Mine Site Restoration and Fossil Fuel Energy Insights
Mine Site Restoration and Revegetation
Primary Goals of Revegetation
The primary goals of revegetation are restoration, erosion reduction, water resource protection, and landscape integration. Establishing a mulch cover in areas affected by mining aims to stabilize the ground immediately and prepare it for the planned conditioning systems.
Limiting Factors in Restoration
Key limiting factors are largely dependent on the revegetation system, the mine’s operating and rebuilding plan, the final resulting topography, and other variables. Limiting factors for plant establishment have been widely investigated in spoil heaps of different origins. Carbon mining substrates are among the most difficult to revegetate.
Processes for Abandoned Mines
The Revegetation Process
Revegetation, performed at an early stage and during the mine’s decommissioning phase, can restore the vegetation cover of the spoil heap. The stages are:
- The ground is prepared by adapting the slopes and hills.
- Grass seeds are sown.
- The growth of the species is monitored.
The Reforestation Process
Reforestation, following the initial revegetation, can restore rustic vegetation. Its purpose is to preserve wildlife habitat. The actions include:
- The slopes are properly graded and prepared.
- The area is seeded with native shrub species.
- Growth is monitored for several months.
Understanding Energy Resources
Non-Renewable Energy Resources
These are resources that, like minerals, do not regenerate or do so at an infinitely slower pace than their consumption. These materials, such as fossil fuels, often contain stored energy and are found in the earth in limited quantities.
Renewable Energy Resources
These are resources where regeneration occurs at a rate equal to or slightly less than their consumption. They consist of an endless flow of energy from constant earth processes or are materials with stored energy that regenerate rapidly, such as biomass.
A Closer Look at Fossil Fuels: Coal
What Are Fossil Fuels?
The main energy sources we currently use are substances formed from the transformation, within the Earth’s crust, of the remains of organisms that lived millions of years ago.
The Story of Coal
Coal is the most abundant fossil fuel and was the main energy source of the Industrial Revolution. Its importance is diminishing due to difficulties in extraction and distribution, as well as significant environmental problems.
How Coal is Formed
The most suitable period for coal formation occurred in the Carboniferous period. The stages of its formation are:
- An area with lush vegetation is located near the sea.
- The sea level rises, causing the vegetation to die and become covered by sediments.
- The plant remains do not fully decompose and are transformed into carbon within the sediment.
- The ground subsides, and the sea retreats. The carbon accumulates in the subsoil.
Exploiting Coal Deposits
Site Characteristics and Location
The sedimentary environment and tectonic processes influence the composition and thickness of coal layers, the depth of the deposit, and the type of associated sedimentary rock. These factors determine the ease and cost of undertaking the mining operation.
Coal Quality and Types
The quality of coal is mainly determined by the amount of stored energy, which depends on the degree of burial and the heat the reservoir endured during lithification. The best coals have endured greater pressures and temperatures. The main types of coal are:
- Anthracite (90-95% carbon)
- Bituminous coal (80% carbon)
- Lignite (brown coal) (70% carbon)
- Peat (45-60% carbon)