Bioresources Engineering Department, CSIR-Institute of Minerals and Materials Technology (IMMT), Bhubaneswar 751013, India.
Bioresour Technol. 2013 Feb;130:332-8. doi: 10.1016/j.biortech.2012.12.071. Epub 2012 Dec 20.
Meso-acidophilic bacterial leaching of ball mill spillage (containing chalcopyrite >80%) was carried out in an innovative two-step bioleaching method. The major drawback of meso-acidophilic bioleaching limiting industrial application is the passivation phenomenon over the ore surfaces in iron-sulfur rich environments. In the present study, we present a novel wash solution that efficiently removed the passivation layer. FTIR characterization of the bioleached sample indicated that the residues could be further leached to recover extra copper after wash solution application. XRD study indicated accumulation of sulfates (SO(4)(-)) of Na, K, Fe and oxy hydroxides of iron [FeO(OH)] in the form of jarosite outlining the passivation layer. SEM, FESEM-EDS studies indicated severe corrosion effects of the wash solution on the passivation layer. Two step bioleaching of the ore sample yielded 32.6% copper in 68days in the first interlude and post wash solution application yielded 10.8% additional copper.
两段式嗜酸细菌浸出法在创新工艺中用于球磨溢料（含 80%以上的黄铜矿）浸出。限制中试和工业应用的中温嗜酸菌浸出的主要缺点是在富铁硫环境中矿表面的钝化现象。在本研究中，我们提出了一种新型的洗涤液，可有效地去除钝化层。生物浸出样品的傅里叶变换红外（FTIR）特征表明，在用洗涤液处理后，可以进一步浸出残留物以回收额外的铜。XRD 研究表明，在洗涤液的应用过程中形成了硫酸盐（SO4(-)）、Na、K、Fe 和铁的水合氧化物[FeO(OH)]的堆积物，从而形成了钝化层。SEM、FESEM-EDS 研究表明，洗涤液对钝化层有严重的腐蚀作用。两段式矿石浸出法在第一阶段间歇浸出 68 天后获得了 32.6%的铜，在应用洗涤液后又获得了 10.8%的额外铜。
