Investigations on Heap leaching material and potential recovery of strategic elements

The significance of rare elements for the renewable energy sector is increasingly recognized. This study aims to evaluate the potential recovery of strategic elements from heap leaching residuals, in collaboration with a Chilean company utilizing sulfuric acid for copper extraction. Initial on-site and subsequent laboratory investigations were conducted on recently dumped heap material, which exhibited high electrical conductivities and low pH values. Water eluates were prepared to analyze the environmental parameters and elemental content, revealing critical information on extractable strategic elements. Techniques such as inductively coupled plasma mass spectrometry (ICP-MS) were employed to assess elemental concentrations. Furthermore, a sequential extraction methodology was developed to gauge the mobility of various elements by applying increasingly stronger leaching solutions. This approach was not only enhanced but also modified to permit the use of cost-effective extraction agents, including seawater and sulfuric acid. The article outlines findings from three distinct sequential extraction strategies: complete sequential extraction, a shortened version, and a modified method involving specific solvents, ultimately detailing their effectiveness in extracting strategic elements from residual materials. This research contributes valuable insights into sustainable practices for resource recovery in mining.