Highly Active and Efficient Hybrid Sacrificial Anodes Based on High P Pig Iron, Zn and Mg

Abstract

The work discusses the development of novel hybrid sacrificial anodes based on high phosphorus pig iron (HPPI), Zn and Mg with stoichiometry xP-y(Mg0.25Zn0.75) (x = 1.5, 3.5, 8.0 wt% of phosphorus (P) in the pig iron and y = 10, 20, 30 wt%). Mg results in highly active corrosion potentials (∼−1.0 V with respect to saturated calomel electrode) of the high P content sintered 8.0P-y(Mg0.25Zn0.75) as compared to the low P content sintered (1.5 P and 3.5 P)-y(Mg0.25Zn0.75) in 3.5%NaCl solution and artificial seawater. The formation of active MgZn2 after sintering and preferential dissolution of Mg in the 8P-y(Mg0.25Zn0.75) attribute to greater active behavior. The anodes show high anode capacity (∼773 to 815 Ah Kg−1) and efficiency (∼80 to 85%).