Energy Analysis Of Rock Fragment By Deep Hole Exploding And Its Application

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.