Published at Ceramics International – Upcycling copper slag into high-performance spinel-based ceramics with integrated solar absorption and storage

Abstract:
Solid solar absorption/storage material (SSAM) is the crucial component for next generation concentrating solar power (CSP) system, which could promote global carbon neutrality. However, the comprehensive absorption/storage performance of SSAM at low cost has not been realized, thereby hindering its practical application. To address this problem, Fe/Si-rich copper slag, as abundant solid waste, was used as the main raw material to develop novel SSAM by introducing MgO/Al₂O₃ additives in present work. This kind of SSAM is composed of (Mg,Fe)(Fe,Al)₂O₄ spinel and (Mg_xFe_2-x)SiO₄ forsterite as main crystalline phases with high solar absorptance of 91.93%, due to impurity energy level absorption and lattice vibration absorption. Moreover, the material possesses excellent storage potential, including thermal storage density of 1194.83 J/g, thermal conductivity of 4.69 W/(m·K) and specific heat capacity of 1.37 J/(g·K). Crucially, the SSAM maintains remarkable mechanical integrity at elevated temperatures, exhibiting a bending strength of 77.96 MPa even at 1000 °C (106.23 MPa at room temperature). Furthermore, it demonstrates outstanding thermal shock resistance and superior high-temperature wear resistance, ensuring long-term operational reliability under harsh service conditions. This spinel/forsterite SSAM with high absorption/storage performance and low cost, displays significant potential for next generation CSP system.

Dong Zhu, Yawei Li, Qinghu Wang, Shaobai Sang, Heng Wang, Yibiao Xu, Yiwei Li, Emad.M.M Ewais, Upcycling copper slag into high-performance spinel-based ceramics with integrated solar absorption  and storage, Ceramics International, 2026, ISSN 0272-8842, https://doi.org/10.1016/j.ceramint.2026.06.198