Mining/tunneling

Safety issues are not covered here. These are dealt with in Systems and Equipment book, and some fundamental issues will be taken up in the second edition of the Fundamentals book. The following aspects should be taken into account in system design fan safety AHU fire protection issues safety measures in mines, tunnels, underground car parks, etc. transportation of chemical and explosives. 

Di-/ -octylphthalatc was detected in 4% of the urban runoff samples collected from a total of 15 cities. Di-ra-octylphthalate was detected at three cities at concentrations of 0.4-1 pg/L (Cole et al. 1984). The compound was found in water samples collected at four locations along the entire length of the Mississippi River at concentrations of 24-310 ng/L (DeLeon et al. 1986). At the Butler Mine Tunnel NPL Site located in Pittston, Pennsylvania, di-n-octylphthalate was detected in on-site oil/groundwater samples at concentrations of 110-792,000 ppb (ATSDR 1989b). Di-n-octylphthalate was detected at a concentration of 1 ppb in a water sample collected from the discharge pond of a phthalate ester plant located on the Chester River in Maryland (Peterson and Freeman 1984). Di-n-octylphthalate was found at 0.001-0.02 ppm in water samples taken from a river that received industrial waste water from a specialty chemical manufacturing plant (Jungclaus et al. 1978). 

ATSDR. 1989b. Health assessment for Butler Mine Tunnel, Pittson, Pennsylvania. Agency for Toxic Substances and Disease Registry, Atlanta, GA. PB90-143603. 

It is interesting to note that stratified combustible gas mixtures can exist in tunnel-like conditions. The condition in a coal mine tunnel is an excellent example. The marsh gas (methane) is lighter than air and accumulates at the ceiling. Thus a stratified air-methane mixture exists. Experiments have shown that under the conditions described the flame propagation rate is very much faster than the stoichiometric laminar flame speed. In laboratory experiments simulating the mine-like conditions the actual rates were found to be affected by the laboratory simulated tunnel length and depth. In effect, the expansion of the reaction products of these type laboratory experiments drives the flame front developed. The overall effect is similar in context to the soap bubble type flame experiments discussed in Section C5c. In the soap bubble flame experiment measurements, the ambient condition is about 300 K and the stoichiometric flame temperature of the flame products for most hydrocarbon fuels... 

A series of articles (Refs 23, 24 27) describe the application of shaped charges in various branches of commercial blasting, such as mining, tunneling, oil well blasting, etc... 

Uses. In section 1, we showed that most of the LOX in the USA are used in the strip mining of coal. In Europe LOX were also extensively used in open pit mining, tunneling and construction. Indeed, in the first half of this century, LOX were used in most expls applications, although not extensively, where fumes were not a problem. O Neil Van Fleet (Ref 5a) consider LOX economical and safe (See Sect 4 on LOX safety). La Magna (Ref 9) prefers LOX to Dynamites. In the last decade... 

A graphite mine tunnel has a 3- x 3-m cross-section. How thick must a layer of graphite dust on the floor he to give an explosive concentration of 40 g/m3 when 15 percent of it is resuspended Assume the bulk density of the graphite dust layer is 1.4 g/cm3. 

Damage Youngest larvae mine tunnels in leaves of cabbage family plants and weeds. 

When a horizontal opening is created in a solid or fissured rock formation, tensile stresses are generated in the roofs of these openings. In a solid formation, the opening may remain stable for various lengths of time. In a fissured formation, or even in a solid formation of weak rock, the opening may cave immediately, or in a short period of time. Rock bolts are widely used in mine tunnels drifts) as a major means of roof support. 

There are, however, several important niche applications for CAC. Most notably, CACs are used as linings to sewers and mine tunnels. Calcium aluminate cements are resistant to chemical attack from sulfate-producing bacteria that thrive in sewer systems (especially in warmer climates), and sprayed concrete linings to sewers have been shown to resist degradation for periods up to 30 years. The high impact and abrasion resistance of CAC also makes it suitable as a lining material for ore tunnels in mines and because CAC sets rapidly, it can be sprayed onto tunnel walls (as shotcrete ) and even used as a tunnel lining. 

RokLtdc . P lexible Rods.] Folyure-tiiane bindm for contred of water and brtdcen strata in mines, tunnels, shafts, and stream sealing tq>plics. 

Truck shop 2.32 Mine tunnel 12.3 S15PAH, winter Bus depot 24.6 ... 

For centuries, engineering meant just two things military engineering was concerned with fortifications and other structures for warfare civil engineering included roads, bridges, waterways, mines, tunnels, and other nonmihtary structures. Other fields of engineering are modem inventions. The first engineering school in the United States, West... 

The metal concentrations of the water were mostly below the detection limit (data are not presented). From the metal concentrations of the moss it is evident that the sampling sites at the river Selke are more contaminated than those of the other sites. The sites Selke 1 and Selke 2 are upstream of the village Alexisbad, whereas the site Selke 3 is downstream from this settlement. Waste from disused mining tunnels is dumped into the Selke as it passes the village. Moss from the Wipper contained significantly less metals. This sampling site lies in an area without settlement and surrounded by meadows. The interpretation of the data from the other streams is difficult. The accumulation by mosses is influenced by various parameters and metal concentrations of the water can not be calculated from the concentrations of the moss. The presence of competing ions like Ca (Wells and Brown, 1987, 1990), the pH values and the amount of suspended matter may affect the quantity of free metal ions and the enrichment by the moss. 

Underground gold mines puncture ore bodies with adits, mine tunnels, and shafts that allow air and water to enter and react with sulfide materials that are exposed inside the mine. AMD can leach from underground mine openings into streams and aquifers. In open pit mines, sulfide minerals on the exposed sides of the pit excavation are moistened by... 

Sun Jiping, Li Jisheng Lei Shuying. 2005. Choice of optimal frequency for radiao communication in mine tunnel. Journal of Uaoning Technical University 24(3) 378-380. 

The research of dynamometer for anchor cable in mine tunnel based on the industrial Ethernet... 

Milne D, Hadjigeorgiou J Pakalnis R. 1998. Rock mass characterization for tmderground hard rock mines. Tunnelling and Underground Space Technology (13) 383 391. 

However, mine tailing dumps produce acid mine drainage that can seep into waterways and aquifers, with serious consequences for ecosystems. If underground mine tunnels collapse, this can cause subsidence of land surfaces. During actual mining operations, methane may be released into the air thereby contributing to the greenhouse effect. 

Some controlled explosions are very useful. For example, explosions occur inside cylinders of internal combustion engines. Blasting materials are common to certain mining, tunneling, and quarrying activities. 

Comment piezoelectric meters deliver signals and have a medium price range. They are capable of measuring from 0.1 to nearly 1,000 bar. Therefore, one of its applications is to detect landslides in mine tunnels. 

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