Geomechanics Analysis of the Phosphate Ore Mining Using the Hoek-Brown Model

Abstract

ABSTRACT Phosphate rock is an essential non-renewable resource for both food production and phosphorus chemical production. Located in Yichang City, China, the Houping Phosphate Mine (HPM) poses significant challenges due to its complex topography and geological structures. In this study, we conducted a geomechanical analysis of the mining layer at HPM utilizing the Hoek-Brown model. First, we calibrate the Hoek-Brown parameters through uniaxial compression tests in FLAC3D. Then, we calculate the stress distribution of the rock mass around the stope, the subsidence and displacement law of the roof and floor, and the plastic zone distribution. We find that the shallow-hole room-pillar method with anchor roof protection has poor pillar stability, while the filling method is more stable, lastly. Our results offer valuable insights into efficient phosphate ore mining practices and provide technical support through numerical calculations. INTRODUCTION Phosphate rock is not only an important chemical mineral material but also a non-renewable and irreplaceable resource. With much mining in recent years, the shallow phosphate resources have been gradually exhausted, and the mining of underground phosphate layers with larger buried depths has become the focus of research, one of the biggest problems is the mining research of gently inclined medium-thick ore bodies underground. Underground mining will form goaf, goaf destroys the initial stress balance of the mine, redistributes its internal stress, affects the stability of slope rock mass, and cause a series of engineering geological disasters, such as surface subsidence, caving, landslide, etc. In 1980, unreasonable mining of the Yanchihe phosphate Mine in Yuan’an County, Hubei Province led to the collapse of the mountain, which destroyed and buried the entire mining area, resulting in 284 deaths and heavy losses (Li et al., 2016). In order to prevent the occurrence of similar accidents, we should do the safety analysis of mining in advance to ensure the safety of people's lives and property.