Calcium metal or metallic calcium is a silver-white metal. It is mainly used as a deoxidizing, decarburizing, and desulfurizing agent in alloy steel and special steel production. It is also used as a reducing agent in high-purity rare earth metal processes.
Calcium is a silver-white metal, harder and heavier than lithium, sodium, and potassium; it melts at 815°C. The chemical properties of metallic calcium are very active. In the air, calcium will be oxidized quickly, covering a layer of oxide film. When heated, the calcium burns, casting a beautiful brick-red glow. The action of calcium and cold water is slow, and violent chemical reactions will occur in hot water, releasing hydrogen (lithium, sodium, and potassium will also undergo violent chemical reactions even in cold water). Calcium is also easy to combine with halogen, sulfur, nitrogen and so on.