Effect of B₂O₃ on structure of CaO–Al₂O₃–CaF₂–B₂O₃ molten slag using molecular dynamics simulation

To investigate the influence of B 2 O 3 on the microstructure of the CaO–Al 2 O 3 –CaF 2 slag, molecular dynamics were employed. Various performance parameters such as radial distribution functions, coordination numbers, oxygen distribution, and Q n distributions were considered. The results indicate that Al 3+ predominantly adopts a [AlO 4 ] 5– tetrahedral structure within the slag, with a minority of Al 3+ existing in the forms of [AlO 5 ] 7– and [AlO 6 ] 9– . B 3+ primarily manifests as a [BO 3 ] 3– planar triangular structure in the CaO–Al 2 O 3 –CaF 2 slag. The microstructure of the CaO–Al 2 O 3 –CaF 2 slag is characterised by a simple network of Al–O–F. The addition of B 2 O 3 content in the slag promotes the incorporation of [BO 3 ] 3– into the O–Al–F simple network, thereby displacing F – ions, and leading to the emergence of a substantial amount of complex B III –O–Al IV network structures within the Al–O–F simple network. This leads to an increase in the degree of polymerisation of the slag structure. Furthermore, the viscosity of slag system increases.