高钛高炉渣在微波场中的加热行为

Heating Behavior of Blast Furnace Slag Bearing High TiO_2 Under Microwave Irradiation

为在高钛高炉渣中引发微裂纹、有效降低其研磨难度,进行了微波加热高钛高炉渣的实验。在引发裂纹的过程中发现其不仅能被微波场有效加热,且有热失控现象发生。为探讨微波加热高钛高炉渣的机理以及产生热失控现象的原因,对不同种类的合成炉渣进行了微波加热实验。实验表明渣中CaTiO3对有效加热高钛高炉渣起到重要作用。利用Network Analyzer测量了其介电常数。测量结果表明CaTiO3的介电常数远远大于一般材料,定量说明了在微波场中CaTiO3对加热高钛高炉渣的作用。此外,实验测得CaTiO3的介电常数随温度的升高而增大,这种正反馈加热方式正是高钛高炉渣在微波场中发生热失控的主要原因之一。

The blast furnace （BF） slag bearing high TiO2 was processed under microwave irradiation in order to induce micro - cracks in it and to improve the grindability of the slag. During inducing crack in the slag, it was found that the slag could be effectively heated by microwave, and thermal runaway was occurred. In order to investigate the mechanism for effectively heating of the slag and the reason of occurring thermal nmaway in the slag irradiated under microwave field, different kind of synthesized slag was heated in microwave field. Experimental results showed that the existence of CaTiO3 played a key role in heating of the slag under microwave irradiation. The pennittivity of CaTiO3 was measured with Network Analyzer. It was determined that the pennittivity of CaTiO3 was higher than general material, which quantitatively explained the role of CaTiO3 on heating of the BF slag bearing high TiO2 irradiated under microwave field. Furthermore, the pennittivity of CaTiO3 increased with the temperature rising, which resulted in the heating way of positive feedback. The heating way of positive feedback was one of the main reasons for the occurrence of thermal runaway in the BF slag beating high TiO2.