“…It was then stored in a desiccator with dry powders of SiO 2 (99.995% pure), Al 2 O 3 (99.99% pure), MgO (99.99% pure), MnO (99% pure), FeO (99.95% pure), Ca 2 P 2 O 7 (≥99.9% pure), FeS (≥99.98% pure), and Fe (≥99.99% pure). Pure water (99.9997%) was used to prevent any scale formation in the system . To prepare the master slag, predetermined amounts of CaO, SiO 2 , Al 2 O 3 , MgO, and MnO dry powders were added into magnesia crucibles (4 cm OD, 7.6 cm height, 0.3 cm wall thickness) supplied by Ozark Technical Ceramics, Inc. (Webb City, MO) for premelting and magnesia presaturation at 1600 °C for 5 h under ambient atmosphere.…”