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' Oxidation processes initially oxidize cyanide to ryanate, CNO-. In some cas~s ryanate ion is further oxidized to NH~+ and HC03 ; the ammonium ion may be fina~ly oxidized to nitrogen gas. The three oxidation methods that hold the most promise for destruction of cyanide are alkaline chlorination, sulfur dioxide/air (INCO Process), and hyd gen peroxide (DeGussa Process). The alkaline chlorination process destroys cyanide by o 'dation by the ' hypochlorite ion and requires a pH of at least 10.5. It is the most develo d and widely used oxidation method. However, disadvantages include the toxicity of resid al chlorine to aquatic life, difficulty of handling chlorine, and preferential oxidation of thi ryanate. The DeGussa Process destroys cyanide with hydrogen peroxide in the presen of a copper catalyst. It is a simple process that is not particularly pH-dependent and d snot produce ' any toxic intermediates (HZOZ decomposes to OZ + HZO), and is applicabl to slurries as well as liquids. However, hydrogen peroxide is quite expensive. ' The INCO Process uses sulfur dioxide and air in the presence of a copper cat lyst, to oxidize free and WAD ryanide. The INCO process preferentially oxidizes the more toxic metallo- ' cyanide complexes ahead of the less toxic thioryanate. The process also ' obilizes heavy metals by precipitation as hydroxides (this is true for the DeGussa Process swell) and is applicable to both solutions and slurries. Disadvantages include: potentia mishaps with ' sulfur dioxide, necessity of maintaining the pH within a narrow range, and a tense must be obtained and royalty fees paid in order to use the process. The INCO Proce s will be used at the Battle Mountain facility for cyanide destruction. According to Battle ountain Gold, ' high naturally-occurring levels of copper in the ore will obviate the need for a copper catalyst. ' 3.0 SCOPE OF WORK ' 3.1 Length and Nature of Contract i The contract would be one year in length (October 1992 -September 19 3) and would ' involve three samplings in the first quarter, two samplings in the second qu rter, and two samplings in the second half, for a total of seven samplings. Depending on an lyrical results, it is possible that the sampling frequenry could either increase or decrease. ' The contract would be with Battle Mountain Gold, but all reporting would be directly to the ' Contract Administrator at the Mined Land Reclamation Division or, in hi absence, the Reclamation Specialist in charge of the Battle Mountain Gold-San Luis pe 't. 1 ' RCG/Hagier, Bailty, Inc.