Chromium: The Element

Chromium is a very useful chemical element. Atomic symbol of chromium is Cr and its atomic number is 24. This element was discovered in 1797, by French pharmacist and chemist Louis Nicolas Vauquelin. He discovered chromium in the mineral crocoite (lead chromate). Chromium has derived its name from Greek word 'Chroma' which means color. Such a name has been given to the element because the chromium compounds are found in various colors. Chromium is obtained from its ore, called chromite. This ore is mainly available in countries like Iran, Turkey, New Zealand, Zimbabwe, Russia, Finland etc. Chromium can be produced in a large scale by reduction of chromium oxide with aluminum.

Properties of Chromium

Chromium is a hard metal, lustrous and steely-gray in color. Both boiling point and melting point of chromium are quite high. It is a tasteless and odorless substance. It possess malleable properties, that is, it can be shaped, bent or drawn out. Chromium has high resistance towards corrosion. Chromium undergoes only a moderate thermal expansion.

Uses of Chromium

Chromium is used in the production of stainless steel. It helps to harden the steel, make it corrosion resistant and prevent its discoloration. Apart from steel, it is also used for making many other useful alloys. It is also used in electroplating of metals which gives a hard, beautiful surface to the metals and prevent them from corrosion. Chromium acts as a catalyst in various chemical reactions. When added to glass, it adds an emerald green color to glass. Owing to the stable crystalline structure and corrosion resistant characteristics, chromite is used for the formation of bricks and shapes in the refractory industry.

Uses of Chromium Compounds

The distinct feature of all chromium compounds is that all are colored. Sodium dichromate, potassium dichromate, potassium and chrome alums are some of the most useful compounds of chromium. Both the dichromates are used in quantitative analysis as oxidizing agents. In leather industry, they help in the tanning process. Lead chromate has a high value as a pigment. In textile industry, chromium compounds acts as mordants and facilitate in the dyeing process. Some other industries like aircraft manufacturing use chromium for the purpose of anodizing aluminum. Chromium is required in human body in trace amount for sugar and lipid metabolism. Inadequate amount of chromium in the body can lead to an illness called chromium deficiency.

Chromium is a toxic substance and also possess carcinogenic properties. So it should be handled carefully with proper safety measures. In case any chromium production unit is abandoned, proper clean up of the site is necessary to prevent environment pollution.