065 Extraction of Phosphorus and Recovery of Phosphate from Steelmaking Slag by Selective Leaching

This study addresses the critical issue of phosphorus resource management in Japan, where the depletion of natural phosphorus resources coincides with a rising demand for phosphate fertilizer. The objective is to develop a selective leaching process that efficiently extracts phosphorus and recovers phosphate from steelmaking slag. Utilizing the varying solubilities of different phases in slag at refining temperatures, the methodology involved the optimization of acid leaching to separate phosphorus from 2CaO·SiO2-3CaO·P2O5 solid solutions. The experimental results demonstrated the feasibility of recovering significant amounts of phosphorus from steelmaking slag, which could potentially reduce the import dependency for phosphate resources. The study highlights the importance of valorizing steelmaking byproducts while contributing to sustainable steel production practices in Japan. This innovative approach ensures that both resource recovery and environmental conservation are prioritized in the steel production industry.