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The degree of supersaturation is a factor that influences the Al2O3 inclusion characteristics in steel. The influence of the addition of a large amount of Al in the molten steel on the formation, growth and morphology of Al2O3 inclusions was investigated by laboratory scale experiments. Consecutive steel samples were taken during the deoxidation process and subjected to chemical analysis (ICP-AES), automated image analysis (AIA) and scanning electron microscopy (SEM) assessment with respect to the extracted inclusions. The characterisation and quantification of Al2O3 particles show different growth processes, leading to variations in particle size distribution as well as in the morphology.

A new model is proposed for antimony deposits in the Haut-Allier area, which contain stibnite and berthierite in veins cross-cutting gneiss lenses in unmineralised schists. Thermodynamic modelling of the ore fluid shows that no Sb minerals will precipitate if buffered by alteration reactions in the host rocks. Where the flow is channelled by brittle fractures developed in gneiss lenses during uplift, contact with the buffering environment is eventually lost and Sb solubility decreases sharply as temperature drops, resulting in the precipitation of Sb minerals. The schists continue to allow pervasive flow that buffers the fluid outside the stibnite stability field., A new model is proposed for antimony deposits in the Haut-Allier area, which contain stibnite and berthierite in veins cross-cutting gneiss lenses in unmineralised schists. Thermodynamic modelling of the ore fluid shows that no Sb minerals will precipitate if buffered by alteration reactions in the host rocks. Where the flow is channelled by brittle fractures developed in gneiss lenses during uplift, contact with the buffering environment is eventually lost and Sb solubility decreases sharply as temperature drops, resulting in the precipitation of Sb minerals. The schists continue to allow pervasive flow that buffers the fluid outside the stibnite stability field.