Bord and Pillar Mining: 1. Initial Development: - Bords (or Rooms): Horizontal galleries are driven into the coal seam, creating rectangular rooms called bords or rooms. - Pillars:The remaining coal within the pillars between the bords is left untouched to provide support to the overlying strata. 2. Extraction Phase: - Extraction of Coal: The coal is then extracted from the bords, leaving behind the pillars. - Pillar Size: The size and arrangement of the pillars depend on factors such as the geology of the deposit, the depth of the seam, and the desired level of recovery. 3. Support and Safety: - Roof Support: The surrounding rock is supported by the pillars, and additional roof support methods like roof bolts or other supports may be used as needed. - **Safety:** The design and spacing of pillars are crucial for maintaining the stability of the underground workings and preventing collapses. Advantages of Bord and Pillar Mining: - Selective Extraction: Allows selective extraction of coal, leaving behind support pillars. - Safety: Provides good roof support, reducing the risk of roof collapses. Challenges: - Recovery Efficiency:Recovery rates may not be as high compared to some other mining methods, as significant portions of coal are left in pillars. - Pillar Stability: Pillar stability is critical to prevent subsidence and maintain safety. Variations: There are variations of the bord and pillar method, such as the "room and pillar" method, which involves larger rooms and pillars and is commonly used in metal mining. Bord and pillar mining is particularly suitable for relatively shallow, flat-lying coal seams and has been a traditional method for coal extraction in many mining regions around the world. Source : Karim El-behairy, LinkedIn