A METHOD OF DEVELOPING ORE DEPOSITS

The method of ore deposits development includes sinking of preparatory and complex of rifling workings inside the excavation block massif, undercutting of the excavation block to form a horizontal undercutting space, stepwise advance weakening of the excavation block massif, stepwise self-collapse of the block and stepwise release of collapsed ore through the bottom outlet workings. Undercutting of the excavation block is carried out from the center to its flanks by sequential blasting of explosive wells drilled from the undercutting drift in the lower part of the excavation block with the formation of a horizontal undercutting space with dimensions crosswise to the strike equal to the deposit thickness and along the strike, equal to the value of the maximum permissible equivalent horizontal exposure run, with a further increase in the size of the horizontal undercutting space along the length at all subsequent stages to the boundaries of the excavation block with a simultaneous increase in the area of the horizontal undercutting space in accordance with the area of the excavation block. At the same time, the excavation block massif is gradually weakened both in length and height with its gradual self-collapse with the corresponding formation of complete natural equilibrium arches, and for the subsequent formation of complete natural equilibrium arches, the stages and each subsequent stage until contact with the collapsed rocks is achieved with an increase in the length and height of each subsequent complete arches formed at the height of the excavation block greater than 25-30 m. Additional strengthening of the weakening of the massif of the excavation block along its long side by blasting rod holes drilled parallel to the contact between the massif of the excavation block and the rocks of the underlying side from the outlet workings of the delivery drift, driven in the underlying side of the deposit at the same height and every next 10-12 m in height, depending on the height of the excavation block. They provide a specified coefficient of loosening and lumpiness of the collapsed mass of the excavation block and a phased release of collapsed ore through the bottom outlet workings when complete natural equilibrium arches are formed and each subsequent one with additional release of collapsed ore left on the lying side of the deposit through the outlet workings of the delivery drift sinking in the lying side of the deposit and every next 10-12 m in height d