PERMFILE47848 - Laserfiche WebLink

Home Browse Search

northern and upper portions of Tract A. • Tract A-1 - No mining will occur in this tract. It will serve primarily as an area for support facilities and buffer zone. Some future water control measures may be built here, but at this time no definite plans exist, because future operations will determine need. MINING METHOD - Extraction of limestone from this quarry is basically by the same method that was used at the Queen's Canyon Quarry. An area selected for extraction is first drilled with about 30 holes. The holes are filled with ammonium nitrate and detonated. This breaks the limestone in a block that from 20 to 30 feet thick over an area of several hundred to a few thousand square feet. Usually three such thicknesses are removed, but in some cases where the limestone is deeper more thicknesses would be taken. • After the rock has been blasted a caterpillar is brought in to move the rock to a pile where a front-end loader is used to load trucks for transporting the material to the processing facilities. In the process of moving the rock for loading some of the limestone is pulverized into fine material that can be used as a plant growth medium. The pulverization only occurs to a depth of about 6" so other procedures described in the reclamation plan must be used to produce a deeper medium. The removal of limestone, however, often does not occur in a sequential fashion as is the case with overburden removal at most coal strip mines. Market and demand changes as well as safety considerations often requires the drilling operation to move to another portion of the mine area. In this way, often two or more areas at rather widely spaced locations may be worked at any one time with drilling of the next block . occurir.g at one area while rock removal is occurrinq at another area. At other times, the two steps may occur next to each other. For this reason, P-D-3