Valorizing end-of-life LCD scraps after indium recovery

For the WEEE European directives, efforts must be undertaken to reuse or securely dispose LCD waste, however no practical process was reported yet, although it is possible to recover many glass, plastic and precious metals, in particular Indium. Indium is one of the element included by the European Commission in the list of 20 raw materials critical for economic importance and high supply risk. The work aims to valorize LCD scraps after Indium recovery with low cost applications both economically and environmentally speaking. Applications were been explored by many researchers, although most focused only on the use of glass powder waste LCD to design concrete. The work deals the use of LCD scraps as it is after cross-current leaching of Indium with H2SO4. The experimental work consists of scraps characterization, washing procedure optimization to remove any residual acid, mortar production, performance testing, and LCA. The results show that LCD scraps exhibit little or no pozzolanic activity. This delay on reactivity can be ascribed to organic residues that prevent the pozzolanic reaction and/or to a lower fineness than that typical of binders or fillers. For this reason the actual investigation focuses to exploit the waste as partial replacement of traditional aggregates.