辅助电极型硅传感器的热力学分析与实验

Thermodynamic analysis and experiment of auxiliary electrode silicon sensor

首次用热力学分析了硅传感器的辅助电极与熔液中硅、氧和碳的反应方向与限度。讨论了局域)与熔液中硅活度(a[Si])的相关性;揭示了前人用辅助电极型硅传感器对高碳熔液测量平衡氧逸度(fO2时可能发生附反应,指出了有效测量范围;发现了Mg2SiO4(s)+MgO(s.s.)硅传感器存在测量盲区。研制了一种新Mg2SiO4(s)+MgO(s)硅传感器,用Mg2SiO4(s)+MgO(s)硅传感器测得了盲区内高碳低硅熔液中硅的活度,实验表明该测量无附反应发生,证明了热力学分析是可信的。

The direction and limitation of reaction between auxiliary electrode of all kinds of silicon sensor and ,, in melt are analyzed with thermodynamic method for the first time. The correlation of equilibrium fugacity fO2 and activity a of local reaction in melt is discussed.It is found that side reaction would occur when measuring high carbon melt with the auxiliary electrode silicon sensor,which was usually used by predecessor.The effective measuring ranges of melt components are figured out.The measuring blind zone of Mg2SiO4(s)+MgO(s.s.) silicon sensor is found through theoretical analysis. A new developed silicon sensor with Mg2SiO4(s)+MgO(s) auxiliary electrode is used measuring silicon activity in high carbon low silicon melt which is in the blind zone of Mg2SiO4(s)+MgO(s) silicon sensor before.It is testified that there is no side reaction with this novel silicon sensor and the thermodynamic analysis is correct.