含钾硅酸盐矿物的微生物浸出溶钾过程及机理研究

Many reports showed that potassium-dissolving microorganisms such as mucuos Bacillus mucilaginous,fungus, Bacillus circulans and moulds can activate and release potassium and silicon from silicate minerals. At present, there are three main methods to obtain water-soluble potassium, including physical method , chemical method and physical- chemical method. Compared with the three methods, the biological method has potential prospect with the advantages of more prfit and less pollution..Many studies have showed that these potassium- dissolving microorganisms are mainly used in bacteria fertilizers, but there are few reports on these microorganisms applied in silicate minerals processing to make available potassium. The primary cuase is that the mechanism by which potassium- dissolving bacteria release potassium from minerals is complicated and not clear, and the microbial leaching technology is in the stage of laboratory exploration..In this study, potassium-dissolving microorganisms such as silicate bacteria, aspergillus niger will be isolated from different resouces, and the strains with high effective potassium-dissolution will be singled out and be mutated in order to obtian mutants with higher potassium dissolving ability. Single and cooperative bioleaching of silicate minerals such as potash feldspar, mica by these isolates and mutants will be experimented. Meantime, bioinformatics characteristics of all tested strains such as metabolins, strains identification will be studied. All these studies aim to obtain single strian and group strains with high effective potassium dissolution..In this work, the optimum bioleaching conditions will be determined by bioleaching experiments. Chemical forms of K, Si etc.in leachates and on minerals surfaces, process mineralogy characteristics of silicate minerals will be analyzed during bioleaching. And microbial population and enviromental factors will also be determined by bioleaching experiments. All experiments mentioned above aim to ascertain bioleaching conditions of single strain and microbial population, the relationship between minerals phase transformation and enviromental factors, and then show the mechanism by which potassium-dissolving microorganisms extract potassim from silicate minerals such as potash feldspar,mica as far as possible.

溶钾微生物如黏液胶质芽孢杆菌、环状芽孢杆菌、真菌、霉菌等对硅酸盐矿物中的钾、硅有较好的活化作用，较物理与化学方法从含钾矿物提钾技术相比，可以消除由其所带来的环境危害。资料表明，目前这类溶钾微生物主要被用来制备生物钾肥，还鲜见有关微生物浸出钾硅酸盐矿物提取活性钾的相关报道，主要原因是溶钾微生物浸矿机理不明与浸矿工艺不成熟。本课题拟通过对筛选得到的不同来源菌种及其诱变菌种浸矿效果研究及分析它们的基本生物信息学特征，选育出高效专属钾长石浸矿菌种与浸种组合；通过微生物浸矿条件试验，确定硅酸盐矿物微生物浸出提钾的最佳工艺条件；通过研究不同类型菌种及组合作用下，硅酸盐矿物微生物浸出过程中矿物表面和浸出液中钾、硅及主要杂质元素的化学形态变化、工艺矿物学特征、微生物组合及环境因素的影响，探明不同微生物组合作用规律、矿物形态转化与环境因素之间的关系，揭示硅酸盐矿物微生物浸出过程中矿物形成与转化机理。

与物理与化学方法相比，钾矿物微生物浸出获得可供农作物生长的活性钾、硅的方法可以消除由其所带来的环境危害。因此，选育出高效溶钾微生物，并研发出钾矿物微生物浸出提钾工艺具有十分现实的意义。.采用微生物形态学、PCR-DGGE、16S rDNA、RFLP、物理化学诱变及摇瓶浸矿技术，筛选得到了一系列具有较好溶钾效果的细菌与真菌及其诱变菌种，探明了在浸矿过程中混合菌群的群落结构的演替规律，选育出了高效专属钾长石浸矿菌种与浸种组合；确定了钾长石微生物浸出提钾的最佳工艺条件；采用XRD、SEM、IR、EDX 、分子生物学等分析手段，基本阐明了钾长石微生物浸出过程中矿物表面和浸出液中钾、硅及主要杂质元素的化学形态变化、工艺矿物学特征、微生物种群及环境因素对浸矿效果的影响，基本揭示了钾长石微生物浸出过程中矿物形成与转化机理。.诱变菌株比对应的出发菌株的浸矿性能明细要好；组合菌种对钾矿物中的钾、硅、铝的浸出率明显要高于单一菌。.与摇瓶浸出方式相比，连续浸出方式可以显著促进“钾”细菌对富钾火成岩的风化分解，混合“钾”细菌CMR 对富钾火成岩中的K2O 、SiO2 、Al2O3 的浸出率分别到达52.36% 、33.62% 、40.55% ，而在摇瓶浸出方式中，对应的浸出率分别为30.67%、21.49%、9.91%。.生物膜可以促进钾矿物分解，而溶出金属本身及与细菌代谢产物（如，有机酸铝与Al2O3沉淀）所形成的钝化膜对各金属的溶出又有明显的抑制作用。 .细菌对不同结构矿物分解具有一定的“选择性”。细菌可使钾矿物晶体结构受到破坏的同时，一种矿物会被转变成另一种或多种矿物，形成次生矿物模块。.钾矿物可以促进细菌产草酸、酒石酸、苹果酸、柠檬酸等有机酸、氨基酸与多糖。各代谢产物对钾矿物具有一定的风化分解作用，但细菌的浸矿作用明显要强，表明细菌对矿物的浸矿作用是生物物理及化学等多种因素共同作用的结果。.本项目基本阐明了影响钾矿物微生物浸出效率的各种关键因素，其主要研究成果为开发可能实际工业应用的钾矿物微生物浸出提钾技术提供了可靠的科学依据。.