1992-06-10_REVISION - M1988112 (3)

Home Browse Search

:HIdUL06IES IfJC June 9, 1992 TEL~3C~3-792-563 • Dr. James A. Pendleton Technical and Scientific Coordinator Colorado Mined Land Reclamation Division 1313 Sherman Street, Room 215 Denver, Colorado 89203 bear Dr. Pendleton ?un 09 92 2r~:n~ Na.002 P.02 • I am in receipt of the copy of "Technical Revision No. 007, Tailings Cyanide Detoxification Using Hydrogen Peroxide" referring to the San Luis Project, Permit No. M-88-112, as forwarded to your office from Mr. Andre J. Douchane of Battle Mountain Gold Company. My copy of the document was received from the offices of Mr. Dean Massey on~June 1, 1992. The following comments refer to the details of the Technical Revision and to th~e relationship this proposed new approach to reducing cyanide in the San Luis tailirgs pond(s) bears to the ongoing CYTOX process at this site: The proposed use of hydrogen peroxide to reduce cyanide in the ponds is relatively proven acwrding to the document, but there is no date to demonstrate that the target level o[ 4 ppm total cyanide can be achi4:ved by this method. The use of the CYTOX process in combination with the peroxide treatment is confusing since the Insoluble products of the CYTOX rea ent (iron•zinc-cyanide wmplexes) will be deposited In the tail~ngs impoundment and thus provide a lUture threat of cyanide release ugder some conditions. The limited water analysis data I have seen for the tailings pond water indicates relatively low levels of Iron and high copper levels (wtth~out CY7'()X reagent addition) and thus we would expect that pero de ALONE would destroy both free and Copper-complexed cyanide with ut the use of the CYTOX process as en adjunct. L060992DEH 1