【作者】 李启月；

【导师】 李夕兵；

【作者基本信息】 中南大学 ， 采矿工程， 2008， 博士

【摘要】 深孔采矿作为地下采矿生产中最流行的一种安全、高效、低成本和大规模的采矿方法在许多低品位矿山和厚大矿体中被采用,然而这种采矿方法所采用的深孔爆破技术却始终围绕着爆破破岩和防止爆破破坏两个对立的问题展开着。一方面,要保证破碎质量,满足出矿要求;另一方面,大爆破所形成的空气冲击波和地震波对矿山设施的破坏往往是一大生产问题,而且深孔崩矿的优越性会因超负荷爆破所致的贫化率高、大块多、岩层破裂和矿山安全问题而被抵消,更有甚者,矿山可能因严重破坏和生产损失而停产。深孔爆破所衍生的破岩和破坏都是爆破能作用的结果,在爆破过程中,最初施加于矿岩上的是柱面应力波能,后期作用的是似静态气体压力的膨胀能。矿岩在该应力波作用下将爆破能传递给矿岩并转化为矿岩的动能和变形能,当矿岩所吸收的能量大于某一值时,矿岩将发生破碎,从而有一部分能量用于矿岩的裂纹扩展和新表面的形成,而余下的能量就转化为弹性地震波。之后成破碎松散体的矿岩在静态气体作用下移动,静态气体的膨胀能一部分转化为矿岩的移动能和抛掷能,其移动速度和加速度则主要取决于气体压力和抵抗线大小,而余下的膨胀能量就转化为空气冲击波。为保证破碎质量和控制爆破破坏,有必要对矿岩深孔爆破能量转化与控制进行研究,本论文以具体工程的实际问题为背景,综合运用室内试验、数值试验、理论分析、现场试验等手段和方法,以矿岩深孔爆破破岩能量分析为研究课题展开了系统研究,取得了一系列的理论成果,并将该成果运用到黄沙坪矿多金属开采的深孔爆破中。本文的主要研究成果及创新点如下:(1)根据矿岩深孔爆破应力波的波形和延续时间在不同爆破条件下和在不同的爆破作用范围内不同的特点,通过对具有不同波形的应力波在矿岩中的能量耗散的理论分析,得出矿岩在这些波形作用下的破坏形式和能量耗散规律,并通过室内试验获得具体矿岩在爆破应力波单次作用破坏、累积作用破坏和无损伤作用的能量准则。(2)采用数值模拟技术,研究了矿岩爆破破碎机理,得到了冲击剪切是矿岩爆破破碎的主因且矿岩冲击剪切破坏是径向运动速度梯度所致的结论;基于能量转化与守衡原理,建立了基于动能的矿岩爆破破碎块度分布模型。(3)运用数值试验研究了不同炸药、不同抵抗线和不同炮孔密集系数下矿岩爆破的能量密度分布,根据能量准则和块度分布模型,进行了炸药的选型、抵抗线和炮孔密集系数的优化。(4)运用相似理论,推导出柱状耦合药包爆破几何相似准则,得到了柱状耦合药包爆破孔网参数的规范化形式,揭示了不同孔径下爆破抵抗线间和不同孔径下炮孔密集系数间的内在相似关系,从而解决了利用浅孔来优化深孔爆破参数的技术问题。更多还原

【Abstract】 Deep-hole mining technology is often considered as a safe, effective and economical underground mining method, so it is extensively used in most of mines, especially in the mines with low grade and huge ore bodies. The key technical issue related to deep-hole mining is exploding technology, in which two opposite aspects must be taken into account: breaking rock mass by exploding and preventing damage from exploding. That is, the fragementation of rock mass after breakage must satisfy the demands of ore withdrawal and the damage to the mine’s equipments must be controlled to the minimum. Thus, the advantages of deep-hole mining will be counteracted by the following problems: high ore dilution, excessive chunk, breakage of rock stratum and lessening of safety. The situation will be worse in case of overload exploding. Sometimes, the mine may have to be shutdown because of serious exploding breakage.Breakage and damage to rock is resulted from exploding energy. At the beginning of exploding, cylinder stress wave energy was brought into the rock, then expanding energy of static-gas-like pressure. Exploding energy was transferred to the kinetic energy and transformative energy with the stress wave to rock. When the rock absorbed enough energy, it will be broken. Furthermore, a part of energy will be consumed in the expanding of cracks and the shaping of new surfaces, and the rest will be transferred into elastic earthquake wave. Incompact rock caused by exploding moves with the function of static gas. A part of expanding energy caused by static gas was transferred into moving energy and slinging energy. The moving speed and acceleration are mainly depends on the stress of gas and the size of burden, and the rest expanding energy was transferred into shocking wave of air.In order to maintain the exploding quality and to minimize the damage, it is necessary to analyze deep-hole rock breaking energy transferring and controlling. In this dissertation, indoor experiments, numerical experiments, theoretical analysis, in site experiments are synthetically used to analyze real engineering and practical problems. With research to deep-hole exploding energy, a series of theoretical results were achieved, and the results were used in deep-hole exploding of Huangshaping multi-metal mining. In the dissertation, main studying results and innovation are as follows:(1)According to the characteristics that the shape and duration of deep-hole exploding stress waves are distinct in different conditions and ranges, through theoretical analysis to energy consuming of stress wave of different shapes, breaking models and the rules of energy consuming were achieved. And through indoor experiments, the once-breaking, cumulative breaking and no-damage rules of the blasting stress wave of specific rocks were achieved.(2)After the analysis to the breaking mechanism of rock exploding by numerical simulation, the new view that the shape of rock exploding fragmentation is impulsion cutting breaking was made. And the fragment size distribution model which is based on energy transformation and conservation was built.(3)Research to the density of energy distribution of different explosive, different burden and different the density coefficient of holes were made by numerical simulation, and according to the energy rules of rock exploding fragmentation and the energy model, the type of explosive, burden and the density coefficient of holes were optimized, therefore, a new method that solve problems by numerical simulation was come out.(4)The exploding geometry similarity rules of cylindric charge were made, and the normative types of exploding parameters of coupling cylindric charge were achieved. The similarities between burdens and the similarities between density coefficient of holes with different diameters of holes were opened out, and the technological issues that optimize deep hole exploding parameters by shallow holes were solved.更多还原