Types of Mining and Fracking
By: Ena Hodzic
Soil and rock laying on top of the mineral deposit are removed. There are three basic types of surface mining: open pit mining, strip mining, and quarry mining. Surface mining can be an inexpensive and safe method of reaching much needed resources. It also involves scraping away earth and rocks to get to the coal buried beneath the surface. In many cases, mountains are literally blasted apart to reach thin coal seams within, leaving permanent scars on the landscape as a result.
Strip mining at Garzweiler, Germany.
Sub-surface mining consists of digging tunnels or shafts into the earth to reach buried ore deposits. This form of mining is most commonly used for zinc, lead, nickel, tin, gold, diamonds, copper, phosphate, salt, coal and uranium. The three types are- Quarrying, solution mining, and longwall mining. There is an acid drainage from the equipment. The toxic water ends up in groundwater. Abandoned mining sites can continue polluting groundwater after the mining has ceased.
Difference between surface and subsurface?
Surface mining is used where the ore or material to be extracted is located close to the surface. The overlying ground cover is removed, the material is mined, and the ground cover is usually replaced. Subsurface mining is used where the material is in veins deep beneath the surface, or obstructed (by rock layers, water tables, or other strata) in a way that make surface access unsuitable. Early mines used existing caves, but technology has brought increasingly deep and complex drilling to reach veins of coal or metal ores.
The process of extracting natural gas from shale rock layers deep within the earth. Fracking makes it possible to produce natural gas extraction in shale plays that were once unreachable with conventional technologies. Water, sand and chemicals are injected into the rock at high pressure which allows gas to flow out of the head of the well. The process literally involves the smashing of rock with millions of gallons of water-along with sand and a undisclosed assortment of chemicals in order to bring gas to the surface.