Mineral Phase Crystallization Sequence of Delta Steel Company (DSC), Ovwian-Aladja, Western Niger Delta Steelmaking Slag for Use as Material in Industry

摘要

Slag is a non-metallic by-product obtained in the refining of metals from metallic ores. Slag production at the Delta Steel Company (DSC), Ovwian-Aladja, western Niger Delta, follows the direct iron reduction steelmaking process. Fifteen company slag samples collected were examined by x-ray fluorescence, thin section petrography and electron microprobe analyses to establish the mineralogy and mineral crystallization sequence and thus explain their occurrences. The results show the presence of synthesized silicate minerals of belite, melilite and merwinite; calcium aluminate, wustite, periclase, perovskite and glass in the slag formed at between the temperatures of 1500°C and 500°C. Crystallization sequence is alpha (α) form of belite (1500°C-1420°C), alpha high (α/H) belite (1420°C-1160°C), alpha low (α/L) belite (1160°C-680°C, beta (β-) belite (680°C – 630°C), Melilite (1420°C-680°C), aluminate, merwinite, wustite, periclase, peruvskite and glass (630°C–500°C) in that order. This study has revealed that in behavior, synthetic minerals also crystallize from high to low temperature forms as is the case with natural minerals formed from silicate magmas. The forming behaviour of these minerals confers on them the important characteristics for industrial use as an industrial mineral compliment to natural materials.