Leaching of Pure Chalcocite with Reject Brine and MnO2 from Manganese Nodules

Abstract

Chalcocite (Cu2S) has the fastest kinetics of dissolution of Cu in chlorinated media of all copper sulfide minerals. Chalcocite has been identified as having economic interest due to its abundance, although the water necessary for its dissolution is scarce in many regions. In this work, the replacement of fresh water by sea water or by reject brine with high chloride content from desalination plants is analyzed. Additionally, the effect of adding MnO2 from available manganese nodules in vast quantities at the bottom of the sea is studied. Reject brine shows better results than sea water, and the addition of MnO2 to the brine significantly increases the kinetics of chalcocite dissolution in a short time. H2SO4 concentration is found to be irrelevant when working at high concentrations of chloride and MnO2. The best results, 71% Cu extractions in 48 h, are obtained for reject brine, 100 mg of MnO2 per 200 g of mineral and H2SO4 0.5 mol/L. The results are expected to contribute to a sustainable process of dissolution of chalcocite by using the reject brine from desalination plants.

Toward the Implementation of Circular Economy Strategies: An Overview of the Current Situation in Mineral Processing

“…Studies have shown that the leaching of caliche using reject brine is technically feasible and delivers similar results than using seawater (Ordóñez et al 2015(Ordóñez et al , 2017. In another study, the use of reject brine in the leaching of pure chalcocite provides better results than the use of seawater (Torres et al 2020).…”

Development of an analytical model for copper heap leaching from secondary sulfides in chloride media in an industrial environment

“…( 2) could be rewritten to include both dependences of the reaction. Then, considering the evident proportional relation between the copper recovery from secondary sulfides and chloride concentration [20,26,27,62,63], the term   is incorporated into the analytical model as factors of both scales, as shown in Equations ( 5) and ( 6). The term   i (chloride concentration, cCl) is defined as the potency of the fraction of the sampled chloride concentration (xi) over the average concentration (x) raised to a mathematical adjustment constant i, where i are the particle levels and heap height.…”

Analysis of the Dynamics of Rougher Cells on the Basis of Phenomenological Models and Discrete Event Simulation Framework

“…Chile is the largest copper producer worldwide, with a 27.9% share [2][3][4] of production and 29% of the reserves of this commodity [5]. Copper oxides processed by hydrometallurgy are becoming increasingly scarce in Chile (from 30.8% in 2015 to 12% in 2027), while copper sulphides are being found in more significant amounts [6][7][8]. The National Service of Geology and Mining [2] (SERNAGEOMIN, by his acronym in Spanish) has indicated that 39.2% of copper production takes place through hydrometallurgical processes, but most of the production (60.8%) takes place through flotation processes.…”