Reduction of Iron Oxides with Use of Microwave Heating

本文的主要研究成果如下：1.研究了微波加热过程中温度测量的几种方法。温度测量可以通过与地面连接的热电偶来实现。2.微波加热碳热还原氧化铁(1)在(Fe_2O_3：C=4：1)条件下，样品用量越少，还原速度越快，最终还原速率越高，升温越高。(2)微波功率越大，还原速率越快，最终还原速率越高。在功率为500W的情况下，碳量越大，还原速度越快，最终还原分数越高。另一方面，在功率为700W的情况下，碳量越大，还原速度越慢，最终的还原分数越低。(3)当样品形状为团块，加热时间延长30min时，还原速度变慢，最终还原分数也比粉末样品的结果低。3.与外部加热还原相比，尽管微波功率增加，但由于包杜亚反应，样品的温度仅上升了900-1000ﾟC左右。但是，随着微波功率的增加，升温速度加快，最终分馏还原程度变高。

The main results of this research are as floows.1.Several methods for temperature measurement during microwave heating were examined. Temperature measurement was possible by the thermocouple with the ground. Without carbon, it was not so easy for materials temperature to rise.2.Carbothermic reduction of iron oxide with use of microwave heating(1) In the case of (Fe_2O_3 : C=4 : 1), the less amount of sample was, the faster the reduction rate became, the higher the final fractional reduction was and the higher the sample temperature rose.(2) The higher the microwave power was added, the faster the reduction rate became and the higher the final fractional reduction was. In the case of the power 500W,the lager the amount of carbon was, the faster the reduction rate became and the higher the final fractional reduction was. On the other hand, in the case of the power 700W,the larger the amount of carbon was, the slower the reduction rate became and the lower the final fractional reduction was.(3) When the shape of the sample was briquette and the heating time was lengthened for 30 minutes, the reduction rate became slower and the final fractional teduction was also lower compared with the results in powder sample.3.Comparing with the reduction by external heating method, the temperature of the sample rose only up to about 900-1000ﾟC in spite of increase of microwave power because of the Boudouard reaction. However, the heating rate was faster and final fractional reduction became higher with an increase of the microwave power.