Numerical and Experimental Study on Crushing Properties of Hard Coal Using Impacting-Cutting Technique

Qiang Zhang,Cong Wang,Ying Tian,Xue-Qiu He

doi:10.1155/2022/7091553

Qiang Zhang, Cong Wang + Show 2 more

Open Access

https://doi.org/10.1155/2022/7091553

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Abstract

The reserves of high-quality coal seams have been greatly reduced in recent years, and the low efficiency of traditional cutting methods in hard coal seams has become a problem for the coal production industry. In order to improve the mining efficiency, an impacting-cutting technique was proposed in this study. A drum modification model with picks impact function was established, and crushing properties of the impacting-cutting drum at f4, f5, and f6 coal hardness were simulated using the discrete element method. The simulation results show that the impacting-cutting drum has higher coal crushing efficiency, lower drum force, and more stable cutting processes than the traditional drum. It shows that hard coal might be effectively reduced by the impacting-cutting technique to reduce the difficulty of mining, and reflected the applicability in hard coal seams. Meanwhile, a simplified test device for the impacting-cutting technique was designed. And the actual coal crushing performance was tested. The test results show that the force of the cutting mechanism in the impact mode is lower than that of the nonimpact mode, and the force is more stable. It proves that the impacting-cutting technique has a higher applicability of hard coal seams than the traditional technique.

Highlights

With the increasing proportion of complex coal seams [1,2,3,4], the efficiency of traditional mechanical coal mining methods is getting lower
Zhao et al [18] studied the influence of particle water jet parameters on rock impact depth and crushing effect based on the smooth particle hydrodynamics (SPH) method
E force of the cutting mechanism in the impact mode is reduced by 17.22% compared with the nonimpact mode, and the force is more stable. e test results are similar to the laws reflected in the simulation results. erefore, it proves that the impacting-cutting technique has a higher applicability to hard coal seams than the traditional technique

Summary

Introduction

With the increasing proportion of complex coal seams [1,2,3,4], the efficiency of traditional mechanical coal mining methods is getting lower. Laser crushing is difficult to control the energy range, and it may change the properties of coal, which will lead to a physical failure In response to these problems, an impacting-cutting technique was proposed by the author’s research team [24]. Compared with the existing methods, the impacting-cutting technique is combined with the characteristics of jet crushing to reduce the difficulty of cutting by inducing the development of internal cracks in the coal body, and the pick is still used as a carrier for applying external loads to the coal. In this way, the problem of difficulty for coal preparation is avoided. The actual performance of the impacting-cutting technique was tested from the field test, and the results of the DEM solution were verified

Numerical Simulation

Results and Analysis

Experimental Set Up

Results and Discussion

Conclusions

Disclosure