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F~ ~ III IIIIIIIIIIIIIIII <br />HOLNAM INC, FORT COLLINS PLANT, BOETTCHER QUARRY, PERMIT NO,P371 ~¢$9( <br />Introduction: Mined Lallnyd <br />The Boettcher limestone quarry supplies the principal k•'~[w"l~a~f~lni~I''` <br />for the Fort Collins cement plant. This quarry is a complex <br />operation producing from several bands within the Niobrara <br />formation. The raw feed for the cement plant is a blend of the <br />various bands yielding the chemical balance needed for cement <br />production. The proportions for the blend changes with each type <br />of cement produced, and indeed changes from hour to hour according <br />to the chemical needs as determined by constant samplinf;. On any <br />given day material from as many as five locations in the ~~uarry may <br />be delivered to the crusher for use in the raw mix. <br />With the pattern of quarry operation so complex, this m:~ning plan <br />must of necessity be simplified. The E-1, E-2, and E-3 hands have <br />been treated as a single band. Weathered material is treated as <br />part of its parent band, even though it is normally produced well <br />ahead of the quarrying operation on the parent bawd. 7'he quarry <br />has been divided into 16 areas for the purposes of this p=ian. Each <br />area is a discrete unit in the operation. Each area is identified <br />by a letter according to which band in the formation that it <br />contains, and a number in sequence from south to north. Each area <br />is treated as a single face, although in fact any given point may <br />remain in the active mining area for 4.5 years or more. This is <br />necessitated by time required for the stripping sequence, machine <br />• downtime cushion, and minimum required operating distances between <br />quarry faces. <br />BASIC ASSUPIPTIONS <br />To arrive at a sequence and time table for such a complex: and long <br />range plan, certain assumptions must be made, even though some will <br />be changed during the course of the operation. <br />The following assumptions have been made: <br />1. The rate of production has been calculated according to the <br />design capacity of this plant, that is, 450,000 tons of clinker per <br />year. This plant is the third plant built during th~~ 65-year <br />history of this operation, so it is probable that it will be <br />replaced at least twice before the end of the operation. Each new <br />plant will probably have a higher capacity. <br />2. Under present mix specifications this production rate <br />results in a quarrying rate of approximately 305,000 cubic: yards of <br />material from this quarry per year. <br />3. Waste kiln dust (CKD) volume will remain constant at <br />approximately 117,000 cubic yards per year. Process refinements <br />may change this rate of production. <br />4. All CKD will be landfilled in the quarry. In actuality, <br />