黑曲霉浸出高碱性氧化铜尾矿研究

发布时间：2018-05-24 03:08

  本文选题：铜尾矿 + 黑曲霉　； 参考：《南华大学》2015年硕士论文

【摘要】：尾矿中含有大量的可利用金属。从尾矿中提取有价金属,对减少尾矿中重金属对环境的影响及提高资源的二次利用具有重要意义。本文旨在研发一种铜尾矿的生物浸出方法。以湖南某高碱性氧化铜尾矿为研究对象,研究了黑曲霉发酵液浸出和黑曲霉直接浸出两种浸出体系下的铜尾矿浸出行为,取得的研究成果如下:首先,开展了黑曲霉发酵液浸出实验,研究了温度、马铃薯-蔗糖含量、接种量和发酵时间对发酵液中黑曲霉菌丝球形态的影响,并利用不同菌丝球形态的发酵液浸出铜尾矿。结果表明:菌丝球直径越小,铜的浸出率越大。在温度30℃,接种量0.8%(OD600=0.1),马铃薯-蔗糖含量30%,发酵时间65 h的条件下,形成的菌丝球直径最小,数量最多。利用此条件下的发酵液在30℃,180 r·min-1条件下浸出3 d,铜的浸出率可达到83.25%。其次,进行了黑曲霉直接浸出铜尾矿实验,研究了培养时间、培养基成分、接种量、温度、转速和矿浆浓度等因素对黑曲霉的菌丝形态以及铜浸出的影响。结果表明:黑曲霉-铜尾矿菌丝球的形成可降低浸出液的粘度,提高浸出率。当培养时间为7 d,培养基中蔗糖含量为20 g·L-1,接种量为0.02%(OD600=1.0),培养温度为25℃,摇床转速为180 r·min-1和矿浆浓度为5%(v/w)时,形成的黑曲霉-铜尾矿菌丝球粒径小,个数多,且此条件下,铜的浸出率达到最大为89.45%。最后,研究了黑曲霉-铜尾矿菌丝球的结构和形成过程。结果表明,黑曲霉与铜尾矿共同培养时黑曲霉-铜尾矿菌丝球的形成分为三个阶段:黑曲霉孢子发芽形成菌丝;形成的菌丝在外力作用下以晶核为中心向外延伸生长,包裹铜尾矿形成黑曲霉-铜尾矿菌丝球;培养基内营养成分变化,菌丝球自溶。黑曲霉-铜尾矿菌丝球的结构为三层,外层为黑曲霉菌丝、中间为铜尾矿、内部为空壳的核-壳结构。
[Abstract]:The tailings contain a large amount of available metals. The extraction of valuable metals from tailings is of great significance in reducing the environmental impact of heavy metals in tailings and improving the secondary utilization of resources. This paper aims to develop a bioleaching method for copper tailings. Taking a high alkaline copper oxide tailings in Hunan as the research object, the leaching behavior of copper tailings in two leaching systems of Aspergillus Niger fermentation liquid and Aspergillus Niger was studied. The results are as follows: first, The effects of temperature, potato sucrose content, inoculation amount and fermentation time on the morphology of Aspergillus Niger hyphal ball were studied. The results showed that the smaller the diameter of hyphae ball, the greater the leaching rate of copper. Under the conditions of temperature 30 鈩，

本文编号：1927447