Deep mining

Total 1991 world production of sulfur in all forms was 55.6 x 10 t. The largest proportion of this production (41.7%) was obtained by removal of sulfur compounds from petroleum and natural gas (see Sulfurremoval and recovery). Deep mining of elemental sulfur deposits by the Frasch hot water process accounted for 16.9% of world production mining of elemental deposits by other methods accounted for 5.0%. Sulfur was also produced by roasting iron pyrites (17.6%) and as a by-product of the smelting of nonferrous ores (14.0%). The remaining 4.8% was produced from unspecified sources. 

Figure 4. Comparison of GHG emissions from shale gas and conventional natural gas with low and high estimates of fugitive methane emissions, surface-mined coal, deep-mined coal, and diesel oil time horizon equal to 100 years [27]...

It follows also that the actual rate of burning of safety fuse depends on the ambient pressure. Indeed, if the pressure is reduced to less than about a fifth of an atmosphere the burning ceases altogether. In deep mines the extra pressure can be sufficient to give an increase in burning speed of safety fuse. Compared with the effect of pressure other influences on the burning speed are small. Temperature has little effect and humidity also has little effect unless the fuse is kept for a prolonged period at a humidity sufficient to cause deliquescence of the potassium nitrate in the core. 

The amount of solid waste depends on the method of uranium ore exploration. By deep mining, each ton of ore is supplemented by 0.2-0.3 tons of waste ores, and by open pit mining, per 1 ton of ore up to 8-10 tons of excavation materials are produced. Moreover, uranium ores contain from 5% up to 25-30% of waste ores, which are deposited as mine tails. 

Deep mines averaging 1000 ft are used to take the solid material directly from the deposit. Salt obtained by this method is 98.5-99.4% pure. Leading states producing rock salt and their percentages are Louisiana (30%), Texas (21%), Ohio (13%), New York (13%), and Michigan (10%). Over one fourth of the world s salt is produced in the U.S. 

Colliery Culm bank Deep mine Diming Coal mine, especially an underground mine for coal See spoil heap See underground mine Excavation of tloor strata below a thin coal seam to improve the overall working height of roadways, thus improving access (see also ripping)... 

Drill mine Dusl explosion Deep mine in wrhieh the workings arc principally accessed by an adit Accidental explosion in an underground mine due to the explosive ignition of line particles of coal suspended in the mine atmosphere... 

Although the challenges and methodologies are essentially the same in both cases, the term reclamation is typically applied to applications concerning spoil heaps formed by deep mining operations, whereas restoration is the preferred... 

Adams, R. Younger, P. L. 2001. A strategy for modeling ground water rebound in abandoned deep mine systems. Ground Water, 39, 249-261. 

Younger, P. L. 2000. Predicting temporal changes in total iron concentrations in groundwaters flowing from abandoned deep mines a first approximation. Journal of Contaminant Hydrology, 44, 47-69. 

It thus appears, that under a diminished pressure water seethes at a lower temperature, and theeame happens with other liquids. Saussure found that, on the top of Mont Blanc, water boiled at 184° Fahr, In deep mines, on the contrary, It requires a muoh higher temperature than 212° to bring it to a state of ebullition. On this circum stance lias been based the con-... 

Another form of underground mining is known as conventional mining. Tliis process accounts for about 11% of deep-mined coal and consists of a series of operations that involve cutting the coalbed so that it breaks easily when blasted with explosives. The broken coal then is ready to be removed from Ihe mine. Where the geology is favorable, this is the most practical and economical underground mining method. 

Rock salt is produced from deep mines so that the salt is taken directly from the deposit. Salt obtained by this method is 98.5 to 99.4% pure. 

Neutrinos (name given by Fermi) carry little mass, occur with great abundance in the universe, but are very difficult to detect, because they often pass through the mass of the earth without deflection or detection. Huge tanks of liquid chlorinated hydrocarbons in deep mines have been successfully tested for neutrino-induced formation of a few atoms of radioactive argon. 

Uranium mines are primarily the open pit type, but there is significant production from deep mines as well as from solution mining. Sometimes uranium is produced as a byproduct of mining operations for vanadium, phosphate, and gold. 

In 1989 a deep mined repository, The Waste Isolation Pilot Plant, was opened in a bedded salt formation near Carlsbad, New Mexico. The site has been receiving transuranic wastes since and has now disposed hundreds of tons. 

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