Preparation of phosphorus tailings-based lightweight aggregates via two-step sintering: Microstructure, heavy metal environmental risk, and circular economy potential - Rubin Han; Hongxiu Leng; Hui Luo; Wenbo Wu; Bukai Song; Yunrui Zhao; Bao-Jie He; Zhong-ling Zong (Journal of Environmental Chemical Engineering, 2026)