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2 Irregular ore pillars should be left in the stope. The diameter of the circular pillar should not be less than 3m , and the square pillar should not be less than 2m×2m . If there are conditions, the pillar should be placed in the stone belt and the lean section; For high ore bodies, artificial pillars can be used instead of reserved pillars. The size and strength of artificial pillars should ensure the safety of the roof.
3 When the thickness of the ore body is less than the minimum recoverable thickness, the roof of the cutting roadway shall not exceed the top plate of the designed mining width.
1 The comprehensive mining method should be applied to the level of less than 5m thick ore, stable and stable production level and gentle inclined ore body mining; when the thickness is greater than 3m , it should be layered mining. When conditions are met, hydraulic drilling rigs should be adopted. Full thickness once pushed forward;