Investigations on Heap leaching material and potential recovery of strategic elements

摘要

The importance of rare elements, especially for the industry sector of renewable energies is well known. Our research group collaborates with a Chilean company that leaches ore using the method of conventional heap leaching with sulfuric acid to extract copper. The dumped residuals of the leaching process have been investigated for their potential concerning the content of strategic elements. Strategic elements in this context are minor and trace elements of economic interest. One important question is whether these elements are recoverable by using simple and inexpensive processes.Initial studies of recently dumped material were started on-site and continued later in the laboratory. The heap material is a mixture of coarse-grained to fine-grained ore chunks. With this material, pure water eluates were prepared in the field to investigate milieu parameters and element content. As expected, extremely high electrical conductivities (22.9 mS/cm) and low pH-values (down to 2.9) were measured in the solvent. Besides that, liquid phase samples were taken for ICP-MS analyses of elemental concentrations.