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• <br />static, the H2O2 will eventually flow through tha 5vli:i5, :rough at <br />a much reduced rate, and the stratification just described will <br />develop. As long as the unreacted H2o2 and WAD cyanide come in <br />contact, the reaction will continue. <br />WAD cyanide destruction using the INCO process will take place <br />within the reaction vessels, not in the pond. Therefore, the <br />problem of mixing within the tailings solids will not arise. <br />once the tailings ponds' cyanide concentrations reach the <br />appropriate low levels, and provided of course that they remain <br />low, one complete cycling of the interstitial fluids in the <br />tailings solids through the underdrain should remove the WAD <br />cyanide from those interstitial fluids. In the case before us, <br />wherein WAD cyanide is being removed through the additimn of H2O2, <br />once the collection pond cyanide concentrations reach the <br />appropriate low levels, we should be able to safely assume that <br />virtually all of the WAD cyanide has been removed. Whether the WAD <br />cyanide has been removed from the collection pond by sta~Ttup of the <br />INCO reactor will have no effect on its eventual removal because <br />the INCO process itself will remove the remainder, as well as any <br />WAD cyanide produced in the future. <br />I believe, still, that the greater problem - if there is indeed a <br />problem - may be cytox-generated metallic compounds in the tailings <br />solids. Whether the Zn cyanates will be stable into perpetuity, <br />whether they will break down all at once, or whether they will <br />break down slowly, none of this is known. Until we have leach <br />tests on the CYTOX-affected tailings, we cannot make informed <br />predictions about the chemical stability of the tailings. <br />cc: Humphries <br />Oehler <br />Sorenson <br />Stevens <br />HP/hp <br />m:\min\hhp\tails.mem <br />