Behavior of Slag Foaming with Reduction of Iron Oxide in Molten Slags by Graphite
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Behavior of slag foaming was investigated under the condition of iron oxide reduction by graphite in CaO–Li<sub>2</sub>O–SiO<sub>2</sub>–Al<sub>2</sub>O<sub>3</sub> slag systems. Experiments were carried out at 1573 K, under Ar gas atmosphere with a flow rate of 1000 N cm<sup>3</sup>/min. The SiO<sub>2</sub> molar fraction of the primary slag was varied between 0.33 and 0.49. The initial concentration of iron oxide in the molten slag was varied between 3 and 15 mass%. The content of sulfur ranged from 0 to 0.68 mass%. The rotation speed of graphite rod was kept constant at 1.67 s<sup>–1</sup>. The slag foaming is evaluated by the ratio of the volume of the gas contained in slag to the total volume of foaming slag, namely gas holdup, ε.<br> The slag foaming is mainly affected by the CO gas evolution rate. The slag is not foamed when the CO gas evolution rate is less than a critical value. Then with the increase in CO gas evolution rate, the slag foaming becomes vigorous and approaches to a plateau value. Addition of sulfur suppresses the slag foaming and silica favors slag foaming a little. <br> A simple fluid mechanics model, called drift-flux analysis, can be used to fit the present experimental results.
- Transactions of the Iron and Steel Institute of Japan
Transactions of the Iron and Steel Institute of Japan 38(12), 1339-1345, 1998-12-15
The Iron and Steel Institute of Japan