Galvanic Effect of Pyrite on Chalcopyrite Leaching in Sulfate-Chloride Media

Synergetic effect of pyrite on strengthening bornite bioleaching by Leptospirillum ferriphilum

“…Based on these galvanic interactions, many researchers paid regard to strengthen other sulfide minerals leaching by adding pyrite (Chandraprabha and Natarajan, 2006;Dutrizac et al, 1971;Mehta and Murr, 1982;Ruiz et al, 2014;Zhao et al, 2015b). Berry et al (1978) investigated the galvanic interaction between chalcopyrite and…”

Effect of externally adding pyrite and electrical current on galvanic leaching of chalcopyrite concentrate

“…It should be noted that such discrepancy can be originated from the mineralogical properties of the materials tested. Further, Ruiz et al (2015) examined the galvanic effect of pyrite addition on chalcopyrite leaching in H2SO4-NaClO2 solution and Py:Cp ratios of 2:1, 4:1 and 8:1 (pyrite 9.1 µm, chalcopyrite 10.6 µm, 0.2 mol/L of H2SO4, 1 mol/L of NaCl, 1000 rpm, 100 °C and 0.3 L/min of O2). They found out that galvanic interaction between chalcopyrite and pyrite led to an increase in chalcopyrite dissolution only in a short time leaching.…”

“…They concluded that the addition of pyrite increases chalcopyrite dissolution at a short leaching time, mainly with the galvanic interaction between the two minerals (Koleini et al, 2011;Vakylabad et al, 2011;Ruiz et al, 2015;Salehi et al, 2016;Zhao et al, 2016). In addition to that, controlling redox potential in an optimum range may eliminate the formation of passive layers on the mineral surface (Koleini et al, 2011;Ahmadi et al, 2012;Lotfalian et al, 2015;Ruiz et al, 2015;Salehi et al, 2016;Zhao et al, 2016). In this regard, Ruiz et al (2015) assessed the galvanic effect between chalcopyrite and pyrite.…”

“…In addition to that, controlling redox potential in an optimum range may eliminate the formation of passive layers on the mineral surface (Koleini et al, 2011;Ahmadi et al, 2012;Lotfalian et al, 2015;Ruiz et al, 2015;Salehi et al, 2016;Zhao et al, 2016). In this regard, Ruiz et al (2015) assessed the galvanic effect between chalcopyrite and pyrite. Their results indicated that a very high pyrite: chalcopyrite ratio (8:1) was required to reach a fair efficiency, making it extremely difficult for being implemented in a large and industrial scale.…”

“…Technically, chalcopyrite leaching rate is mainly limited by an anodic half-reaction (Haque and Norgate, 2014;Li et al, 2018;Mahedi et al, 2019); while an investigation explored that it happened because of a cathodic half-reaction (Tshilombo, 2006). As a result of galvanic interaction between chalcopyrite and pyrite, the cathodic half-cell of the dissolution reaction (reduction of the active oxidant in the system) occurs on the pyrite particle's surface, and this mineral becomes galvanically protected, decreasing its dissolution rate (Ruiz et al, 2015). In this context, by assessing the effect of various parameters (temperature, agitation speed, pyrite to chalcopyrite ratio, grain size, and potential of solution), Salehi et al (2016) found that the maximum copper recovery was acquired after 24 hours in the optimal conditions of 4:1 pyrite to chalcopyrite ratio, 50 °C and <38 µm grains, such that the galvanic interaction between pyrite and chalcopyrite intensified the electrochemical reactions.…”