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Open-pit mining, also known as open-cast or open-cut mining and in larger contexts mega-mining, [1] is a surface mining technique that extracts rock or minerals from the earth. Open-pit mines are used when deposits of commercially useful ore or rocks are found near the surface where the overburden is relatively thin. In contrast, deeper mineral ...
Mine reclamation is the process of modifying land that has been mined to ecologically functional or economically usable state. Although the process of mine reclamation occurs once mining is completed, the planning of mine reclamation activities occurs prior to a mine being permitted or started. [1] Mine reclamation creates useful landscapes ...
Drilling and blasting. Drilling and blasting is the controlled use of explosives and other methods, such as gas pressure blasting pyrotechnics, to break rock for excavation. It is practiced most often in mining, quarrying and civil engineering such as dam, tunnel or road construction. The result of rock blasting is often known as a rock cut .
Concrete degradation may have many different causes. Concrete is mostly damaged by the corrosion of reinforcement bars due to the carbonatation of hardened cement paste or chloride attack under wet conditions. Chemical damage is caused by the formation of expansive products produced by chemical reactions (from carbonatation, chlorides, sulfates ...
Rust is a general name for a complex of oxides and hydroxides of iron, [4] which occur when iron or some alloys that contain iron are exposed to oxygen and moisture for a long period of time. Over time, the oxygen combines with the metal, forming new compounds collectively called rust, in a process called rusting.
A quarry is a type of open-pit mine in which dimension stone, rock, construction aggregate, riprap, sand, gravel, or slate is excavated from the ground. The operation of quarries is regulated in some jurisdictions to manage their safety risks and reduce their environmental impact. [1] [2]
The gel points of some common petroleum products are as follows: #1 diesel fuel: 15.5 °F (−9.2 °C). #2 diesel fuel: 17.5 °F (−8.1 °C). Heating oil: 16.0 °F (−8.9 °C). Kerosene: −40.0 °F (−40.0 °C). For the petroleum product to flow again, it needs to be brought above the gel point temperature to the ungel point, which is ...
While California waits for the EPA to act, more than 1,200 trucks have obtained new registrations to move cargo at the ports of Los Angeles and Long Beach this year; 90% run on diesel.