Tricalcium aluminate is an important phase of Portland clinker. In this paper, three polymorphs of C3A were prepared by means of the solid-state synthesis method using intensive milling of the raw material mixture which was doped with various amounts of Na2O and sintered at a temperature of 1300 °C for 2 h. The final products were evaluated through X-ray diffraction using Rietveld analysis. The effect of the Na dopant content on the change in the crystalline structure of tricalcium aluminate was studied. It was proven that the given preparation procedure, which differed from other studies, was close to the real conditions of the formation of Portland clinker, and it was possible to prepare a mixture of different polymorphs of calcium aluminate. Fundamental changes in the crystal structure occurred in the range of 3-4% Na, when the cubic structure changes to orthorhombic. At a dosage of Na dopant above 4%, the orthorhombic structure changes to a monoclinic structure. There are no clearly defined boundaries for the existence of individual C3A phases; these phases arise at the same time and overlap each other in the areas of their formation at different Na doses.

Department of Geological Sciences Faculty of Science Masaryk University Kotlářská 267 2 611 37 Brno Czech Republic

Faculty of Civil Engineering Brno University of Technology Veveří 331 95 602 00 Brno Czech Republic

Research Institute for Building Materials Hněvkovského 30 65 617 00 Brno Czech Republic

Zobrazit více v PubMed

Scrivener K.L., John V.M., Gartner E.M. Eco-efficient cements: Potential economically viable solutions for a low-CO2 cement-based materials industry. Cem. Concr. Res. 2018;114:2–26. doi: 10.1016/j.cemconres.2018.03.015. DOI

CEMBUREAU, 2050 Carbon Neutrality Roadmap. [(accessed on 29 November 2023)]. Available online: https://cembureau.eu/library/reports/2050-carbon-neutrality-roadmap/

Schneider M., Hoenig V., Ruppert J., Rickert J. The cement plant of tomorrow. Cem. Concr. Res. 2023;173:107290. doi: 10.1016/j.cemconres.2023.107290. DOI

CEMBUREAU, Energy Assessment for CCUS Options EU Cement Sector. [(accessed on 29 November 2023)]. Available online: https://cembureau.eu/media/bucbkisd/230503-tno-r10586-1-energy-assessment-for-ccus-options-eu-cement-sector-final.pdf.

Szabó L., Hidalgo I., Císcar J.C., Soria A., Russ P. Energy Consumption and CO2 Emissions from the World Cement Industry. European Commission Joint Research Center; Brussels, Belgium: 2003.

Mokrzycki E., Uliasz-Bocheńczyk A. Alternative fuels for the cement industry. Appl. Energy. 2003;74:95–100. doi: 10.1016/S0306-2619(02)00135-6. DOI

Taylor H.F.W. Cement Chemistry. Academic Press; London, UK: 1990.

Hewlett P.C. Leas´s Chemistry of Cement and Concrete. Arnold; London, UK: 1998. pp. 131–193.

Wesselsky A., Jensen O.M. Synthesis of pure Portland cement phases. Cem. Concr. Res. 2009;39:973–980. doi: 10.1016/j.cemconres.2009.07.013. DOI

Rodríguez N.H., Martínez-Ramírez S., Blanco-Varela M.T., Donatello S., Guillem M., Puig J., Fos C., Larrotcha E., Flores J. The effect of using thermally dried sewage sludge as an alternative fuel on Portland cement clinker production. J. Clean. Prod. 2013;52:94–102. doi: 10.1016/j.jclepro.2013.02.026. DOI

Nakomcic-Smaragdakis B., Cepic Z., Senk N., Doric J., Radovanovic L. Use of scrap tires in cement production and their impact on nitrogen and sulfur oxides emissions. Energy Sources. 2016;38:485–493. doi: 10.1080/15567036.2013.787473. DOI

Tsiliyannis C.A. Alternative fuels in cement manufacturing: Modeling for process optimization under direct and compound operation. Fuel. 2012;99:20–39. doi: 10.1016/j.fuel.2012.03.036. DOI

Bingrong L., Wei Y., Peng C., Zhou H., Li S., Wang S. Influence of Fe2O3 on the hydration kinetics of tricalcium aluminate. J. Eur. Ceram. Soc. 2023;43:6550–6561.

