1,128
edits
Changes
Jump to navigation
Jump to search
Line 7:
Line 7: + + +
+
Sub-surface mining is called hard rock mining if the mining is for hard minerals such as precious metals, and soft rock mining if it is for soft minerals such as coal. Underground mines are also categorized by the direction of entry underground. A drift mine enters the earth horizontally, a slope mine enters the earth at a downward slope, and a shaft mine uses a vertical or steeply inclined downward shaft to enter the mine.
Sub-surface mining is called hard rock mining if the mining is for hard minerals such as precious metals, and soft rock mining if it is for soft minerals such as coal. Underground mines are also categorized by the direction of entry underground. A drift mine enters the earth horizontally, a slope mine enters the earth at a downward slope, and a shaft mine uses a vertical or steeply inclined downward shaft to enter the mine.
==Safety==
Dangerous gases such as [[methane]] can accumulate in mines and can explode if ignited, and the inhalation of dusts is also a health issue, so underground mines must be ventilated, typically with large fans located above ground which keep air circulating through the mine.
[[Category:Geology]]
[[Category:Geology]]