Dissolution of pure chalcopyrite with manganese nodules and waste water

Leaching Chalcopyrite with High MnO2 and Chloride Concentrations

“…There have been few studies on acid leaching of chalcopyrite using marine nodules (MnO 2 ) as an oxidizing agent [26][27][28][29]. These studies showed that good copper dissolution rates of chalcopyrite can be obtained at room temperature, provided that the MnO 2 /CuFeS 2 rate is high.…”

“…The proposed reaction for chalcopyrite leaching with magnesium nodules is expressed as follows [29]: Equation 1represents dissolving copper in a sulfur-chloride medium, owing to the use of sulfuric acid and the high presence of chloride (wastewater) in the system. Among the advantages of leaching in a chlorinated rather than sulphated environment is increased leaching kinetics, the generation of elemental sulfur and cupric and/or cuprous ions are stable in the form of chloride complexes.…”

“…While the calcium in wastewater and the manganese nodules reacts with the sulfate in the system, forming Equation (2) which is spontaneous and more likely to occur under normal conditions with the elements present (higher affinity of sulfate for calcium than magnesium and manganese in solution), the calcium sulfate formed is insoluble because calcium precipitates when it comes in contact with sulfate, nitrates and other elements. Equation (1) shows a 2/1 MnO 2 /CuFeS 2 ratio for leaching copper using manganese nodules as an oxidizing agent, which was initially proposed by Toro et al [29], but the best conditions to leach copper is at a 4/1 MnO 2 /CuFeS 2 ratio. The values of the Gibbs free energy were calculated using the software HSC 5.1.…”

“…There are few studies for the dissolution of chalcopyrite incorporating MnO 2 and chloride in the system [26][27][28][29], achieving positive results in the extraction of Cu at room temperature, mainly evaluating the concentration of MnO 2 in the system. Previously, Toro et al [29] conducted an investigation in which they evaluated the use of wastewater with high chloride, seawater and manganese nodules contents, for the dissolution of chalcopyrite in an acidic medium. In this investigation, the effect on the concentration of MnO 2 , chloride and agitation speed in the system was evaluated.…”

Leaching of Pure Chalcocite in a Chloride Media Using Waste Water at High Temperature

“…The common factor is the addition of chloride, since when no chloride is added, the dissolution decreases, and there is a tendency to passivation. Chloride ions promote the formation of long sulfide crystals, which allow the penetration of the reagent through the passivating layer [18]. In this work, we study the leaching of pure chalcocite in chloride media from wastewater with the application of high temperatures to analyze its dissolution kinetics and calculate the activation energy of the leaching process.…”