Laserfiche WebLink
GeoScience Services 2263 Kingston Road <br />Grand Junction, CO 81503 <br />(970) 759-6709 <br />Neutralization <br />' <br />otential NP t/kt 62 130 63 63 45, 57 61 54 <br />. <br />Acid potentia((AP tlkt ! 0 0 1:5 3.4 4.7 6.8 5.3 6.4-. <br />Acidlbas;epotential <br />' t <br />' ~ ;:< <br />~~ ~~~ ; ~ ~ ~~_ <br />~ ~ <br />~ ~t ~- ;~<; .= <br />` ='->~ <br />7 <br />~ <br />(N <br />NP ): ~-; ~ ~ ~ tlkt 62 '~-~130~ 61 <br />~ 59 '41 50 ~ 56~ <br />~ 4 <br />:; <br />Based on the laboratory tests, there are several different analytical methods to quantify <br />the acid producing potential of the Cotter Mines' uranium ores and waste rock. First, the <br />pH saturated paste for all of the samples indicate pH values well above 7.0 or basic <br />conditions. Although this is screening tool, it does indicate that there is little potential for <br />the acid generation at the Cotter Mines. Perry from the Pennsylvania Department of <br />Environmental Protection reports that pH values for saturated paste test as low as 4.0 <br />have minimal potential to generate acidic waters. <br />The next evaluation for acid generation potential is the net neutralization potential (NNP) <br />that is defined as the neutralization potential (NP) minus the acid generating potential <br />(AP); <br />NNP = NP-AP <br />A NNP value of less than 20 is likely to produce acid while values greater than 20 are not <br />likely to produce acid (Lapakko, 1993). In Table 1, the NNP is listed as the acid/base <br />potential in the last row of the table. All of the values for both the ore and waste rock are <br />well above 20 indicating little potential for acid generation. Brodie et. al. (1991) <br />recommends another analysis method using the ratio of NP/AP to assess acid generating <br />potential. A NP/AP ratio of less than 3:1 indicates there is a risk for acid drainage. In <br />other words, if the neutralization potential is two times the value of the acid generating <br />potential or a NP/AP ratio of 2:1, there is a potential to generate acid at the site. NP/AP <br />ratios greater than 3:1 indicate minimal risk for acid generation. SM-18 ore and waste <br />sample showed no acid generating potential while the other mines showed ratios of 8 to <br />42, or well above the recommended ratio. It is clear from the pH paste test, NNP, and <br />