Room and pillar mining

Room and pillar or pillar and stall is a variant of breast stoping. It is a mining system in which the mined material is extracted across a horizontal plane, creating horizontal arrays of rooms and pillars. To do this, "rooms" of ore are dug out while "pillars" of untouched material are left to support the roof – overburden. Calculating the size, shape, and position of pillars is a complicated procedure, and an area of active research.[1] The technique is usually used for relatively flat-lying deposits, such as those that follow a particular stratum. Room and pillar mining can be advantageous because it reduces the risk of surface subsidence compared to other underground mining techniques.[2] It is also advantageous because it can be mechanized, and is relatively simple. However, because significant portions of ore may have to be left behind, recovery and profits can be low.[1] Room and pillar mining was one of the earliest methods used,[3] although with significantly more manpower.

The room and pillar system is used in mining coal, gypsum,[4] iron,[5] limestone,[6] and uranium[7] ores, particularly when found as manto or blanket deposits, stone and aggregates, talc, soda ash, and potash.[8] It has been used worldwide from the Czech Republic[2] to China[9] to the US.[4]

  1. ^ a b Kim, Jong-Gwan; Ali, Mahrous A. M.; Yang, Hyung-Sik (2018-10-27). "Robust Design of Pillar Arrangement for Safe Room-and-Pillar Mining Method". Geotechnical and Geological Engineering. 37 (3): 1931–1942. doi:10.1007/s10706-018-0734-1. ISSN 1573-1529.
  2. ^ a b Hudeček, V.; Šancer, J.; Zubíček, V.; Golasowski, J. (January 2017). "Experience in the Adoption of Room & Pillar Mining Method in the Company OKD, a.s., Czech Republic". Journal of Mining Science. 53 (1): 99–108. doi:10.1134/s1062739117011908. hdl:10084/124488. ISSN 1062-7391.
  3. ^ Croyle, Floyd D.; Kohler, Jeffrey L.; Bise, Christopher J. (November 1987). "Maximum Demand and Demand Factors in Underground Coal Mining". IEEE Transactions on Industry Applications. IA-23 (6): 1105–1111. doi:10.1109/tia.1987.4505039. ISSN 0093-9994.
  4. ^ a b Marshall, Lawrence G. (1959). Mining methods and costs, Iowa Gypsum deposits. Bureau of Mines. OCLC 680481821.
  5. ^ Grgic, Dragan; Homand, Francoise; Hoxha, Dashnor (October 2003). "A short- and long-term rheological model to understand the collapses of iron mines in Lorraine, France". Computers and Geotechnics. 30 (7): 557–570. doi:10.1016/S0266-352X(03)00074-0.
  6. ^ Pillar and Roof Span Design in Stone Mines, CDC
  7. ^ Paul, Michael, et al. "Mine flooding and water management at underground uranium mines two decades after decommissioning." Proc. IMWA Conference. 2013.
  8. ^ Hamrin, Hans (1986). Guide to underground mining methods and applications. Stockholm, Sweden: Atlas Copco.
  9. ^ Zhou, Nan; Li, Meng; Zhang, Jixiong; Gao, Rui (2016-11-29). "Roadway backfill method to prevent geohazards induced by room and pillar mining: a case study in Changxing coal mine, China". Natural Hazards and Earth System Sciences. 16 (12): 2473–2484. doi:10.5194/nhess-16-2473-2016. ISSN 1684-9981.