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<br />etructing a bulkhead in the Time mine, and pumping the water from Left Hand <br />Creek behind this bulkhead, both the Time and Wynona mines are being used <br />for the underground storage of water for m~ purposes. Together, these two <br />mines have sufficient capacity to afore enough water to carry the milling <br />operation through the period between November 1 and May 31. Mill water is <br />being drawn from these mine workings by pumping water out of the Wynona <br />mine shaft. <br />C.O.M. Inc.'s concentration mill is housed in a metal building 70 feet wide, 120 <br />feet long, and 30 feet high, with three separate working levels. A metal frame <br />building was constructed on a concrete foundation with an upper elevation of <br />8,590 feet, an intermediate elevation of 8,595 feet, and a lower elevation of <br />8,575 feet (see Map A). The upper terrace supports the crushing plant and the <br />grinding circuit, the middle terrace contains the gravity concentration circuit, <br />and the lower terrace encloses the flotation concentration circuit. Con~truc- <br />tion of these three levels, and the two retaining walla that separate the middle <br />level, required some excavation of the underlying granite, and inwlved cut and <br />fill grading. Excavstion of the site, snd construction of the retaining and <br />foundation walls, was followed by the installation of the heavy crushing and <br />nulling equipment. Special reference waa given to the support of the heavy or <br />vibrating machinery that was used in the milling process, and eubetantial, <br />separate foundations were included in the mill building's design. The erection of <br />the steel frame, and the attachment of the metal wall and roof panels, pro- <br />ceeded along with the necessary plumbing and electrical work. An internal <br />wall, insulated on both sides to reduce noise and dust, separates the crushing <br />plant from the grinding circuit on the upper level of the mill. Three coarse ore <br />bins, one fine ore bin, and a thickener tank were fabricated from etQel at the <br />millsite. The total amount of the surface acreage affected by the construction <br />of this building, the three coarse ore bins, and the associated receiving and <br />shipping arnaa of the milling facility is 0.389 acres. <br />A 30 by 40 foot metal building is planned to house an assay laboratory and mill <br />office was built following the completion of the millsite. This building was con- <br />structed southwest of the millsite, on the patented Oscar Lode, between the <br />8.590 and 8.595 foot contour interval i see Map Ai. The total affected land sur- <br />face that was involved in the construction of this building waa 0.027 acres. <br />If any other structures or buildings are found to be necessary for the safe or <br />efficient operation of this milling complex, they will be built in the area encom- <br />paseed by the boundaries of this permit application. All of the atauctiu~es will <br />have the same color of metal siding, and will be built in accordance with <br />Boulder Count}~s building codes and regulations. <br />Because the mill processes both gold-silver tellurides and various combinations <br />ofgold-silver sulfides, it was designed as a composite system of gravity and <br />flotation concentration. The ore processing flow chart shows diagrammatically <br />the sequence of operations that take place in the plant (see FYgure 1). It is a <br />simplified version of the flow sheet that was used to design this concentration <br />mill. The flow sheet was developed to decide the number, types, sizes, and <br />