Fundamental Study on New Zinc Distilllation Process

上述研究者提出了一种新的锌电解工艺，称为铁还原锌电解工艺。在该方法中，氧化铁在第一还原阶段优先还原成金属铁，然后在第二还原阶段氧化锌被还原的金属铁还原成锌蒸气。因此，样品在第一还原阶段的经历，如反应路径，热量和气氛可能会影响氧化锌与金属铁的反应速率。从这个角度出发，进行了动力学实验，以阐明预热对氧化锌与金属铁反应速率的影响。此外，还进行了另一种实验条件下，即在氮气流下的动力学实验。然后通过应用一些动力学模型来分析这两种反应速率。主要研究结果如下：1.在真空条件下，预热可加快反应速率。这在该过程中是非常有利的。2.在氮气流下测定了反应速率常数和有效扩散系数。利用速率参数计算的反应曲线较好地再现了实验数据。在仅高出50 K的温度下，氧化锌与金属铁在氮气流下的反应速率与真空下的反应速率相当。

A new zinc distilllation process called the iron-reduction distilllation process has been proposed by the above-mentioned investigators. In the process, iron oxide is preferentially reduced to metallic iron at the first reduction stage, then at the second reduction stage zinc oxide is reduced to zinc vapor by the reduced metallic iron. Therefore, the sample experiences such as reaction path, heat and atmosphere during the first reduction stage might influence the reaction rate of zinc oxide with metallic iron. From this point of view, kinetic experiments were carried out to clarify the effect of preheating on the reaction rate of zinc oxide with metallic iron. Furthermore, another experimental condition, that is, under nitrogen stream kinetic experiments were also carried out. Both the reaction rates were then analyzed by applying some kinetic model. The results are summarized as follows :1. Preheating resulted in acceleration of the reaction rate under vacuum condition. This is significantly advantageous in the process.2. Under nitrogen stream the reaction rate constant and the effective diffusivity were determined. The calculated reaction curves using the rate parameters finely reproduced the experimental data.3. At temperature of only 50 K higher, the reaction rate of zinc oxide with metallic iron under nitrogen stream was comparable with that under vacuum.