High Temperature Corrosion of Titanium Under Conditions Relevant to Pressure Leaching: Mass Loss and Electrochemistry

Abstract

The corrosion behavior of titanium was studied using mass loss and electrochemical measurements in sulfuric acid with Cl−, Cu2+, and Fe3+ additions up to 175°C. The corrosion rate of titanium in 30 g L−1 H2SO4 + 12 g L−1 Cl− solution at 150°C measured by mass loss was higher than 62 mm y−1. The corrosion rates of titanium under simulated pressure-leaching conditions determined by both mass loss and polarization resistance measurements were consistent, and also suggest that Cu2+ and Fe3+ ions are excellent corrosion inhibitors for titanium. Results from mass loss and electrochemical measurements all confirmed that the corrosion rate of titanium decreased remarkably with the addition of 1 g L−1 Fe3+ to the leaching solution at 150°C, and that the presence of Fe3+ is the most important factor for the growth of titanium oxide films under pressure-leaching conditions. In addition, iso-corrosion diagrams, with 0.1, 0.5, and 1 mm y−1 lines for titanium in H2SO4 solutions from room temperature to 175°C, were cons...