Limestone, Calcium Carbonate, CaCO3, is basically inert, non reactive. Lime, CaO, Calcium Oxide, usually made from Limestone, is reactive, a base, when hydrated,(water added), becomes CaOH, Calcium Hydroxide, which can be corrosive. It takes heat, usually in a commercial rotary kiln, to produce Lime.
Most galvanized coating, is zinc plated on metal/steel tubing. Galvanize is to inhibit rust, though galvanize can be removed mechanically, wheel-ware on track, and abrasive cleaning, to polish track, for better electrical conductivity.
