含高压流体岩石高速卸荷粉化机理研究 | |
Alternative Title | Study on the mechanism of high speed unloading pulverization of rock containing high pressure fluid |
张耕豪 | |
Thesis Advisor | 李世海 |
2021-05-20 | |
Degree Grantor | 中国科学院大学 |
Place of Conferral | 北京 |
Subtype | 硕士 |
Degree Discipline | 工程力学 |
Keyword | 高压流体 高速卸荷 多孔介质 岩石破碎粉化机理 岩石微结构反分析 |
Abstract | 地球矿产资源丰富,世界各国每年都会开采出大量的矿石,采出的矿石必须经过破碎粉化冶炼之后才能应用于工业生产。目前矿石破碎粉化技术成本较高,能源耗费巨大。为了解决这一问题,中国科学院力学研究所提出了一种新型岩石粉化技术,即含高压流体岩石高速卸荷粉化技术。这种新型岩石粉化技术可以在毫秒量级的时间内将岩石破碎粉化为微米量级的颗粒,极大地降低矿石粉化的时间成本和能源消耗。目前对该技术的机理认识较浅,需要进行深入探究。 本文通过对含高压流体岩石高速卸荷粉化过程分析,提取可能影响岩石粉化效果的控制参量,并逐一进行研究,结果表明:岩石内部高压流体的渗流时间尺度远低于气体高速卸荷的时间尺度,两者可在时间上解耦;气体的初始压力与不同岩石的粉化效果之间存在特定阈值,气体压力低于该阈值粉化效果较差,高于该阈值粉化效果陡然上升,然后再增加气体压力,岩石粉化效果无明显变化;在保证岩石渗流稳定的情况下,岩石特征尺寸对粉化效果没有明显影响。该结论为新型岩石粉化技术从实验室小尺度研究向大尺度方向发展提供依据;在岩石内孔隙尺寸等其他条件相同的情况下,岩石粉化效果随着孔隙率的增加而提升,当孔隙率超过某一值,岩石粉化效果随孔隙率的变化明显减缓。最后,通过数理统计的方法,结合已有的实验数据,通过理论推导,反分析出岩石内部的颗粒尺寸和强度的随机分布,从而实现了从岩石粉化到岩石内部微结构的反分析。 本文首先对含高压流体岩石高速卸荷粉化的内在机理进行研究,明确了岩石发生粉化的内在原因,提取了影响粉化效果的控制参量,然后通过实验与数值模拟的方法探讨了岩石自身的特性、外界实验条件等控制参量对岩石粉化效果的影响,最后结合岩石粉化实验与理论推导,反分析出岩石内部的微结构。希望本文的工作为含高压流体岩石高速卸荷粉化技术的发展做出贡献,并为日后相关研究提供参考。 |
Other Abstract | The earth is rich in mineral resources, the world will be mined every year a large number of ore. The mined ore must be crushed and smelted before it can be used in industrial production. The existing ore crushing and pulverization technology has high cost and huge resource consumption. In order to solve this problem, the Institute of Mechanics, Chinese Academy of Sciences proposed a new type of rock pulverization technology, which is the rock containing high pressure fluid is broken and powdered by unloading confining pressure at high speed. This new type of rock pulverization technology can pulverize rock into micron sized particles in millisecond time, which greatly reduces the time cost and energy consumption of ore pulverization. However, the mechanism of the new rock pulverization technology is not clear enough and needs to be further explored. Therefore, the mechanism and law of new rock pulverization are studied in this paper. In this paper, the process of rock containing high pressure fluid is powdered by unloading confining pressure at high speed is analyzed, and the control parameters that may affect the effect of rock pulverization are extracted and studied one by one. The research shows that: The time scale of high-pressure fluid flow in rock is much lower than that of high-speed gas unloading, can be decoupled in time. There is a specific threshold between the initial pressure of gas and the pulverization effect of different rocks. When the gas pressure is lower than the threshold, the effect of rock pulverization is poor. When the gas pressure is higher than the threshold, the effect of rock pulverization rises abruptly. When the gas pressure is higher than the critical value, the crushing effect increases suddenly. Then the pulverization effect has no obvious change with the increase of gas pressure; Under the condition of sufficient rock seepage, the effect of rock pulverization has no obvious change when the characteristic size of rock is changed. This conclusion provides a basis for the development of new rock pulverization technology from small-scale laboratory research to large-scale research; When the pore size and other conditions are the same, the effect of rock pulverization increases with the increase of porosity. When the porosity exceeds a certain value, the effect of rock pulverization slows down obviously. Finally, through the method of mathematical statistics, according to the existing experimental data for theoretical analysis. The random distribution of particle size and strength in rock is obtained. The reverse deduction from rock crushing to internal microstructure is realized. In this paper, the internal mechanism and pulverization law of new rock pulverization technology are studied. Combined with the mechanical model of rock pulverization, the characteristics of rock itself and the influence of external conditions on the effect of rock pulverization are discussed. It is hoped that the work of this paper will contribute to the development of high-speed unloading pulverization technology of rock containing high-pressure fluid, and provide reference for future related research. |
Language | 中文 |
Document Type | 学位论文 |
Identifier | http://dspace.imech.ac.cn/handle/311007/86624 |
Collection | 流固耦合系统力学重点实验室 |
Recommended Citation GB/T 7714 | 张耕豪. 含高压流体岩石高速卸荷粉化机理研究[D]. 北京. 中国科学院大学,2021. |
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