| Abstrakt: |
During the cyanide leaching process of gold and silver, ores that come from the transition zones which typically contains low levels of sulfide may produce one or more of the following reduced sulfur species: sulfide (HS-), polysulfides (Sn2-), thiocyanate (SCN-), thiosulfate (S2O32-), trithionate (S3O62-), tetrathionate (S4O62-), pentathionate (S5O62-) and hexathionate (S6O62-). The actual speciation of the reduced sulfur species in the circuits will primarily depend on the redox potential, pH, cyanide levels and existing sulfur species in recycled process water, as well as the presence of other reactive metal species. Development of an accurate analytical method for sulfur species in cyanide leaching units of gold ores where sulfur speciation occurs has an important role in explaining the metal recovery deviations. This study presents the speciation of sulfur species and development of an ion chromatography method to analyze the reduced sulfur species thiocyanate, thiosulfate, trithionate and tetrathionate in cyanide leaching circuits for gold ores. The method developed has resulted in the precise quantification of target sulfur species in leach solutions. [ABSTRACT FROM AUTHOR] |
