Thermophilic mineral bioleaching performance: A compromise between maximizing mineral loading and maximizing microbial growth and activity
Thermophilic mineral bioleaching performance: A compromise between maximizing mineral loading and maximizing microbial growth and activity
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发表时间：
2003-03
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通讯作者：
A. Sissing;S. Harrison
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作者：
A. Sissing;S. Harrison
高温生物浸出在超过65摄氏度的温度下进行，与中温生物浸出相比，尤其是通过扩大黄铜矿等贱金属矿物的浸出范围，提供了相当大的好处。嗜热生物浸出通过一组被称为古生菌的微生物来促进，这些微生物很好地适应了极端环境。为了最大限度地利用高温生物浸出过程中搅拌槽反应器的时空利用率，在不对微生物性能产生不利影响的情况下，最大限度地增加存在的细小矿物相的负荷是可取的。在搅拌釜式反应器中，研究了固体颗粒相的装载量对金属硫酸盐细菌浸出性能的影响。重点研究了细分固相(35i？25i？？m)浓度的影响。由3%(w/v)的黄铁矿和0~24%(w/v)不同数量的石英岩组成的模型体系被用来获得不同的固体浓度。生物浸出实验表明，当总固体含量为3%~18%(w/v)时，生物浸出性能相似。当总固形物含量超过18%(w/v)(石英岩含量为15%)时，随着固形物浓度的增加，生物浸出逐渐减弱。在所研究的最高固体负荷为27%(w/v)时，仍然可以观察到生物浸出。在传质方面，在所研究的固体范围内，生物浸出过程中的氧传递势没有明显的影响。
Thermophilic bioleaching, conducted at temperatures in excess of 65i?½C, provides considerable benefit over mesophilic bioleaching, particularly through extending the extent of leaching of base metal minerals such as chalcopyrite. Thermophilic bioleaching is facilitated through a group of micro-organisms known as the Archae, well adapted to extreme environment. In order to maximize the space time utilization of the stirred tank reactor in the thermophilic bioleaching process, it is desirable to maximize the loading of the finely divided mineral phase present while not adversely affecting the microbial performance. In this paper, the effect of the loading of the solid particulate phase on the bioleaching performance of Sulfolobus metallicus was studied in a stirred tank reactor. Emphasis was placed on the effect of the concentration of the finely divided solid phase (35 i?½ 75 i?½m). A model system comprised of 3% (w/v) pyrite in the presence of varying quantities of quartzite in the range 0 to 24% (w/v) was used to obtain the different solids concentrations. The bioleaching experiments revealed similar bioleaching performance in the presence of 3 to 18% (w/v) total solids. Above 18% (w/v) total solids (15% quartzite loading), bioleaching was impaired progressively with increasing solids concentration. At the highest solids loading studied of 27% (w/v), bioleaching was still observed. In terms of mass transfer, oxygen transfer potential was not significantly influenced in the bioleaching process over the range of solids investigated.