Search results
Results from the WOW.Com Content Network
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.
The drilling of the shafts began in October 1783. 72 miners were involved in the work. After 9 months of intensive work, on July 16, 1784, rich lead and silver ore deposit was found at a depth of 18 m in "Rudolfina" shaft. Two days later a similar discovery was made in the shafts "Łyszczonek" and "Opal".
To achieve the first goal, five steam pumps with a total capacity of 79.29 m 3 /min were used – three drainage machines at the drainage shafts: Schmidt I [75] [76] (sinking began in 1855, [74] drainage machine put into use in 1858, [77] in 1859 riveted pipes made of 9.5-millimetre (3 ⁄ 8 in) thick boiler plate with a diameter of 910 ...
The above-day expansion of the shaft did not take place until 1949, when the shaft received a double-headed headframe. A breakthrough to the Ewald 3/4 mine followed. In 1969 the mine became the RAG Aktiongesellschaft and united with the Recklinghausen colliery. A mine gas extraction system was operated on shaft system 3/4
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 ...
A review that considered berberine’s effects on heart health found some studies supporting this claim, but due to the high risk of bias, the researchers recommended more clinical trials be ...
The fire pits that require users to pour isopropyl rubbing alcohol or another liquid fuel into an open container and then ignite at the same spot are considered "extremely dangerous," according to ...
Now, there’s a development in the story: As the National Post reports, the researchers made a miscalculation when crunching the data, suggesting that the findings aren’t as bad as they ...