Sulfuric acid is the most important mineral acid, which is one of the most widely used of all of the manufactured chemicals. For example, it is used as a dehydrating agent, an absorbent, a catalyst, a reagent in chemical syntheses, and in many other applications.

The use of sulfuric acid can often be an indicator of a nation's industrial activity. The science of sulfuric acid is complicated. Dilute solutions are reducing in nature; oxidizing behavior begins at concentrations of approximately 65% to 70%. The resistance of most engineering metals and alloys used to contain sulfuric acid in the chemical process industries is greatly dependent on acid concentration, the presence of other chemicals, and process temperature.

Zirconium is one of the few metals that resist attack by sulfuric acid at all concentrations to 70% and temperatures to boiling and above. These conditions are so corrosive to metals that most chemical processes are designed to circumvent them. In some cases, however, efficiency of operations and product yields dictate operating parameters that are in this envelope where sulfuric acid is extremely aggressive. The figure below shows the corrosion resistance of zirconium as well as other materials.

This figure gives the design engineer a first cut at material selection. However, most real-life situations do not operate under ideal conditions. Impurities may be present that could exacerbate the corrosion, or temperature/concentration excursions could occur, placing a selected material in jeopardy. The corrosion resistance of nickel molybdenum (Ni-Mo) and Ni-Mo-Cr alloys is impurity sensitive as well as being affected by the temperature and concentration of the sulfuric acid media. Zirconium, on the other hand, can tolerate the presence of some oxidizing impurities, such as ferric, cupric, and nitrate ions, without degradation of its corrosion resistance. In the presence of oxidizing agents, chloride ions must be controlled to limit detrimental attack.

Like most metals, zirconium can tolerate only very small quantities of fluoride ions even at low sulfuric acid concentrations. Fluoride ions can be tied up by using inhibitors, such as zirconium sulfate or sponge.

The ability of zirconium to form a tenaciously adherent, chemically inert oxide film is the primary reason for its excellent corrosion resistance to aggressive media. Oxygen to form this film can come from air, water, carbon dioxide, or carbon monoxide. The film can repair itself in the aforementioned environments with pH in aqueous solutions not entering into the quality of the film produced. In addition to corrosion resistance, this zirconium oxide film is an erosion resistant barrier to entrained solids or catalysts. It also eliminates galling and provides reduced sliding friction. It has a hardness roughly equivalent to sapphire (7.5 on Moh's Scale). The oxide film is readily formed by heating to 1050°F (565°C) for 2 to 4 hours.

Zirconium is used extensively in iron and steel pickling, where sulfuric acid concentrations range from 5% to 40%, with temperatures up to 100°C. Methylmethacrylate producers have found that zirconium is the material of choice in their manufacturing processes using sulfuric acid. Acid recovery systems, butyl alcohol production, and numerous organic synthesis reactions rely on zirconium to contain the corrosive sulfuric acid intrinsic to their processes.