间6 h的条件下,用CSJ-13#发酵液浸出含铁铝土矿,矿样中Fe2O3的含量由4.96%下降到2.87%;在CSJ-13#发酵液中添加2%的H2SO4制备成pH值为0.5左右的浸矿剂后再浸出矿样,可以浸出矿样中92.03%的杂质铁,矿样中Fe2O3的含量降到0.39%。经检测,除铁后矿样中含铝矿物晶体结构没有被破坏。研究结果表明CSJ-13#菌株对铝土矿具有较好的浸矿除铁效果。

Thiobacillus ferrooxidans can be used to leach metal sulfide minerals and some other microorganisms to leach out some metal elements from non - sulfides. In this investigation, a strain of microorganism was isolated from the soil sample of a bauxite mine, which was numbered CSJ - 13^#. It is a facultative aerobe and the most suitable temperature for its growth is 30 ℃. When it was cultivated in the culture medium containing sucrose as the fermentation matrix for 7 days, the pH value of the medium was reduced from 6.83 to 1. 87 and the content of oxalic acid in the fermentation filter was greater than 4.5g/L, indicating that CSJ - 13^# strain has a strong ability to produce organic acid. Iron - containing bauxite ore was bioleached in CSJ - 13^# fermentation filter at a reaction temperature of 85 ℃ and for a reaction time of 6 hours, the Fe2O3 content in the bauxite sample was reduced from 4.96% to 2.87%. When CSJ - 13^# fermentation filter that had a pH value of about 0.5 after the addition of 2% H2SO4 was used in the leaching, 92.03% impurity iron could be leached out and the Fe2O3 content in the bauxite sample was reduced to 0.39%. The testing showed that the crystalline structure of the aluminum -containing minerals was not destroyed after iron removal, illustrating that CSJ - 13^# strain has a good effect of removing iron in the bioleaching of bauxite ore.