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The chemistry of cyanide in the presence of reduced sulfur sources
Abstract
The chemistry of aqueous cyanide containing species in the presence of reduced sulfur sources was investigated. Reactions were studied as a function of time and tracked using novel analytical techniques developed for the analysis of the species of interest in the sample of matrix. Species of interest in this work were "free" cyanide, thiocyanate, cyanate, metallocomplexed cyanide, and various sulfur and sulfur-oxygen species. The studies were conducted under constant temperature conditions at pH values above 10.5 and in the absence of light in order to eliminate photochemically induced cyanide reaction effects. The reaction products of cyanide when in contact with pure reduced sulfur containing materials under the ideal conditions studied are reported, along with an extension of the pure minerals study results to the reactions taking place in two "real world" samples. A mass balance on the cyanide reaction products was completed for all experiments. The first portion of the research involved the development of the requisite analytical techniques and the characterization of the reaction products and kinetics of the reactions as they occurred at "pure" mineral surfaces in a heterogeneous system. The pure minerals included those sulfides most likely to be found in an actual mining operation, specifically: elemental sulfur, pyrite, pyrrhotite, chalcopyrite, bornite, covellite, chalcocite, sphalerite, realgar, orpiment, arsenopyrite, stibnite, galena, and cinnabar. The second portion of the research utilized actual samples obtained from an operating precious metals mine in Nevada. These experiments were run in an identical manner to the previous portion and the results have been characterized on the basis of their mineralogical composition.
Subject Area
Chemical engineering|Mining|Analytical chemistry
Recommended Citation
Wilmot, John Charles, "The chemistry of cyanide in the presence of reduced sulfur sources" (1997). ETD collection for University of Nebraska-Lincoln. AAI9804342.
https://digitalcommons.unl.edu/dissertations/AAI9804342