Management of goaf in Chufeng Phosphate Mine and its in-process safety monitoring

Chufeng Phosphate Mine has formed a large area of goaf during years of mining, and the pillars have been damaged.In order to avoid large-scale goaf caving and recover the remaining resources, a test panel is selected.Under the condition of continuous pillars (point pillars+artificial pillars) isolation, unstable pillars are replaced with concrete cemented filling, and the goaf is treated with a dry filling scheme.In addition, a comprehensive monitoring system integrating microseismic, displacement, stress, strain and other monitoring methods has been established to monitor the displacement of the roof, stress and strain of the pillar and cemented pillar, and microseismic events during the treatment process.The stability of the goaf is analyzed comprehensively through multiple parameters, ensuring the safety of the treatment process.The monitoring results indicate that there has been no significant stress concentration or deformation instability.