A Field Study to Assess Natural Degradation of Cyanide Species in an Inactive Leached Ore Heap.
Comba-PB; Dix-RB; McGill-SL
Proc 2nd Int'l Conf on Env Issues & Mgmt of Waste in Energy & Min Prod Balkema Pp 535-43 :535-43
The U.S. Bureau of Mines is conducting an ongoing field study to monitor the natural degradation of cyanide in a 1-million-ton spent silver ore heap at which leaching operations ceased in October 1990. Samples of the spent ore were taken at 3-month intervals during the first year, and will be taken at 6-month intervals in the second and third years. The cyanide concentrations in the heap as a function of depth and time are presented and discussed. The report describes field sampling procedures, sample preservation methods, and the laboratory investigation that was concurrently conducted to develop a sample preparation technique and a procedure for solids cyanide analyses. Water leach tests on heap samples were conducted to simulate the effect of precipitation from meteoric storm events. Results of these studies showing soluble cyanide and metal concentrations as a function of depth and time are presented and discussed.
Proc. 2nd Int'l Conf. on Env. Issues & Mgmt of Waste in Energy & Min. Prod., Balkema, Pp 535-43