Abstract:

Corrosion products on iron ware from “Huaguang Reef Ⅰ” and the removal of harmful salts were investigated.The surface resistivity of the rust on one iron ware named HTQ6^# was （3×10³）—（1×10⁸） Ω, and the rust was completely mineralized.The rust including Fe₃O₄, α-FeOOH, γ-FeOOH and FeOCl was magnetic.In order to avoid the damage of the harmful rust including γ-FeOOH and FeOCl on the original appearance of the cultural relics, desalination process using constant current density of -0.5 mA·cm^-2 in 2.5% NaOH solution was studied.The results were shown as follows.The proportion of chloride ion removed was 53.31%, which was higher than that by using impulsive current, at the final time of desalination for 264 h.Meanwhile, the concentration of chloride ion in the solution was 6.1 mg·L^-1 and electrical efficiency was 1.95%.In this process, the amount of chloride ion in the iron matrix decreased from 2.03% to 0.95% at applied potential of -2.25—-1.61 V with the potential stabilized at -1.61 V.