Area strip mining is a method of surface mining specifically designed to extract ore from large, flat terrains by systematically removing the overlying earth in long, parallel strips. This technique is characterized by its efficient handling of the overburden, the rocks and soil covering the valuable ore.
How Area Strip Mining Works
The process of area strip mining involves several key steps that distinguish it from other mining methods:
- Initial Cut: A long, narrow strip of overburden is removed to expose the underlying ore. This first cut creates a trench.
- Ore Extraction: The exposed ore is then mined and transported away.
- Overburden Backfilling: Crucially, the overburden from the next adjacent strip is strategically dropped into the previously mined strip. This continuous backfilling ensures that the land is progressively reclaimed and prevents the creation of long, open trenches or "gaps" in the earth after the mining is complete.
- Repetition: This process is repeated across the flat terrain, creating a series of parallel strips, with each new strip's overburden filling the one before it.
Key Characteristics of Area Strip Mining
To better understand area strip mining, here's a summary of its defining features:
Feature | Description |
---|---|
Terrain Type | Primarily conducted on large, relatively flat or gently rolling landscapes. It is not suited for mountainous or highly irregular topography. |
Methodology | Involves the excavation of material in long, sequential strips. |
Overburden Mgmt. | Overburden (rocks and soil) from a new strip is deposited directly into the previously mined strip, facilitating concurrent reclamation efforts. This contrasts with methods that pile overburden externally. |
Environmental Impact | While still a form of surface mining, the backfilling process aims to mitigate the visual impact and aid in land restoration by avoiding permanent, extensive open pits. Subsequent efforts often include re-grading and revegetation. |
Target Ores | Commonly used for extracting widespread, relatively shallow deposits of minerals such as coal, phosphate, and certain types of bauxite. |
Area Strip Mining vs. Contour Mining
It's important to distinguish area strip mining from contour mining, another form of strip mining. While both are surface mining techniques, they are employed in different geographical settings:
- Area Strip Mining: Ideal for flat, expansive areas, moving across the landscape in straight or slightly curved lines.
- Contour Mining: Specifically adapted for hilly or mountainous terrains. It follows the contours of an ore outcrop along the side of a hill, removing overburden and ore in a "bench" cut into the hillside.
Understanding these distinctions highlights how different mining methods are chosen based on the unique geological and topographical characteristics of a site. For more information on various surface mining techniques, you can refer to resources on Strip Mining.