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Characteristics and schemes of box bracket filling mining method
The frame bracket filling mining method is applicable to the fact that the ore and surrounding rock are extremely unstable, the mineral deposit is extremely complicated, the roof is not allowed to collapse, and the high grade valuable ore.
This method is characterized by the use of box brackets for filling and maintenance of goafs to control the roof and surrounding rock caving, to prevent surface subsidence, to create safe working conditions for mining work and to avoid damage to surface buildings.
A typical scheme for the box bracket filling method is shown in Figure 1. The method can be divided into continuous recovery plan, long mining area recovery plan, short mining area recovery plan and vertical split strip recovery plan.
Figure 1 Box bracket filling method
1- ore body; 2-frame bracket; 3-filler; 4-stage transport lane; 5--patio
(1) Continuous recovery of the frame bracket filling method. The method is applicable to ore bodies having a thickness of less than 6 to 8 m. The feature is that the mining is carried out simultaneously on a large area, so that the pressure of the frame bracket is extremely great, and the filling work is heavy. When the length of the ore body exceeds 30 m, the ore body is divided into ore blocks for mining.
(2) Filling method of the square frame in the long mining area. It is the standard solution for the box bracket filling method for the mining of thicker deposits. Its characteristic is that the ore body is divided into 8~12m mine houses and pillars, which are harvested in two steps. The exposed area of ​​this program is smaller than the comprehensive method, and the safety when returning to the mining room is good, and the recovery rate is also high.
(3) Filling method of the frame support in the short mining area. The feature of this scheme is that the ore body is divided into 4 to 6 boxes (4.5×4.5m or 4.5×6.0m) in the short mining area. In the recovery, the "diagonal" recovery sequence is used to reduce the exposed area of ​​the stope.
(4) Vertical strips are returned to the box bracket filling method. This scheme is applicable to thick ore bodies where mining ore and surrounding rock are extremely unstable. This method minimizes the exposed area of ​​the stope. In the stage, the ore body is divided into vertical strips along the strike, and the strip width is no more than four boxes (6m) to achieve the purpose of controlling the roof.