Extraction of Iron and Other Metals from Copper Tailings through Leaching

Abstract

Currently, mining operations have increased the generation of tailings, which contain a variety of elements that can be valorized. In this research, tailing samples were leached with hydrochloric acid of concentrations greater than 3 M, considering the monitoring of iron, copper, aluminum, calcium and magnesium, as relevant elements of the leached solution. Time and temperature were also studied. The original tailing sample was taken by trial pits, and a size distribution analysis was performed. The process generated an insoluble solid, rich in aluminosilicates, and an acid liquid solution with different metal ions. Elemental analyses were performed on liquid samples by Atomic Absorption Spectroscopy (AAS), and solid samples by Scanning Electron Microscopy-Energy Dispersive Spectroscopy (SEM-EDX) and X-ray Diffraction (XRD). Results showed an increasing trend of the iron concentration as a function of the acid concentration. However, copper is not affected by the change in acid concentration, but by time and temperature. Aluminum decreases with acid concentration, keeps constant with time, and yields at 50 °C. In the range of the studied parameters, calcium and magnesium showed a variation without a clear trend. The elements in the acid solution prepared with a tailing from northern Chile can be recovered for subsequent applications.

The Use of Acid Leaching to Recover Metals from Tailings: A Review

“…In 2022, researcher Santibáñez-Velásquez [45] conducted comprehensive leaching experiments on tailings material from northern Chile to extract iron and other metals. The tailings underwent meticulous chemical characterization involving SEM-EDS, XRD, and granulometric analysis using Ro-Tap equipment.…”

“…The uncertainty surrounding the behavior of tailings deposits has spurred the implementation of metallurgical procedures. Indeed, researchers have proposed diverse methodologies for recovering valuable minerals from these tailings, including bioremediation [23], bioleaching [4,24], phytostabilization [6,25], flotation [5,26], geopolymers [27], agitated acid leaching [22,[28][29][30][31][32][33][34][35][36][37][38][39][40][41][42][43][44][45][46]-both in columns [47,48] and in autoclave [49,50]-and even utilizing this waste as a raw material for cement production in the construction industry [51][52][53].…”

The Extraction of Copper from Chalcopyrite Concentrate with Hydrogen Peroxide in Sulfuric Acid Solution

“…Traditionally, the main technology for copper extraction from its ores and concentrates was pyrometallurgy, but the gradual depletion of rich ore deposits and growing environmental concerns over pyrometallurgical processing have made the search for hydrometallurgical processes more attractive [2]. In particular, in recent years, extensive research has been carried out to identify hydrometallurgical processes that can be used for the treatment of low-grade ores and sulfide concentrates [3][4][5] as well as for the treatment of tailings and secondary raw materials [6][7][8].…”