【作者】 王鑫；

【导师】 林海；

【作者基本信息】 北京科技大学 ， 矿物加工工程， 2017， 博士

【摘要】 含钒石煤作为一种重要的钒矿资源,在我国分布广泛且储量丰富。石煤中钒多以类质同象形式赋存于钒云母的晶格中,结构较稳定。传统火法焙烧提钒工艺存在环境污染严重或酸浸过程耗酸量高等问题。基于此,本文以湖北郧西某含钒石煤为研究对象,采用氧化亚铁硫杆菌(At.f)和胶质芽孢杆菌(B.M.)浸提石煤中钒,研究了细菌对钒的浸出工艺条件及不同强化方法对含钒石煤浸出的影响规律。主要研究结果如下:研究获得了At.f对含钒石煤的最佳浸出工艺条件:初始pH值2.0、矿浆浓度为20g/L、接种量10%、初始Fe2+浓度12g/L,30d钒浸出率为47.56%;获得了 B.M.对含钒石煤的最佳浸出工艺条件:pH值6.0、矿浆浓度为20g/L、接种量10%、以蔗糖为碳源,添加量为20g/L,30d钒浸出率为44.31%。在此基础上进行了 B.M.不同诱变方法的研究,发现最佳诱变方法为紫外诱变,诱变菌种的草酸和柠檬酸代谢量分别比诱变前提高了 37.67%和33.01%,钒浸出率提高了 7.86%。研究发现,采用“空白焙烧预处理含钒石煤”强化细菌浸出效果,B.M.和At.f对钒浸出率分别可达92.62%和60.63%,较未采用强化处理工艺,钒浸出率分别提高了 48.31%和13.07%。对含钒石煤进行了热力学、SEM、FTIR及XRD分析,发现有机质、黄铁矿和钒的氧化反应在热力学上均可以自发进行,且钒云母铝氧四面体的结构失稳、基本构成单元发生畸变和垮塌且赋存于残渣态的钒含量降低,是微生物浸钒的主要机制。研究了不同浸出不同工艺,发现含钒石煤原矿及空白焙烧预处理后含钒石煤以及菌种的作用顺序等对钒的浸出率影响较大,钒浸出率大小顺序为:B.M.+At.f(94.27%,原矿焙烧)>B.M.(92.62%,原矿焙烧)>Atf.+R.M.(85.54%,原矿焙烧)>Af.f(60.63%,原矿焙烧)>At.f(47.56%,原矿不焙烧)>B.M.(44.31%,原矿不焙烧)>酸浸(42.37%,原矿焙烧)>水浸(18.36%,原矿焙烧)。At.f浸出过程中,钒云母表面逐渐被黄钾铁矾覆盖而形成钝化层,阻碍了微生物及其代谢产物与钒云母颗粒的作用,影响其对钒的浸出效果。首先采用B.M.进行浸出,而后采用At.f进行浸出,可以避免At.f浸出过程中产生的黄钾铁矾对浸出效果的影响。论文的研究成果对于采用微生物浸出含钒石煤具有重要的指导作用,可为低品位含钒利用提供一定的理论基础和依据。更多还原

【Abstract】 As one of important of vanadium mineral resource,the total reserve of vanadium-bearing stone coal is abundant.It is widely distributed in China.Vanadium is as isomorphism hosting in the crystal lattice of muscovite.This lattice structure is very hard to be broken down.The traditional roasting extraction processes have lots of prooblenms,such as high consumption of acid reagents and serious environment pollution.In this paper,the recovery of vanadium from vanadium-bearing stone coal using bioleaching technology was mainly researched by At f and B.M..We focused on two important scientific issues,which were the optimum bioleaching conditions and various strengthening principles.The main research results are:The study showed that the maximum leaching rate of vanadium was achieved 47.56%after 30d under the optimum conditions of initial pH 2.0,20g/L of pulp density,10%inoculums,12 g/L of initial Fe2+ using At.f.The maximum leaching rate of vanadium was achieved 44.31%after 30d under the optimum conditions of initial pH 6.0,20g/L of pulp density,10%inoculums,20 g/L of initial sugar using B.M..The mutation test of B.M.showed the best mutation method was utraviolet mutagenesis.The vanadium extraction with the mutant bacteria was increased about 7.86%;the content of metabolites of oxalic acid and citric acid was increased about 37.67%and 33.01%,respectively.The technology of thermal pretreating vanadium-bearing stone coal can strengthen the bioleaching process.The leaching rate of vanadium using B.M.and At.f was 92.62%and 60.63%,respectively.Compared with the bioleaching raw ore,the leaching rate of thermal pretreated stone coal was increased about 48.31%and 13.07%,respectively.Thermodynamic,SEM,FTIR and XRD analysis was carried out,and found that the oxidation reaction of organic matter,the pyrite and vanadium was spontaneous reaction,the layered structure of muscovite collapses and the content of residual fraction of vanadium decrease.It is the main mechanism of bioleaching of vanadium.The raw ore and roasted stone coal was leached by different bioleaching process,and the order of leaching rate is B.M.+At.f(94.27%,roasted stone coal)>B.M.(92.62%,roasted stone coal)>At.f+B.M.(85.54%,roasted stone coal)>At.f(60.63%,roasted stone coal)>At.f(47.56%,raw ore)>B.M.(44.31%,raw ore)>acid leaching(42.37%,roasted stone coal)>water leaching(18.36%,roasted stone coal).The surface of muscovite particles was covered with jarosite during the bioleaching of jarosite,which prevented the interaction beteen bacteria or its metabolite and mineral particles.The first leaching process was acted using B.M.,followed with At.f.It could avoid the inhibition effect of passivation layer on bioleaching efficiency.The results of our results can play a guiding role for the microbial technology of leaching vanadium-bearing stone coal and provide strong theoretical basis for utilization of low grade vanadium-bearing stone coal.更多还原