Production of α′H-belite-CSA cement at low firing temperatures

• Published in: Cement & concrete composites 2022-11, Vol.134 (C), p.104820, Article 104820
• Main Authors: Duvallet, Tristana Y., Mahmoodabadi, Majid, Oberlink, Anne E., Robl, Thomas L., Jewell, Robert B.
• Format: Article
• Language: English
• Subjects: Calcium sulfoaluminate; Cement; Clinker; Low firing temperature; α′-belite
• ISSN: 0958-9465; 1873-393X
• DOI: 10.1016/j.cemconcomp.2022.104820

A global increase in population creates a need for infrastructure development to stimulate economic growth and improve quality of life. Concrete plays a significant role in this development due to its availability and mechanical strength. Ordinary Portland cement (OPC) has been the most utilized binder in the construction industry since its formulation. However, OPC production has an enormous energy demand and generates large quantities of CO2. This research investigates the production of a clinker, containing mainly the hydraulically activated alpha'H-belite polymorph and calcium sulfoaluminate (ye'elimite or C4A3Ś), at a lower firing temperature, using a combination of fluoride and boron oxide. This novel clinker addresses the problem of creating high strength cements at extremely low firing temperatures of 1000–1050 °C (a decrease of 450–500 °C as compared to OPC, and a decrease of 200–250 °C as compared to calcium sulfoaluminate (CSA) cement). This clinker reduces CO2 emissions from energy consumption and by producing phases with lower limestone requirements. The combination of lower firing temperatures and clinker phases that require lower limestone requirements provide a means to reduce CO2 emissions.