Abstract:
To solve the problems of the high-grade steeply inclined ultra-thin gold ore body during deep mining, including difficulty in recovering near-shaft overlying resources, severe resource overlay by traditional safety pillar demarcation methods, and shaft collapse caused by historical open-stope mining, this study conducted research on the safe and efficient mining of near-shaft overlying ore bodies by means of numerical simulation, theoretical calculation, and on-site monitoring. The study optimized the demarcation of safety pillars using the safe depth method, taking the critical mining depth as 72.17 m and reducing the scope of safety pillars at the 17th mining level to 45 m. It proposed the upward horizontal slicing lightweight energy-absorbing paste filling mining technology, which was verified by numerical simulation: After filling, the maximum displacement of the shaft was ≤1 mm; the blasting vibration calculation obtained a vibration velocity of 0.32 cm/s, far lower than the limit of 20 cm/s; on-site monitoring indicated a shaft deformation of ≤1 mm. Application in the 17364 Test Stope shows that this technology recovers 50.01 kg of gold metal and creates an additional economic benefit of 31.064 million yuan. It has also been successfully promoted to similar stopes such as 9346. The research results provide a technical path for the recovery of near-shaft overlying resources of steeply inclined ultra-thin ore bodies under deep complex geological conditions and have important practical value for extending the mine service life and ensuring shaft safety.