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Shaft mining or shaft sinking is the action of excavating a mine shaft from the top down, where there is initially no access to the bottom. [1] Shallow shafts , typically sunk for civil engineering projects, differ greatly in execution method from deep shafts, typically sunk for mining projects.
Shaft sinking was the most dangerous and most difficult form of mining in ancient Rome. Due to its high cost, it was only used to collect the most valuable metals in Roman society. This technique involved digging tunnels underground, allowing workers to extract the ore.
The company considered sinking another well (the Saint-Joseph well, which would be sunk the following year), but sinking a well can take five to six years, and the company needed immediate resources. It therefore decided to sink an inclined plane at the same time as the Saint-Joseph shaft, to reach the area to be mined more quickly.
The sinking of the shaft began on May 26, 1863. [2] By 1868, the shaft had reached a depth of 447 meters, and the engineers realized that the inclination of the geological strata had changed. While the engineers thought they'd find coal at a depth of 530 meters, they still didn't reach it at 600 meters. [3]
When wet sinking a shaft the shaft is allowed to flood and the muck is excavated out of the base of the shaft underwater using a grab on the end of a crane or similar excavation method. Because the shaft is flooded, the lining can not be constructed at the excavation level of the shaft so this method only suits methods where the lining is ...
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 ...
More than 800 people have lost their lives in jail since July 13, 2015 but few details are publicly released. Huffington Post is compiling a database of every person who died until July 13, 2016 to shed light on how they passed.
These discoveries led to many mining operations and after shaft sinking for about 5 years (1981) Mponeng officially began mining operations in 1986. [10] [2] Before Mponeng, the mine was known as the Western Deep Levels South Shaft or the No1 Shaft; the name Mponeng came into use in 1999. [10]