Phase equilibria in the CaO-La2O3-Nb2O5 system at 1823, 1773, and 1673 K

Autor: Jiyu Qiu, Chengjun Liu, Zhengyue Liu, Deying Zhu, Yeguang Wang, Maofa Jiang
Jazyk: angličtina
Rok vydání: 2020
Předmět:
Zdroj: Journal of Asian Ceramic Societies, Vol 8, Iss 3, Pp 764-776 (2020)
Druh dokumentu: article
ISSN: 2187-0764
21870764
DOI: 10.1080/21870764.2020.1789288
Popis: Phase equilibria in the CaO-La2O3-Nb2O5 system are of great significance for the utilization and application of rare earth and Nb resources. In the present work, the phase equilibria in high w(Nb2O5) corner of the CaO-La2O3-Nb2O5 system were studied by high-temperature equilibrium and quenching technology. Based on the continuity of phase diagram, a “Concavity and Convexity Rule” was proposed to predict the reasonable range of the unknown liquidus line. Finally, the isothermal sections and liquidus projection of the CaO-La2O3-Nb2O5 phase diagram were constructed, which include the primary phase fields of CaNb2O6, LaNbO4, Ca2Nb2O7, (Ca, Nb, La)O, and related liquidus lines at 1823, 1773, and 1673 K. Moreover, the subsolidus phase field of (Ca, Nb, La)O-LaNbO4-Ca2Nb2O7 with peritectic nonvariant reaction and CaNb2O6-LaNbO4-Ca2Nb2O7 with eutectic nonvariant reaction were determined, respectively.
Databáze: Directory of Open Access Journals