2013-04-10_PERMIT FILE - C1981019 ‎(78)‎

• Permit No: C1981019
• IBM Index Class Name: Permit File
• Doc Date: 4/10/2013
• Doc Name: Geology Pre-Feasibility Report
• Section_Exhibit Name: Volume 17 Exhibit 6 Item 7
• Media Type: D
• Archive: No

0.35
0.30
0.25
0.20
0.15
0.10
0.05
0.00
5.00
Collom Area Geology Pre - Feasibility Report
Figure 6.3
Moisture Distribution of 2004 Drilling by Moisture Type
10.00 15.00 20.00
Moisture
Total Moisture —EQ Moisture Colowyo Product Moisfure
25.00
Given these data, CMA moisture estimates should be based upon equilibrium
moisture values. To determine the predicted product moisture for the CMA,
additional work needs to be performed to determine the relationship of
equilibrium moisture values to product moisture values. This work should
compare Colowyo West Pit drill hole equilibrium moisture values to West Pit
production moisture values.
6.3 Review Apparent Specific Gravity
Colowyo, along with most coal mines in the US, uses apparent specific
gravity (ASG) as the density factor for tonnage calculations. RTTS
highlighted a concern with the density values being determined for the
Collom project area. Specifically, the correlation between ash and ASG of
the 2004 coal quality data was not as "tight" as would be expected. The data
shows a constant ASG value (1.31) was determined over large range of ash
values (3% to 12 %). In response to RTTS' concerns, the Collom Exploration
August 2005 Page 23 of 38
.1-.1 ab C : ' 7';
Product Moisture Mean: 16.61
a
,x:
lx
sgtk7'
wxn, '" '
EQ Moisture Mean 15.46
"i
Total Moisture Mean: 15.11
31iz
y ? a+
i
g
10.00 15.00 20.00
Moisture
Total Moisture —EQ Moisture Colowyo Product Moisfure
25.00
Given these data, CMA moisture estimates should be based upon equilibrium
moisture values. To determine the predicted product moisture for the CMA,
additional work needs to be performed to determine the relationship of
equilibrium moisture values to product moisture values. This work should
compare Colowyo West Pit drill hole equilibrium moisture values to West Pit
production moisture values.
6.3 Review Apparent Specific Gravity
Colowyo, along with most coal mines in the US, uses apparent specific
gravity (ASG) as the density factor for tonnage calculations. RTTS
highlighted a concern with the density values being determined for the
Collom project area. Specifically, the correlation between ash and ASG of
the 2004 coal quality data was not as "tight" as would be expected. The data
shows a constant ASG value (1.31) was determined over large range of ash
values (3% to 12 %). In response to RTTS' concerns, the Collom Exploration
August 2005 Page 23 of 38