1992-10-20_REVISION - M1977348 ‎(4)‎

• Permit No: M1977348
• IBM Index Class Name: Revision
• Doc Date: 10/20/1992
• Doc Name: APPLICATION FOR AMENDMENT MLR 77-348
• From: Holnam
• To: DMG
• Type & Sequence: AM1
• Media Type: D
• Archive: No

• EXHIBIT D - FOR AMENDMENT 10/20/92
MINING PLAN
Introduction:
Holnam Inc operates the cement plant, formerly owned by Ideal
Basic Industries, Inc., located two miles north of Laporte,
in Larimer County, Colorado. The Boettcher limestone quarry
supplies the principal raw material for the plant. This
quarry is a complex operation producing from several band
within the Niobrara formation (see Typical Cross Section).
The raw feed for the cement plant is a blend of the vario»s
bands yielding the chemical balance needed for cement
production. The proportions for the blend changes with e+3ch
type of cement produced, and actually changes from hour to
hour according to the chemical needs as determined by
constant sampling. On any given day, material from as many
as five locations in the quarry may be delivered to the
crusher for use in the raw mix.
With the pattern of quarry operation so complex, this minting
plan must, of necessity, be simplified. The E-1, E-2, anti E-
3 bands have been treated as a single band. Weathered
material is treated as part of its parent band, even thou<ih
it is normally produced well ahead of the quarrying operation
on that parent band. The quarry has been divided into 16
areas for the purposes of this plan. Each area is a discrete
unit in the operation. Each area is identified by a letter
according to which band in the formation it contains, and a
number in sequence from south to north. Each area is treeited
as a single face, although, in fact, any given point may
remain in the active mining area for 5 years or more. This
is necessitated by time required for the stripping sequence,
machine downtime cushion, and minimum required operating
distances between quarry faces (see Boettcher Quarry
Sequence).
Basic Assumptions
To arrive at a sequence and time table for such a complex and
long range plan, certain assumptions must be made, even
though some of them will be changed during the course of t:he
operation.
The assumptions which have been followed are:
1. The rate of production has been calculated according
to the design capacity of this plant, that is,
950,000 tons of clinker per year. This plant is the
third plant built during the 65-year history of this
operation, so it is probable that it will be
replaced at least twice before the end of the
operation. Each new plant will probably have a
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