Open circuit potential and leaching rate of pyrite in cupric chloride solution

Direct Cupric Chloride Leaching of Gold from Refractory Sulfide Ore: Process Simulation and Life Cycle Assessment

“…Therefore, direct chloride leaching in two chloride leaching conditions with different chemical concentrations was investigated: the Severe case and the Base case. In the Severe case ([Cu 2+ ] = 70 g/L, [Cl − ] = 180 g/L, [Br − ] = 5 g/ L, T = 95°C, atmospheric pressure), aggressive leaching conditions are predicted to facilitate faster leaching of refractory sulfides (Elomaa et al 2018). The expected disadvantage of the Severe case is the increased environmental burden due to increased chemical consumption (Elomaa et al 2020a), although lower reactor energy consumption is expected due to the faster leaching kinetics (15 h in the Total oxidation scenario and 7.5 h in the Partial sulfide oxidation scenario).…”

“…This could potentially mitigate the negative effects of high chemical consumption. In the Base case, less aggressive conditions are used ([Cu 2+ ] = 40 g/L, [Cl − ] = 125 g/L, [Br − ] = 5 g/L, T = 95°C, atmospheric pressure) and this is expected to facilitate the fast leaching of gold but also the sufficient leaching of refractory sulfides (Elomaa et al 2018;Seisko, Aromaa and Lundström 2019). However, the leaching times are slightly higher (20 h in the Total oxidation scenario and 10 h in the Partial sulfide oxidation scenario), indicating an increase in energy consumption.…”

“…However, the leaching times are slightly higher (20 h in the Total oxidation scenario and 10 h in the Partial sulfide oxidation scenario), indicating an increase in energy consumption. It should be acknowledged that the retention times are estimated from a model obtained by electrochemical measurements (Elomaa et al 2018), whereas in real processing even longer retention times may be necessary.…”