Laserfiche WebLink
�ITASCK <br /> Denver, Inc. <br /> 3.0 STATIC TESTING <br /> ABA and XRD analyses were performed on each of the 29 Phase I samples as part of the WRCS. <br /> Additionally, NAG, solid-phase, and MWMP testing was performed on each of the 12 Phase II <br /> samples. All testing except for the XRD analyses was conducted by ACZ Laboratories, Inc. (ACZ), <br /> located in Steamboat Springs, Colorado. The XRD analyses were performed by the University of <br /> British Columbia Department of Earth, Ocean and Atmospheric Sciences. This section details the <br /> results of all the static testing conducted as part of the WRCS. <br /> 3.1 ACID-BASE ACCOUNTING <br /> Acid-base accounting is a method used to determine the balance of potential acid-generation <br /> and acid-neutralization capacities present in rock. ABA testing using the Nevada Modified Sobek <br /> method (NDEP 2015) was conducted on each of the 29 WRCS Phase I samples. <br /> 3.1.1 Method <br /> Acid-base accounting testing typically includes three parts: characterization of the sample AGP, <br /> ANP, and paste pH. The method for each of these parts is discussed below. <br /> 3.1.1.1 Paste pH <br /> A saturated paste was prepared by adding deionized water to samples that had been pulverized <br /> to less than 150 mesh and allowed to stand for 1 hour. The pH of the paste was then measured <br /> using a pH electrode (NDEP 2015). <br /> 3.1.1.2 Acid-Generation Potential <br /> Sulfide minerals, most notably pyrite (FeS2), are typically the dominant acid-generating minerals. <br /> As shown in Equation 3.1 below, pyrite releases acidity as it is oxidized by dissolved oxygen (or <br /> ferric iron). In ABA testing, it is assumed that Equation 3.1 describes the oxidation of all sulfide <br /> 10 <br />