Turning Waste into Treasure: From mineral-processing wastes to high-value α-Hemihydrate Gypsum

Speaker

Dr Ye Wang

Abstract

A sustainable “waste-for-waste” strategy can transform industrial waste into valuable materials while minimising environmental impact. In this work, acidic titanium white wastewater is directly used to remove iron impurities from titanium gypsum, achieving efficient impurity removal without additional chemicals. This enables a closed-loop process that improves resource utilisation and reduces secondary pollution, aligning with green chemistry and circular economy principles. More importantly, this study demonstrates a controllable route to convert low-value waste into high-performance α-hemihydrate gypsum. By integrating kinetic analysis, thermodynamic insights, and process optimisation, we reveal how reaction conditions influence crystal growth, morphology, and final material properties. A key takeaway is that dissolution–recrystallisation and process control can effectively regulate crystal size and structure, allowing the production of larger and higher-quality crystals from fine waste materials. Overall, this work highlights that integrated process design - combining waste treatment, resource recovery, and material synthesis - can create new value from industrial by-products. This concept can be extended to other waste systems, offering a general strategy for sustainable chemical engineering processes.

Bio

Ye Wang is an Associate Professor and PhD supervisor in the College of Chemical Engineering at Sichuan University. He received his PhD in Materials Engineering from The University of Tokyo and previously served as a postdoctoral researcher at Sichuan University. His research focuses on advanced materials and sustainable technologies, including high-entropy alloys and oxides, catalytic materials, energy-storage materials, and resource recovery from industrial by-products. Ye has published more than 40 papers in international journals such as ACS Applied Materials & Interfaces, Carbon, and Journal of Cleaner Production, and holds multiple Chinese invention patents. His work aims to develop green metallurgical and chemical engineering technologies for energy, environmental sustainability, and advanced materials applications.