Longwall Mining

{
  "id": "MLC-T-ENV-016046",
  "term": "Longwall Mining",
  "field": "Environment",
  "definition": "In level, tabular ore bodies it is possible to recover virtually all of the ore by using this method (in the United States, only coal is known to have been mined using longwall methods). Initially, parallel drifts are driven to the farthest boundary of the mine area. The ore between each pair of drifts is then mined along a continuous face (the longwall) connecting the two drifts. Mining proceeds back toward the shaft or entry, and only enough space for mining activities is held open by moveable steel supports. As the longwall moves, the supports are moved with it and the mined out area is allowed to collapse. Various methods can be used to break up and remove the ore. In many cases, the rock stresses that are caused by the caving of the unsupported area aids in breaking the material in the longwall face.",
  "references": [
    "EPA Abandoned Mite Site Characterization and Cleanup Handbook; Appendix A: Acronym List and Glossary of Mining Terms at http://www.epa.gov/superfund/policy/remedy/pdfs/appendix.pdf"
  ],
  "url": "https://mlchart.com/terminology/environment/longwall-mining/"
}