摘要
炼铁高炉热状况控制和低硅铁冶炼、铁水炉外脱磷及某些稀有元素回收等工艺都要求能够快速确定铁水中的硅含量，而传统的化学和光谱分析法不能满足这一要求。本专题用一种测头能直接、迅速、准确地测量铁水中的硅含量。这种硅测头是用ＭｇＯ稳定的ＺｒＯ２作固体电解质，ＺｒＯ２＋ＺｒＳｉＯ４为辅助电极制成的，测头电池表达式为：Ｍｏ－ＺｒＯ_｜〔Ｓｉ〕Ｆｅ｜ＺｒＯ_２＋ＺｒＳｉＯ_４｜ＺｒＯ_２（ＭｇＯ）｜Ｍｏ＋ＭｏＯ_２｜Ｍｏ在实验室中，用这种测头进行了各种条件下的硅含量测试，它能在１０ｓ内测出硅电动势，且具有较高的分辨率。测试电动势与理论值十分相近，说明这种测头可靠。用到工厂高炉炉前测试高硅铁水中硅，大部分测试成功；在低硅铁水中，正常操作时，３～５ｓ就能得到稳定的硅电动势，硅含量测定值与分析值偏差小于０．１ｗｔ％，测试成功率可达９０％以上。此类测头能满足工业要求，可投入实际应用。
Rapid determination of silicon content in hot metal is required for the control of thermal state of blast furnace,the low silicon iron-smelting,external removal of phosphorus from hot metal and the recovery of certain rare elements.Since the conventional methods such as chemical and spectrographic analysis cannot do that,researches have been carried out for a new type sensor in order to directly and rapidly determine silicon contents in hot metal.This silicon sensor which incorporates magnesia-stabilized zirconia as solid electrolyte and a mixture of ZrO_2+ZrSiO_4 as auxiliary electrode has been made in laboratory at high temperature.The cell expression of the sensor is:Mo-ZrO_2|[Si]Fe|ZrO_2+ZrSiO_4|ZrO_2(MgO)|Mo+MoO_2|Mo In laboratory,this sensor has been applied to measure silicon contents under various conditions.The sensor is of considerable resolution,and can determine silicon electromotive force within 10s.The measured values and the theoretical ones of electromotive force are very close,that is to say,the sensor is reliable.When the sensor applied to commercial blast furnaces,the results on-the-spot measured exhibit that most of the data are satisfied for high silicon hot metal.In low silicon hot metal,while in normal operation,stable silicon electromotive force can be obtained within 3～5s and the deviation between the measured value and theoretical one of silicon content is less than 0.1%(weight) with success ratio more than 90%.This type of sensor can meet the requirements for industrial production and be applied in practice.
关键词
硅测头
炼铁
铁水
硅活度
测定
Silicon sensor Auxiliary electrode Electrochemical sensor Silicon activity in hot metal
