Search results
Results from the WOW.Com Content Network
The ore deposit type is Polymetallic veins of hydrothermal origin. The mining method used is underhand cut and fill mining. [3] The mine's primary access and production are through the Silver Shaft, an 18-foot (5.5 m) diameter, concrete-lined shaft sunk to a depth of 6,200 feet (1,890 m), [4] [5] [6] over 2,800 feet (855 m) below sea level.
Cut and fill mining is a method of short-hole mining used in steeply dipping or irregular ore zones, in particular where the hanging wall limits the use of long-hole methods. The ore is mined in horizontal or slightly inclined slices, and then filled with waste rock, sand or tailings. Either fill option may be cemented with binders to add ...
In shrinkage stoping, mining proceeds from the bottom upwards, in horizontal slices (similar to cut and fill mining), with the broken ore being left in place for miners to work from. Because blasted rock takes up a greater volume than in situ rock (due to swell factor ), some of the blasted ore (approximately 40%) must be removed to provide ...
Room and pillar mining was one of the earliest methods used, [3] although with significantly more manpower. The room and pillar system is used in mining coal , gypsum , [ 4 ] iron , [ 5 ] limestone , [ 6 ] and uranium [ 7 ] ores, particularly when found as manto or blanket deposits, stone and aggregates , talc , soda ash , and potash . [ 8 ]
Find theme words to fill the board. Theme words stay highlighted in blue when found. Drag or tap letters to create words. If tapping, double tap the last letter to submit.
No. 1 Oregon (13-0) is the only undefeated team in college football and opens as the favorite for the title at +325. However, there are three other teams with odds of +450 or better. And two of ...
Drift mining is either the mining of an ore deposit by underground methods, or the working of coal seams accessed by adits driven into the surface outcrop of the coal bed. [1] A drift mine is an underground mine in which the entry or access is above water level and generally on the slope of a hill, driven horizontally into the ore seam. [2]
The current average interest rate for a 30-year fixed mortgage is 6.80% for purchase and 6.80% for refinance — up 7 basis points from 6.73% for purchase and 5 basis points from 6.75% for ...