LiDonit®—A Potential Secondary Raw Material for Ceramic Applications in Concentrated Solar Energy

Abstract

Solid particles as heat absorptances and storage mediums promise enhanced energy storage densities in concentrated solar power/thermal (CSP/T) plants. Employment of metallurgical slags as a secondary precursor material for solid particle preparation is ecologically and economically beneficial. Although these processed wastes, comprised of several oxides, exhibit generally promising high-temperature properties, chemical scattering from batch to batch may result in distinct material and functional properties, which may be an obstacle for their utilization. In this study, a steelmaking slag, LiDonit (LD), produced using a unique controlled slag treatment with high reproducibility is investigated as a candidate material. The aforementioned subsequent unique slag treatment makes LD a very promising and distinguishable secondary raw material for high-temperature applications. The as-received microstructure, phase components, and chemical composition of the LD material were analyzed to understand its material properties and to assess its reproducibility. The as-received LD chunks were transferred into pellets by subsequent milling, gel-casting, and sintering stages to reveal the potential processing routes. The CSP/T-related properties of sintered pellets, such as high temperature stability, heat capacity, and solar absorptance, were also examined to reveal their potential use in CSP/T applications and expand application areas with high added value.