Marble - Colorado Geological Survey

Production Calculations
Cubic Feet
Assume 6,000 cf from open quarry 1st month; 30,000 cf all additional months
Underground quarry develped during 1990, production starts in 1991 at 1000 cf/mo,
4000 cf/mo in 1992
1990 1991 1992 and after
4 months
Open
UG
Total
5 months
Open
UG
Total
6 months
Open
UG
Total
96,000
0
96,000
126,000
0
126,000
156,000
0
156,000
120,000
4,000
124,000
150,000
5,000
155,000
180,000
6,000
186,000
120,000
16,000
136,000
150,000
20,000
170,000
180,000
24,000
204,000
Tiles
Assume: 1) send to custom fabricator who demands pre-cut "planks"
4.5 in. x 13 in. x 3-4 ft, 2) come from broken blocks of 100 cf
Block sawed into 4 planks deep
13 + 13 + 13 + 13 = 52 in.
by 13 planks wide
4.5 in. + .25 in." (kerf) x 13 = 61.75 in.
4 x 13 = 52, -10% break or imperfect = 47
7 tiles wide .375 in. + .25 in.) x 7 = 4.375 in.
by average 3.5 tiles long = 24 tiles
24 tiles x 47 planks = 1128 tiles/block
assume 17% waste tiles = 940 tiles/block
Months of Production 1990 1991 1992+
116,560 4 127,840 months
5 months
6 months
90,240
118,440
146,640
145,700 159,800
174,840 191,760