A novel electrochemical sensor for phosphorus determination in the high phosphorus liquid iron

A novel phosphorus sensor based on the bilayer structure of ZrO2(MgO)/CaAl1.64O3.46 was fabricated and tested in high phosphorus liquid iron in this work, where the 4CaO∙P2O5 used as the auxiliary electrode was synthesized in situ by the CaAl1.64O3.46 layer during the measurement. The results indicated that phosphorus sensor showed fairly good reproducibility and sensibility to phosphorus content in high phosphorus liquid iron and the empirical equation was obtained. The application conditions of this phosphorus sensor were that the relationship between a[P] and a[O] should be satisfied to be lna[P]2a[O]5≥−29.30 at 1773 K and lna[P]2a[O]5≥−26.40 at 1823 K. After the measurement, the 4CaO∙P2O5 was detected in the CaAl1.64O3.46 layer and further confirmed that the auxiliary electrode had been formed in situ in the liquid iron. This work would be beneficial to online detecting the phosphorus content in the dephosphorization process of high phosphorus liquid iron and then improve production efficiency.