| Magnesite ore provides many benefits for industrial production and daily life.However,in the past,unreasonable mining methods have caused a lot of waste of resources and environmental pollution.How to develop and utilize magnesite ore resources more efficiently and environmentally is an important and meaningful research subject.The high voltage pulsed liquid-phase discharge technique plays an important role in the mechanical effect.It has been studied in the field of sand removal and rock fragmentation.The selective fragmentation of this technology provides the possibility of dissociating magnesite ore from the interface to obtain magnesite ore monomer and then efficiently utilizing magnesite ore.Based on the above background,this thesis combines high voltage pulsed liquid-phase discharge technology with magnesite ore broken.Study the theory of high voltage pulsed liquid-discharge,the electrical characteristics and direct impact characteristics of the high voltage pulse liquid-phase discharge were experimentally studied under different charging voltages and different discharge gaps,and the high-speed imaging was used to completely record the discharge process.On this basis,the experiment of magnesite ore broken was carried out.Calculate the direct impact force of the discharge channel by finite element simulation software and test the tensile and compressive strength of the magnesite ore.At the same time,scanning electron microscopy(SEM),backscattering(BSD)and EDS spectrum analysis were used to analyze the broken products.The main research contents and results are as follows:(1)Based on the study of the mechanism and theoretical model of high voltage pulse liquid-phase discharge,deriving the pressure calculation formula and the energy calculation formula of the shock wave in water,combined with the distribution of the area around the plasma channel,it is clarified that the method of improving the liquid-electric breaking efficiency is to increase the force of the shock wave and reasonably place the broken material.Electrostatic field simulation analysis shows that the electric field strength at the interface of different mineral components is the largest.At the same time,the simulation results show that the selective fragmentation of liquid-phase discharge.Under the same conditions,a short discharge gap and a sharp electrode are easy to obtain better discharge effect.(2)Under the experimental conditions of charging voltage 10~25kV and discharge gap 5~15mm,the experimental study is carried out in the form of discharge impact plate.The results show that the peak current and peak pressure are positively correlated with the charging voltage and negatively correlated with the discharge gap.The impact point of the plasma channel impact plate is mainly distributed in a circular area with a radius of 5 mm in the center of the plate,and the distribution of the impact point is dense with the increase of the voltage,and the dispersion trend tends to be dispersed as the discharge gap increases.The increase in charging voltage facilitates the acceleration of streamer discharge process,thereby reducing the energy loss and obtaining a stronger impact force.(3)The possibility of magnesite ore broken is demonstrated by the mechanical performance test of magnesite ore and the simulation of the direct impact force of the discharge channel.The broken experiment was carried out under the conditions of a charging voltage of 30 kV and a discharge gap of 5 mm.Then,the broken results were analyzed.The results show that the increase in the number of discharges is beneficial to obtain more fine-grained magnesite ore.The dissociation of magnesite ore is realized along the interface of different components,and the magnesite ore monomer particles can be obtained.In this thesis,high voltage pulsed liquid-phase discharge technology is combined with magnesite ore broken.Through the study of the characteristics of high voltage pulse liquid-phase discharge and the experiment of magnesite ore broken,it provides a new idea for the efficient use of magnesite ore,also for high voltage pulse liquid-phase discharge technology provides a reference for the application in the field of breaking. |
PDF Full Text Request