Chen S., Chen G., Cheng J. Effect of additives on the hydration resistance of materials synthesized from the magnesia-calcia system. J. Am. Ceram. Soc. 2000;88:1810–1812. doi: 10.1111/j.1151-2916.2000.tb01469.x. DOI

Tian Y., Pan X., Yu H., Tu G. Formation mechanism and crystal simulation of Na2O-doped calcium aluminate compounds. Trans. Nonferrous Met. Soc. China. 2016;26:849–858. doi: 10.1016/S1003-6326(16)64176-6. DOI

Boikova A.I., Domanskii A.I., Paramonova V.A., Stavitskaya G.P., Nikushchenko V.M. The influence of sodium oxide on the structure and properties of tricalcium aluminate. Cem. Concr. Res. 1977;7:483–491. doi: 10.1016/0008-8846(77)90110-7. DOI

Mondal P., Jeffrey J.W. Crystal structure of tricalcium aluminate, Ca3Al2O6. Acta Crystallogr. 1975;31:689–697. doi: 10.1107/S0567740875003639. DOI

Nguyen M., Sokolář R. Formation and influence of magnesium-alumina spinel on the properties of refractory forsterite-spinel ceramics. Mater. Technol. 2020;54:135–141. doi: 10.17222/mit.2019.198. DOI

Gobbo L., Sant’Agostino L., Garcez L. C3A polymorphs related to industrial clinker alkalies content. Cem. Concr. Res. 2004;34:657–664. doi: 10.1016/j.cemconres.2003.10.020. DOI

Dietmar S., Wistuba S. Crystal structure refinement and hydration behaviour of doped tricalcium aluminate. Cem. Concr. Res. 2006;36:2011–2020.

Nishi F., Takeuchi Y. Aluminum oxide (Al6O18) rings of tetrahedra in the structure of sodium calcium aluminate (Ca8.5NaAl6O18) Acta Crystallografica. 1975;31:1169–1173. doi: 10.1107/S0567740875004736. DOI

Götz-Neunhoeffer F., Neubauer J. Crystal structure refinement of Na-substituted C3A by Rietveld analysis and quantification in OPC; Proceedings of the 10th International Congress on the Chemistry of Cement; Gothenburg, Sweden. 2–6 June 1997.

Varma S.P., Wall C.D. A monoclinic tricalcium aluminate (C3A) phase in a commercial Portland cement clinker. Cem. Concr. Res. 1981;11:567–574. doi: 10.1016/0008-8846(81)90086-7. DOI

Singh V.K., Ali M.M., Mandal U.K. Formation Kinetics of Calcium Aluminates. J. Am. Ceram. Soc. 1990;73:872–876. doi: 10.1111/j.1151-2916.1990.tb05128.x. DOI

Mohamed B.M., Sharp J.H. Kinetics and mechanism of formation of tricalcium aluminate, Ca3Al2O6. Thermochim. Acta. 2002;388:105–114. doi: 10.1016/S0040-6031(02)00035-7. DOI

López F.A., Martín M.I., Alguacil F.J., Sergio Ramírez M., González J.R. Synthesis of Calcium Aluminates from Non-Saline Aluminum Dross. Materials. 2019;12:1837. doi: 10.3390/ma12111837. PubMed DOI PMC

Pati R.K., Panda A.B., Pramanik P. Preparation of Nanocrystalline Calcium Aluminate Powders. J. Mater. Synth. Process. 2002;10:157–161. doi: 10.1023/A:1023013913102. DOI

Mandic V., Kurajica S. The influence of solvents on sol–gel derived calcium aluminate. Mater. Sci. Semicond. Process. 2015;38:306–313. doi: 10.1016/j.mssp.2015.01.004. DOI

Ghoroi C., Suresh A.K. Solid–solid reaction kinetics: Formation of tricalcium aluminate. AIChE J. 2007;53:502–513. doi: 10.1002/aic.11086. DOI

Shin G.Y., Glasser F.P. Interdependence of sodium and potassium substitution on tricalcium aluminate. Cem. Concr. Res. 1982;13:135–170. doi: 10.1016/0008-8846(83)90137-0. DOI

Ostrowski C., Żelazny J. Solid Solutions of Calcium Aluminates C3A, C12A7 and CA with Sodium Oxide. J. Therm. Anal. Calorim. 2004;75:867–885. doi: 10.1023/B:JTAN.0000027182.40442.fe. DOI

Scherrer P. Bestimmung der Grosse und der Inneren Struktur von Kolloidteilchen Mittels Rontgenstrahlen. Nachrichten Von Der Ges. Der Wiss. Math.-Phys. Kl. 1918;2:98–100.

Warren B.E. X-ray Diffraction. Addison-Wesley; Boston, MA, USA: 1969.

Ravaszová S., Dvořák K. Development of Crystallinity of Triclinic Polymorph of Tricalcium Silicate. Materials. 2020;13:3734. doi: 10.3390/ma13173734. PubMed DOI PMC