准格尔煤田煤中稀有金属富集机理的实验模拟

发布时间：2018-06-19 13:02

本文选题：准格尔煤田 + 阴山古陆　；参考：《河北工程大学》2015年硕士论文

【摘要】：准格尔煤田煤炭资源极其丰富,在其多处煤矿中发现了锂-镓-稀土等多种稀有金属富集的现象。本次研究在总结前人提出的煤中稀有金属富集的富集理论基础上,设计了相应的模拟实验,进一步验证和深化煤中稀有金属的富集理论。使用偏光显微镜、ICP-MS、XRD和XRF等多种手段对阴山地区岩石样品的岩石学特征、矿物学特征、常量元素特征、微量元素特征以及稀土元素含量特征进行了分析,并与准格尔煤田多处地区煤中的相应特征作对比。发现阴山古陆的岩石样品中主要成分为石英、长石和云母,而准格尔煤田煤中的主要矿物为高岭石、石英、方解石和黄铁矿等。根据当时的古环境和古地理条件,综合利用地质学和地球化学等知识进行了相应的模拟实验。首先使用多种酸介质,以及在古气候条件可控的pH和温度范围内进行了岩石溶解实验,随后用粘土矿物高岭土对配置的含锂溶液和含镓溶液进行了模拟吸附实验,得出了高岭土对两种稀有金属离子的吸附特征。结合准格尔煤田周围地质背景,对锂、镓和稀土的富集机理取得以下认识:(1)在pH较小的环境中,锂可以从物源区的岩石中短期大量释放出来,形成较高的含锂溶液,随后被粘土矿物所吸附,完成一次富集过程,并随粘土矿物一起进入到泥炭沼泽中。(2)镓可能随着岩石风化成铝土矿的过程中,完成一次富集过程。随后作为陆源碎屑物质的一部分进入到泥炭沼泽中。(3)模拟的自然条件下也稀土元素从岩石中释放出来,并被粘土矿物所吸附,最后进入到泥炭沼泽中。但是考虑到腐殖酸可能对稀土有更好的吸附作用,因此其富集机理还需泥炭沼泽模拟实验进行进一步验证。本次研究主要探讨了稀有金属元素从岩石释放到泥炭沼泽之前的元素迁移过程,丰富了煤型稀有金属的富集成矿理论。为下一步泥炭沼泽的模拟实验做了准备工作。
[Abstract]:The Zhunger coalfield is rich in coal resources, and many rare metals, such as lithium-gallium-rare earth, have been found in many coal mines. On the basis of summarizing the enrichment theory of rare metals in coal put forward by predecessors, the corresponding simulation experiments are designed to further verify and deepen the enrichment theory of rare metals in coal. The petrological characteristics, mineralogical characteristics, major elements, trace elements and REE contents of rock samples in Yinshan area were analyzed by means of polarizing microscope ICP-MSX XRD and XRF. It is compared with the corresponding characteristics of coal in many areas of Zhunger coalfield. It is found that quartz feldspar and mica are the main components in the rock samples of Yinshan ancient land while kaolinite quartz calcite and pyrite are the main minerals in the coal of Zhunger coalfield. According to the paleogeographic and paleogeographic conditions at that time, the corresponding simulation experiments were carried out using the knowledge of geology and geochemistry. Rock dissolution experiments were carried out in the paleoclimatic pH and temperature range using various acid media, and then simulated adsorption experiments were carried out with clay mineral kaolin for lithium and gallium containing solutions. The adsorption characteristics of kaolin to two rare metal ions were obtained. In combination with the geological background around the Zhungeer coalfield, the enrichment mechanism of lithium, gallium and rare earths has been obtained as follows: (1) in a relatively small pH environment, lithium can be released in large quantities from rocks in the source area in a short period of time to form a higher lithium solution. Then it was adsorbed by clay minerals, completed a enrichment process, and entered into the peat swamp with clay minerals. (2) Gallium may have completed a enrichment process with the weathering of rocks to bauxite. The REE was then released from the rocks as a part of the terrestrial clastic material into the peat swamp under the simulated natural conditions and then adsorbed by the clay minerals and finally into the peat swamp. However, the accumulation mechanism of humic acid may be better adsorbed to rare earths, which needs to be further verified by peat swamp simulation experiments. This study mainly discusses the migration process of rare metal elements from rock to peat swamp, which enriches the enrichment and metallogenic theory of rare metals in coal type. The preparation for the next simulation experiment of peat swamp is made.
【学位授予单位】：河北工程大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：P618.11;P618.6

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