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02i 27~9a 17:26 E 102 376 8911 McClelland Lab <br />• MODIFIED ABA STATIC TEST METHOD <br />'1'hc Mod ABA procedure is essentially the same ae the standard AAA except tha[ a <br />sulfur speciation is conducted so that the AGl' cart he based c,n the sulfide sulfur content <br />of the waste rock rather than on total sulfur content. <br />1) Measure paste pH of the pulverized solids. <br />2) Determine total sttltut by Lcco furnace. <br />3) I.)eternune sulfate sulfur (SO4) lty multi-stage U.l. H2U and HCl digestions. <br />4) Uetertnine sulfide sulfur Ity difference (S, - SU; = S") <br />NOTE: More detailed SOS (Ftazite, gypsum) and S' speciation can be performed. <br />Also, at slimes a carbon speciation is helpful. <br />ACP = S'%x 31.25 <br />ANP = Satne as standard AAA <br />NNP =ANP - ACI' (by S'%) <br />Ratio ~ ANP + AGP (by S'°1°) <br />1'EIZVXIUE OXIDILAB1.E STATIC TEST METHOD <br />}'yritic minerals begin tct change into new oxidation products when exposed to the <br />atmosphere. 'The change may proceed slowly over a long period of time before the final <br />p:nducts (yellowboy + sulfuric tlcid) are formed. Yellowhoy actually may form only <br />when the sulfate (acidic) is neutralized partially or completely by the basic component. <br />The chemical equation fur this complete change in pyrite follows: <br />• Pyrite + Uxygen + Water = Yellowboy + Sulfuric Acid <br />4 FeSt + IS OZ + 14 H2() = 4 I~c(OH), + K HtSU, <br />I'Ire use of hydrogen peroxide and temperature greatly accelerates the oxidation rate of <br />pyrite to yellawboy and sulfuric acid. <br />The Per. Ox, procedure is as follows: <br />]) Weigh 2.U grams of pulverized waste ruck sample <br />Note: if the sample contains no carbouatcs and no sulfates, and the paste yH is <br />less than 5.5, then steps 2 through S can he eliminated (nn preleach). <br />2) Place sample into a funnel fitted with filter paper with 2(lUml of 2:3 HC1 in "fttnnel- <br />full" increments. <br />3) Leach sample with I).l. H2O (funnel-full ittcremcnts) until effluent is free of <br />chloride (titration with lU% AgNUi). <br />Note: Add 3 drops of lU%, AgNO,. if a white precipitate forms, chlorides are <br />present. <br />4) Air dry filter and sample overnight, nr place in 50"C forced air oven until dry. <br />5) Carefully scrape dried sample from filter surface and thoroughly mix sample. <br />(i) Place sample inter a 300m1 tall form Itcakcr. <br />IS <br />• Mc(:LFi1..LANU I.ARURA'1'URllti, IN('. <br />