A case study on stress relief mining and design methods for rock-salt mine

Aiming at the issue in determining the low recovery rate and poor roof stability for mining deep rock-salt, theoretical analysis was carried out. By means of introducing the stress relief mining and its implementation points, combining with theoretical analysis, the empirical formulae calculating stope structure parameters were obtained which including limit room span, size of limit equilibrium pillar and stability room pillar. Then the theory of stress relief design method was verified by trial calculating an engineering case. The results indicate that the recovery rate is significantly improved for deep rock-salt mining through optimizing to stress relief mining. It is thereafter believed that the stope structure parameters obtained by theoretical formulae can meet the requirements for mining design. The key to implement stress relief extraction safely and orderly are reasonable stope layout, matching relation of room and pillar size and reasonable selection of stoping sequence.