Tantalum and tantalum alloy is one of the few metal materials that can withstand the full concentration of sulfuric acid.
Among metals, the sulfuric acid corrosion resistance of tantalum and tantalum alloy is second only to that of some precious metals: iridium, ruthenium, gold, osmium, platinum, and high silicon cast iron containing 17% silicon >. They were ranked by corrosion resistance to sulfuric acid: iridium = ruthenium > gold > osmium > high silicon cast iron > platinum > tantalum.
Among tantalum alloys used in sulfuric acid, the most common is tantalum tungsten alloy ta-2.5w. The corrosion resistance of this alloy in sulfuric acid and hydrochloric acid is better than that of pure tantalum.
1. Sulfuric acid corrosion limit of tantalum: <70% sulfuric acid: 260 degrees, 70%-96% sulfuric acid :200 degrees, 98% sulfuric acid: 150 degrees, fuming sulfuric acid: not applicable.
2. Sulfuric acid corrosion limit of tantalum tungsten alloy: : <70% sulfuric acid: 260 degrees, 70%-96% sulfuric acid :230 degrees, 98% sulfuric acid: 175 degrees, fuming sulfuric acid: not applicable.
3. Tantalum alloy containing a small amount of platinum or ruthenium has better corrosion resistance than the above two materials. It can be used to 250 degrees in 96% of sulfuric acid and is not easy to occur hydrogen embrittlement.
4. If a small amount of nitric acid or nitrogen oxide is added to sulfuric acid, it can act as a corrosion inhibitor.
