Effect of Ferric Ion on Corrosion Resistance of Zirconium in HC1-A1C3 Environment

摘要

In order to evaluate the corrosion resistance of zirconium in mineral extraction processes, such as clay-hydrochloric acid leaching process for extracting alumina, the Bureau of Mines conducted corrosion studies in HCl-AlCl3-FeCl3, environments. A series of weight loss and electrochemical tests were conducted at 25 and 65C in aluminum chloride (AlCl3) plus hydrochloric acid (HCl) solutions containing 0 to 1,000 ppm ferric ion. It was determined that zirconium, which normally exists in a passive state in chloride-containing solutions, undergoes pitting attack in solutions containing more than 100 ppm of ferric ion. It is also shown that an oxide film prepared in air at high temperature offers protection in acid solutions containing levels of ferric ion from 300 to 1,000 ppm.