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Underground soft-rock mining is a group of underground mining techniques used to extract coal, oil shale, potash, and other minerals or geological materials from sedimentary ("soft") rocks. [1] Because deposits in sedimentary rocks are commonly layered and relatively less hard , the mining methods used differ from those used to mine deposits in ...
In a fossil fuel power plant the chemical energy stored in fossil fuels such as coal, fuel oil, natural gas or oil shale and oxygen of the air is converted successively into thermal energy, mechanical energy and, finally, electrical energy. Each fossil fuel power plant is a complex, custom-designed system.
Shale is characterized by its tendency to split into thin layers less than one centimeter in thickness. This property is called fissility. [1] Shale is the most common sedimentary rock. [2] The term shale is sometimes applied more broadly, as essentially a synonym for mudrock, rather than in the narrower sense of clay-rich fissile mudrock. [3]
Electrical heating elements are lowered into the heating wells and used to heat oil shale to between 650 °F (340 °C) and 700 °F (370 °C) over a period of approximately four years. [2] [6] Kerogen in oil shale is slowly converted into shale oil and gases, which then flow to the surface through recovery wells. [4] [6]
[45] [46] In 2002, about 97% of air pollution, 86% of total waste and 23% of water pollution in Estonia came from the power industry, which uses oil shale as the main resource for its power production. [47] Oil-shale extraction can damage the biological and recreational value of land and the ecosystem in the mining area.
An auxiliary ventilation system takes air from the flow-through system and distributes it to the mine workings via temporarily mounted ventilation fans, Venturi tubes and disposable fabric or steel ducting. Auxiliary fan and duct systems may be either forcing systems, where fresh air is pushed into mine headings, or exhausting systems that draw ...
Oil shale mining reduces the original ecosystem diversity with habitats supporting a variety of plants and animals. After mining the land has to be reclaimed, process takes time and cannot necessarily re-establish the original biodiversity. [3] [4] The impact of sub-surface mining on the surroundings will be less than for open pit mines ...
Oil shale is an organic-rich fine-grained sedimentary rock containing kerogen (a solid mixture of organic chemical compounds) from which liquid hydrocarbons can be produced. In addition to kerogen, general composition of oil shales constitutes inorganic substance and bitumens.