复杂氧化铜矿碱性浸矿菌种的选育及浸出规律研究

发布时间：2018-05-20 03:23

  本文选题：复杂氧化铜矿 + 生物浸出　； 参考：《北京科技大学》2017年博士论文

【摘要】：复杂氧化铜矿石矿物组成复杂、碱性脉石含量高、结合率高、含泥量大,是典型的难处理矿石,研究开发高效处理复杂氧化铜矿资源的技术对于扩大铜矿资源的利用范围、缓解我国铜资源供需矛盾具有重要意义。本文针对高碱性复杂氧化铜矿酸浸酸耗大、易发生化学堵塞、不适用酸性细菌强化浸出以及氨浸工艺复杂、成本高等问题,通过现场取样、室内试验、机理分析等手段,围绕复杂氧化铜矿石碱性浸矿菌种的选育及浸出规律进行了研究,主要研究工作包括:(1)获得了一株异养型碱性产氨菌种。从土壤中分离出一株碱性细菌,研究了细菌菌落及菌体的形貌特征,通过16S rRNA测序确定其种属信息并将其命名为Providencia sp.JAT-1;揭示了细菌的生长代谢机制,确定了最佳生长条件为:柠檬酸钠10 g/L、尿素20 g/L、温度30 ℃C、初始pH 8、接种量20%、振荡速率180 rpm。(2)开展了浸矿菌种的驯化与诱变育种。考察了矿浆对细菌JAT-1生长代谢的抑制作用,提高了细菌对矿浆的适应性,确定了细菌浸出的适宜矿浆浓度最高为14%;开展了紫外诱变与化学诱变两阶段复合诱变育种,诱变后细菌的生长活性提升42.3%、产氨能力提升19%、浸铜能力提升了约39%。(3)研究了碱性产氨细菌浸铜的影响因素并对其进行优化。分析了浸出温度、细菌接种量、初始pH、矿浆浓度、矿石粒径、搅拌速度等因素对碱性细菌浸矿效果的影响,通过Plackett-Burman试验筛选出细菌浸铜的关键影响因素,利用Box-Behnken试验考察了各关键影响因素的交互作用对浸出过程的影响,对碱性产氨菌浸铜效果进行优化,实现了铜离子的高效浸出。(4)揭示了碱性产氨细菌浸铜行为机理。设计并开展了细菌三步骤浸矿试验,考察了一步骤浸出、二步骤浸出及代谢产物浸出下矿石的浸出效果,分析了浸出前后矿石物相、表面形貌及颗粒内部孔裂隙变化规律,基于试验结果分析了细菌直接吸附行为对浸出的影响规律,探明了细菌代谢产物对矿石的浸出作用,揭示了细菌及其代谢产物的浸出作用机理。(5)阐明了碱性细菌浸铜固液作用过程及动力学机理。探讨了碱性细菌浸铜反应过程的固液作用及矿石侵蚀机理,在考虑浸出剂浓度变化的条件下,推导了液膜控制、固膜控制以及化学反应控制的固液反应动力学方程,构建了异养型细菌浸矿反应动力学模型,揭示了产氨细菌浸出过程固液反应的控制步骤,获取了浸出反应的表观活化能。(6)提出了复杂氧化铜矿碱性细菌浸出新工艺。针对氧化铜矿石酸法堆浸工艺存在的问题,首次提出了碱性细菌堆浸新工艺,并优化了堆浸实施方案,解决了原工艺存在的技术问题,提出了细菌强化浸出技术措施,形成了复杂氧化铜矿碱性细菌浸出工艺原型。
[Abstract]:Complex copper oxide ores have complex mineral composition, high basic gangue content, high binding rate and high mud content, so they are typical refractory ores. It is of great significance to alleviate the contradiction between supply and demand of copper resources in China. Aiming at the problems of acid leaching of high alkaline complex copper oxide ore with high acid consumption and chemical blockage, it is not suitable for acid bacteria enhanced leaching and ammonia leaching process to be complicated and high cost. By means of field sampling, laboratory test, mechanism analysis and so on, this paper aims at the problems of acid leaching of high alkalinity and complex copper oxide ore. The breeding and leaching regularity of alkaline leaching bacteria for complex copper oxide ores were studied. The main research work included: 1) a heterotrophic alkaline ammonia producing strain was obtained. An alkaline bacterium was isolated from soil and its colony and morphology were studied. The species information was confirmed by 16s rRNA sequencing and named as Providencia sp. JAT-1. The mechanism of bacterial growth and metabolism was revealed. The optimum growth conditions were determined as follows: sodium citrate 10 g / L, urea 20 g / L, temperature 30 鈩，

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