Zinc

Zinc
Zinc is a chemical symbol Zn, its atomic number is 30. Zinc is a blue and white metal. Density of 7.14 grams / cubic centimeter, a melting point of 419.5 ℃. At room temperature, and more brittle; 100 ~ 150 ℃, the variable soft; more than 200 ℃, they become brittle. Chemical properties of zinc and lively, the air at room temperature, the thin surface layer of basic zinc carbonate dense membrane, can prevent further oxidation. When the temperature reached 225 ℃, the zinc oxide heated. Burning issue blue-green flame. Zinc soluble in acid, but also easy replacement from the solution of gold, silver, copper and so on. Zinc oxide film of high melting point, but the metal zinc has a low melting point, so light on alcohol heating zinc tablets, zinc tablets melting soft, but not fall, because the role of the oxide film. Zinc is the fourth common metals, second only to iron, aluminum and copper.
1) based on zinc content of different established.
0 # zinc ingots 99.995%. 1 # zinc ingots and 99.99%.
(2) futures contracts for delivery of standard products: zinc ingots, in line with national standard GB470-1997 standards ZN99.995 provisions of the zinc content of not less than 99.995%.