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02~25i99 15:20 E ~B2 356 8917 net let lamed Lab 1B <br />• ~4cC:l,EI.LAND 1.ABU1tA1Y)R1E.4, 1NC. <br />Il)lo /neF ruin, :+part.. Novn,hi N'71q__-; U: / 156Ii0U <br />FAX `, i7: (IiP.N91i <br />9TA7'IC AGP/ANP TEST PR07'000I. <br />l;XECUTIVE SUMMARY <br />Several static acid generation/acid neutralisation potential (ACP/ANP) tests are <br />available to predict the acid mine drainage potential from hard rock Ittitung waste <br />materials (uunc waste, process waste, overburden, etc.). Static tests are used [o obtain <br />preliminary waste rock characteriratiun data with respett w AGP/ANY. 1f static test <br />results do nut meet regulatory criteria (state mandated), kinetic test data is usually <br />requireJ. A partial listing of av.dlaMe tests is attached. Standard Acid Base Accounting <br />(ABA), Modified Acid }3asu Accounting (Mod. ABA), and Peroxide Uxidiza}]le <br />(1'cr. Ox.) static test ]nethods will be described herein. Pruced+lres for determination of <br />ANP are the same fur all three static test Ittetllods, and will be discussed in a separate <br />section. <br />Tltc standard ABA static trst overstates the acid generation polelllial of a waste rock <br />sample because t}+e ACP is based solely nn the total sulfur cunterit which includes non <br />• acidic sulfate and/or elemcutal sulfur components, rL] exception, of course, is a sample <br />where the total sulfur is all sulfide sulfur. <br />I'lie Mud ABA procedure is essentially the same tis the ABA except that a sulfur <br />speciation is conducted sit that the AGY can be based un the sulfide sulfur content <br />rather than on total sulfur content of the waste rock. The Mod ABA method may still <br />grossly overstate the A(iP because the nun-readily oxidisable sulfide mineral content <br />(i.c.. galena, sphalerite, etc.) is included in the sulfide sulfur content of the waste rock <br />fCCd. <br />The Per. Ox slatir lest method in many cases more accurately predicts the behavior of <br />sample subjected to a modified humidity cell kinetic test because the AGP is based on <br />the readily oxidizalllc sulfide sulfur content (pyrite). Yyritc is usually the most abundant <br />sulfide mineral contained in mine waste materials. Natural weathering and oxidizing <br />conditions are nut sufficiently strong to produce acid from difficult to oxidize sulfide <br />minerals. Conseyucntly, It 15 felt that the Per. Oz. method more accurately predicts the <br />acwal acid mine drainage potential of the waste ruck at the minesile than does the Mad <br />ARA method. <br />An actual example is pmvidcd here for your consideration. A sample of sulfide beating <br />waste rock was used for static and lunette acid nuns drainage evaluation. A Mod ABA <br />and Per. Ox. static test was conducted olt the waste 1•rrck I'eecl. A modified humidity cell <br />• 1.. ,rw.unum vvh 11,1 Ilrwi~n <br />