Laserfiche WebLink
Coal Quality Data Review for Colowyo Coal Company <br />• <br />Table 3 also illustrates that moisture adversely affects the relationships <br />between the ash and Btu /lb values, especially for the Grace data. For this <br />reason, HGC generally models proximate values on a dry basis and apply <br />moisture arithmetically via surface expressions in MineScape or in reserve <br />databases. Modeling coal quality on a dry basis allows trends of the quality <br />to be observed instead of trends in moistur <br />3.3 Review of Moisture <br />HGC reviewed some previous work on the Collom Area moisture in the <br />Geocid report, and by Steve Korte. Prior to observing that the Utah drill hole <br />moisture is likely Air - Dried, instead of Total Moisture, HGC was inclined to <br />agree of the 3% moisture factor of the Utah data. However, HGC believes <br />that efforts should be placed on determining reasonable "as- shipped" or <br />product moisture values for each seam instead of factoring data toward an <br />"as- received" value that will be factored again later. <br />• <br />Therefore, HGC proposes to readdress the issue of product moisture in <br />Collom when the 2004 moisture data is available. <br />HGC performed a number of analyses to review the moisture within the <br />Collom area, and compare it to moistures in the active mine. HGC reviewed <br />the total moisture values and the available equilibrium moisture values. <br />The Collom Area drill hole data has total moisture values for the KEC and <br />Grace drill hole data. The Utah moisture data might be Air -Dried values, but <br />for the moisture review HGC compared the Utah moisture to the other <br />moisture values. <br />Directly comparing the Collom area moisture to the Mine Area product <br />moisture is somewhat problematic. Because the Mine Area data only extends <br />down through the °F" seam, only comparing the coal seams from F and <br />• above is possible. As a result, the overall Product moisture in the "Last Pass" <br />July 2004 Page 11 of 16 <br />