Slag Foaming and Reactions

熔渣发泡在新的熔池炼铁工艺和最先进的电炉炼钢中发挥着重要作用；这两种工艺在美国未来的炼钢中都将是重要的。以往大多数关于炉渣发泡的工作只是简单地测量发泡指数，即在任意条件下的泡沫高度或泡沫寿命。虽然这样的定性信息表明哪些炉渣容易起泡，但它几乎没有提供有关基本现象的信息。本实验将测量炉渣成分、气体流量、炉渣粘度、炉渣表面张力和温度对发泡的影响。测量不仅包括泡沫高度和寿命，还包括作为位置函数的空泡率，这是任何泡沫定量分析的关键参数之一。要研究的炉渣成分将包括与熔池冶炼和电炉炼钢有关的成分。还将研究小浓度的表面活性元素如P_2O_5和悬浮第二相粒子的影响。炉渣的起泡将与炉渣的性质相关联，质量守恒方程、动量守恒方程和能量守恒方程将被用来概括这种行为。一种与泡沫寿命有关的新型号也将进行测试。如果不存在关于该特定炉渣的此类信息，则将确定炉渣的表面张力。此外，还将测量氮气通过泡沫渣的转移速率及其与铁液的反应。

Slag foaming plays an important role in new in-bath smelting processes for producing iron and in state-of-the-art electric furnace steelmaking; both processes will be important in future steelmaking in the United States. Most previous work on slag foaming simply measured a foaming index which was the foam height or foam life for arbitrary conditions. Whereas such qualitative information indicates what slags may foam easily it gives little information concerning the basic phenomena. The present experimental work will measure foaming as a function of slag composition, gas flow rate, slag viscosity slag surface tension and temperature. The measurements will not only include foam height and life but also the void fraction as a function of position, which is one of the critical parameters in any quantitative analysis of foaming. The slag compositions to be studied will include those relative to in-bath smelting and electric furnace steelmaking. The effects of small concentrations of surface active elements such as P2O5, and of suspended second phase particles will also be investigated. The foaming of the slags will be correlated to the properties of the slag and, the equations for the conservation of mass, momentum and energy will be used to generalize the behavior. A new model concerned with foam life will also be tested. The surface tension of the slags will be determined if no such information exists for that particular slag. In addition, the rate of nitrogen transfer through a foamed slag and its reaction with liquid iron will be measured.