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Common levelling instruments include the spirit level, the dumpy level, the digital level, and the laser level. Levelling staff – specialized measuring stick or vertical staff used with the dumpy level, held by a second person while the operator of the level looks through it and takes readings off of the staff. Also call a rod.
Surface gold mine with haul truck in foreground, in Kalgoorlie, Australia. Mining in the engineering discipline is the extraction of minerals from the ground. Mining engineering is associated with many other disciplines, such as mineral processing, exploration, excavation, geology, metallurgy, geotechnical engineering and surveying.
Mining of sulfur from a deposit at the edge of Ijen's crater lake, Indonesia. Mining is the extraction of valuable geological materials and minerals from the surface of the Earth. Mining is required to obtain most materials that cannot be grown through agricultural processes, or feasibly created artificially in a laboratory or factory.
There are two principal phases of underground mining: development mining and production mining. Development mining is composed of excavation almost entirely in (non-valuable) waste rock in order to gain access to the orebody. There are six steps in development mining: remove previously blasted material (muck out round), scaling (removing any unstable slabs of rock hanging from the roof and ...
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 ...
How smiths learned to produce copper/tin bronzes is unknown. The first such bronzes may have been a lucky accident from tin-contaminated copper ores. However, by 2000 BC, people were mining tin on purpose to produce bronze—which is remarkable as tin is a semi-rare metal, and even a rich cassiterite ore only has 5% tin. [citation needed]
Payhauler 350; Overview; Manufacturer: International Harvester Payhauler Corp. Terex Corp. Production: 1956-1982 (IHC) 1982-1998 (Payhauler) 1998-2003 (Terex)