Laserfiche WebLink
Geo$CIE'I7C@ $G'1"VICG'S 2263 Kingston Road <br />Grand Junction, CO 81503 <br />Neutralization <br />otential (NP) ~ <br />~ tlkt <br />~ 62 <br />130 <br />63 <br />6 I - <br />~ <br /> <br />_Acid ~ential SAP) <br />` <br />_ <br />t/kt <br />~~ 0 <br />0 - <br />1.5 3 <br />3.4 45 <br />4.7 ~ ~ _ 57 <br />6.8 ~ _ 61 <br />5.3 54-~ <br />6.4 <br />Acid/base potential <br />I -- ~ - <br />(NNP )~~'; t/kt 62 ~ x`130 ~ 61 , . 59 4~1 50 56 47' <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 />5 <br />