Selective oxidation of elements in metal melt and their multireaction equilibria
Selective oxidation of elements in metal melt and their multireaction equilibria
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DOI：
10.1002/srin.198801530
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发表时间：
1988-09
期刊：
影响因子：
--
通讯作者：
Shoukun Wei
中科院分区：
文献类型：
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作者：
Shoukun Wei
金属熔体中元素的氧化分为两类，如修正的Ellingham - Richardson图所示。对于第一类，两个反应的ΔG-Tlines相交处，引入了转变温度的概念。通过控制这个转变温度，可以对金属熔体进行吹炼操作，使某些元素被选择性氧化，而另一些元素在熔体中保持完整，从而可以完成这些元素的分离。该转变温度的实际应用讨论了Ni vs. S, Cr， V, Nb， Mn或P vs. C.对于ΔG-Tlines几乎并行的第二类，热力学分析表明，某些元素也可以发生选择性氧化，但随着氧化的继续，其自由能变化与另一元素的自由能变化相等，因此两种元素同时发生氧化。接着是其它元素的同时氧化，直到获得金属熔体的最终平衡组成。本文列举了选择性氧化后同时氧化的例子，包括用Al和Si对铁液进行脱氧，以及对含Nb的热金属进行氧化吹炼。用计算机计算了熔体中各参考元素的平衡组成。最后简要讨论了熔体主要成分铁在氧化过程中的作用。
Oxidation of elements in metal melt falls into two categories, as shown from the modified Ellingham‐Richardson diagram. For the first category, at which the ΔG–Tlines of two reactions intersect, a concept of transition temperature has been introduced. With control of this transition temperature, blowing operation of the metal melt could be so conducted that a certain element is selectively oxidized while the other remains intact in the melt, so that separation of these elements could be accomplished. Practical application of this transition temperature is discussed with respect to Ni vs. S, Cr, V, Nb, Mn or P vs. C. For the second category with ΔG–Tlines nearly parallel side by side, thermodynamic analysis has shown that selective oxidation of a certain element can also occur, but as oxidation continues, its free energy change becomes equal to that of another element, so that simultaneous oxidation of both elements takes place. This is followed by simultaneous oxidation of other elements, until the final equilibrium composition of the metal melt is attained. Examples of selective oxidation followed by simultaneous oxidation are set forth in respect to deoxidation of liquid iron with Al and Si, and the oxidizing blowing of Nb‐bearing hot metal. Computer calculation of the equilibrium composition of the melt with respect to the referred elements has been made. Lastly, the role in the oxidation played by Fe, the main ingredient of the melt, is briefly discussed.