Hard-rock mining

{
  "id": "MLC-T-ENV-012851",
  "term": "Hard-rock mining",
  "field": "Environment",
  "term_source": "Hard-Rock Mining",
  "definition": "1. Traditional hardrock mining usually involves digging tunnels and adits (horizontal entrances into hillsides) to reach lodes of mineral-rich ore. Traditional underground mining and open pit mining require that the ore-bearing rock be removed and then put through a milling and extraction plant to extract the desired minerals. After the ore body is exhausted, miners move on leaving behind huge mounds of finely-ground tailings and coarser waste rock, as well as an underground tunnel complex and/or open pit.\n\n2. Mining typically extracting metallic ores such as iron or copper",
  "subject": "Biological substances",
  "references": [
    "National Pollutant Discharge Elimination System (NPDES) Glossary",
    "EPA Mining at http://water.epa.gov/polwaste/npdes/Mining.cfm"
  ],
  "url": "https://mlchart.com/terminology/environment/hard-rock-mining/"
}