中等嗜热菌群协同脱除高硫铝土矿中的硫

Bio-desulfurization of high-sulfur bauxite by designed moderately thermophilic consortia

选用氧化特性不同的6株中等嗜热菌,构建4组共培养菌群,用于一水硬铝石型高硫铝土矿的摇瓶脱硫实验。对筛选出的高效菌群,分析其在高硫铝土矿脱硫过程中的脱硫行为,并采用SEM、XPS、XANES等技术手段分析含硫矿物氧化过程中的表面形貌和中间产物。结果表明:铁、硫氧化混合菌群比亚铁氧化菌群和硫氧化菌群具有更强的氧化能力,脱硫15d后矿石中硫含量下降到0.29%,满足拜耳法生产氧化铝的原料要求。在氧化过程中,含硫矿物表面出现单质硫和黄钾铁矾,但这些中间产物并未成为脱硫的阻止因素。最终氧化产物是硫酸盐。

Four microbial consortia were constructed using six moderately thermophilic and their ability to bio-desulfurization of high-sulfur bauxite were studied in flask scale. The most efficient consortia's behavior during the process of high sulfur bauxite desulfurization was measured. The surface microcosmic appearance and speciation of bauxite were characterized by means of SEM, XPS and XANES. The results show that consortia containing sulfur- and iron-oxidizing moderately thermophilic acidophiles provide more rapid bio-oxidation rate than consortia containing iron-oxidizing or sulfur-oxidizing microorganisms only. After Bio-desulfurization 15 d, the sulfur content of bauxite decreases to 0.29%, then the bauxite can be used as raw material in Bayer process of alumina production. The mineral surface is partially covered by intermediate products of the elemental sulfur and jarosite, causing no passivation. The end product of pyrite oxidation is sulfate.