About this Abstract |
| Meeting |
2026 TMS Annual Meeting & Exhibition
|
| Symposium
|
Thermodynamics for Sustainability: An EPD Symposium in Honor of Kazuki Morita
|
| Presentation Title |
Sustainable treatment of solid titanium-gypsum-waste using acidic titanium-white-wastewater to produce high-value α-hemihydrate gypsum |
| Author(s) |
Ye Wang, wang Yuru, Ma Xiaodong |
| On-Site Speaker (Planned) |
Ye Wang |
| Abstract Scope |
Titanium gypsum is a solid waste produced when titanium dioxide manufacturers use sulfuric acid and neutralizethe waste acid with lime. The global production of titanium gypsum waste has reached 10 million tons annually.To address the environmental hazards, this study proposes a cost-effective ($2.39/ton), emission-free method tosustainably produce high-value α-hemihydrate gypsum by consuming large quantities of titanium gypsum. Theprimary iron impurity in titanium gypsum was separated (> 80 %) using titanium white waste acid, yieldinghigh-value red iron oxide (Fe2O3) and green vitriol, i.e., hydrated iron(II) sulfate (FeSO4⋅7H2O). Additionally, thethermodynamic process of in-situ dehydration of titanium gypsum at atmospheric pressure in a chlorine-free saltsolution was studied, producing large α-hemihydrate gypsum particles of 20 μm size through hydrationrecrystallization. This work enhances resource utilization efficiency, reduces environmental contaminationfrom titanium dioxide waste acid and titanium gypsum, and exemplifies an environmentally responsible processwith significant implications for the sustainable development of the titanium dioxide industry. |
| Proceedings Inclusion? |
Planned: |
| Keywords |
Sustainability, Hydrometallurgy, Recycling and Secondary Recovery |