Zinc is a hard, silvery metal belonging to the nonferrous metal group. In nature zinc rarely occurs as a free element. It is widely distributed in compounds, such as franklinite, a zinc-iron manganese mineral; willemite, a zinc silicate; and zincite, a zinc oxide.
After segregation of the mineral into concentrates, the ore goes to the smelters where the distillation, or retort, method is used. After being roasted and reduced in a retort furnace, the metallic zinc is then boiled to a vapor and condensed as pure zinc. For high grade zinc, the electrolytic method of refinement is used.
Since zinc melts easily and does not rust, it is used for galvanizing steel and iron products, such as buckets, wires, and pipes. It is a main alloying constituent of brass. Zinc (symbol Zn) has atomic number 30. Its atomic weight is 65.37 (65.38, O = 16). It has a density of 7.14 gm/cc and a melting point of 419 °C.
