I never knew the demand for Zinc was so high.
Zinc is the fourth-most widely used metal, right behind iron/steel, aluminum, and copper.
Zinc, which has unique abilities to resist corrosion and oxidation, is used for metal galvanization, the process of applying a metal coating to another metal to prevent rust and corrosion. As you can see from the following table, galvanizing metals (particularly steel) is by far the largest application of zinc.