Phase equilibria of the bismuth oxide–calcium oxide–copper oxide system at 1 atm of pure oxygen

Abstract

Liquidus phase relations of bismuth oxide–calcium oxide–copper oxide are described in pure oxygen at 1 atm. CaO is the primary phase over most of the system and CuO crystallizes first along much of the copper oxide–bismuth oxide join. Two calcium–copper oxides have primary phase fields separating those of CaO and CuO; these have limited variation in Ca:Cu but extend to high Bi 2O 3 contents. Primary phase fields of Bi–Ca oxides are limited to a region with <20% CuO and <40% CaO, but eight binary oxides have primary phase fields in that part of the diagram. A total of nine tributary reaction points, four distributary reaction points, a eutectic, a thermal maximum, and a thermal minimum were located. Melting relations between different solid phases are described.