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B2i 27i 99 17:31 E 7B2 376 8917 McClelland Lab 22 ]2 • environment. 7'he rate of iron mobility will increase, and must of the mobile iron will be ferric when rixidizirtg conditions are established. These data often demonstrate that oxidation is occurring by a bacterial meehardsm. Metals mobility is a very itttpurt:trtt cottsidcration if acid and oxidizing conditions are established. We recommend that an 1CP-33 element met:tls analysis be conducted on the waste rock feed. Metals analysis results for the feed arc important for determining wlticlt metals may mubilirc during the IiC kinetic test if' oxidizing conditions are established. ICP results will also determine which yuantitative metals analyses will be required un HC test extracts. We recommend that 4 week, volume weighted extract solution armposiles he prepared For specific metals analyses to sour costs. At times, an 1CP-33 metals analysis is perfilrrned un the HC test residue to establish metal mobility character on :t mats halancc basis. A reasonably accurate mass balance can, however, be obtained with data from 1CY metals analysis nn the feed solids and the quantity of specified metals mobilized during the IiC test (4 week extract cotnpusites). Metals mobility rate can also he established. Another important feature to make the kinetic text more. predictable for the long term is m obtain a mass halancc between acidity, SO;, and alkalinity content of the feed and 11C: residue. Usually, a Mud ARA and Per. ()x. static test is recommended oft the feed so that the ACiY can be based on S' content (Mod ABA) and un readily oxidizable S' content (Yee. Ux.). Static test data from both tests can then hr used to calculate, on a m:us basis, maximum available sul5ne, acidity, and alkalinity. '17tat data is [hen cumpraed to actual sulfate, acidity, and alkalinity generated during the HC test so a mass balance can he calculated. 77te ralu of acidity generation and the rate of alkalinity • consumption can not he accurately determined For a waste rock Feed which crtntaitts an alkaline (ANY) component. liespective rates cannot he accurately established because ul cltetnical ittteractinn (acid/base) hetwecu acidity and a]kalinity contained in weekly extracts. The rate of acidity generatimt can be correlated to and established by weekly SOS analysis results. The raft of alkalinity cunswnption, however, can only be established by making an ANN dctcrmination un the HC residue. Usually it is better to run a Mcxl ASA and/or Per. Qx, static test un the HC residue. MUDIFIF.D Hl1M1ll177 CLLL KINF.77C'17;ST YROCLllUKF, A nxtdifieJ humidity cell test is crntdudcd fur a minimum of 20 weeks (usually until acid production rate has slowed and is predictable) un a 1200 gram charge of waste ruck crushed to 7(10% - t/a" (F)~IOM) in size to determine acid generarion/acid neutralization potential under simulated (accelerated) natural weathering and oxidizing conditions. Crushed solids arc placed into the 3.5" I.1). x 9" high clear acrylic humidity cell onto a glass wool lined, perforated plate. The xolicls arc saturated with ll.l. H2O (pli c 5.5) before initiating the kinetic test. The HC test is conducted for a minimum of 20 weekx in 7 day cycles. Dry, Filtered cuntpressed air is pumped upwards through the solids tltc first 3 days of the 7 day cycle. • A1c('I:F,I,LANIJ I,ABI)RAl'OIt1E,S, 1NC.