Leaching of Oxide Copper Ores by Addition of Weak Acid from Copper Smelters

Solvent Extraction of Metal Ions from Synthetic Copper Leaching Solution Using R4NCy

Recent works suggest that the use of ionic liquids in the copper solvent extraction industry is feasible. However, the reports did not use real solutions (or synthetic solutions with various elements). This fact remains poorly established, and the interaction efficiencies are still under study. The objective of this research is to explore the extraction and stripping of the four major elements present in a copper industrial pregnant leach solution (Cu(II), Fe(III), Mn(II), and Zn(II)) using the methyltrioctyl/decylammonium bis(2,4,4-trimethylpentyl)phosphinate (R4NCy) ionic liquid as an extractant. The work conditions studied in extraction were ionic liquid concentration, initial pH, and O/A ratio, and in stripping were H2SO4 concentration and O/A ratio. The test was carried out at room temperature and ambient pressure. High efficiency and selectivity (99.82% and 113,755 over Cu(II), respectively) were observed for Fe(III) extraction over the other elements. Moreover, after the extraction test, significant difficulty in stripping Fe(III) loaded in the ionic liquid was observed (28.7% at 0.5 M of H2SO4). Finally, the present study demonstrates that the R4NCy ionic liquid is not suitable for copper extraction because it has a higher selectivity for Fe(III) and Zn(II).

Chemical Composition Data of the Main Stages of Copper Production from Sulfide Minerals in Chile: A Review to Assist Circular Economy Studies

The mining industry has faced significant challenges to maintaining copper production technically, economically, and environmentally viable. Some of the major limitations that must be overcome in the coming years are the copper ore grade decline due to its intense exploitation, the increasing requirements for environmental protection, and the need to expand and construct new tailings dams. Furthermore, the risk of a supply crisis of critical metals, such as antimony and bismuth, has prompted efforts to increase their extraction from secondary resources in copper production. Therefore, improving conventional processes and developing new technologies is crucial to satisfying the world’s metal demands, while respecting the policies of environmental organizations. Hence, it is essential that the chemical composition of each copper production stage is known for conducting these studies, which may be challenging due to the huge variability of concentration data concerning the ore extraction region, the process type, and the operational conditions. This paper presents a review of chemical composition data of the main stages of copper production from sulfide minerals, such as (1) copper minerals, (2) flotation tailings, (3) flotation concentrates, (4) slags and (5) flue dust from the smelting/converting stage, (6) copper anodes, (7) anode slimes, (8) contaminated electrolytes from the electrorefining stage, (9) electrolytes cleaned by ion-exchange resins, and (10) elution solutions from the resins. In addition, the main contributions of recent works on copper production are summarized herein. This study is focused on production sites from Chile since it is responsible for almost one-third of the world’s copper production.