An experimental strategy to determine galvanic interactions affecting the reactivity of sulfide mineral concentrates

The galvanic effect between the distinct associated mineralogical phases in different mineral concentrates was evaluated using an alternative methodology. Voltammetric studies were carried out in order to analyze the electrochemical reactivity of pyrite-bearing samples naturally associated with sphalerite, sphalerite-galena and acanthite, respectively. When these phases were chemically removed from the concentrate, using selective leaching procedures, the voltammetric behavior indicated a modification of the pyrite reactivity. These modifications were directly associated with the loss of the galvanic interactions. In this study, it has been shown that even small quantities of the impurities provoke a significant effect on pyrite reactivity. The strategy proposed here may be employed to predict the reactivity of sulfide minerals in different hydrometallurgical systems. (c) 2005 Elsevier B.V. All rights reserved.