Chromium was discovered by the French chemist Nicholas Louis Vauquelin at Paris in1798. He was intrigued by a bright red mineral that had been discovered in a Siberian gold mine in 1766 and was referred to as Siberian red lead.
Vauquelin analysed it and confirmed that it was a lead mineral. Then he dissolved it in acid, precipitated the lead, filtered this off, and focused his attention on the remaining liquor from which he succeeded in isolating chromium. Intrigued by the range of colours that it could produce in solution, the name chromium comes from the Greek "chroma" and means color. He then discovered that the green colouration of emeralds was also due to chromium. It is now known as crocoite and is a form of lead chromate.
The color of chromium is a lightweight blue-silvery white. Due to its very high corrosion resistance against many different acids and bases as well as hot gases, chromium is used for all types of protective coating as a popular material.
It is used in combustion equipment as a wear-resistant coating to increase the service life of specific components. As a component in high-temperature fuel cells, our chromium also performs brilliantly.
Given its unique properties, alongside these applications, chromium is also used as a brilliant decorative coating for operating elements on appliances and jewellery. Chromium is used for some very special industrial applications, for example as a coating material in a variety of processes.
As a chromium nitride hard material coating applied to moving parts, chromium provides reliable protection against wear and abrasion. In addition, it gives brilliance and sheen to watches and fittings of all types. At the same time, chromium protects against corrosion.
Chromium is most commonly produced using the aluminothermal process which is based on the principle of reducing chromium oxide with aluminum. In this process, chromium oxide is mixed with aluminum powder and the mix is then ignited. The reduction process then continues on its own as an exothermal reaction without the need for any further supply of energy. A chromium content of up to 99.8 % is possible depending on the purity of the initial powder. The main impurities are aluminum, iron, silicon and sulfur. The exothermal reaction involved in chromium oxide reduction.
We can obtain exceptionally pure chromium by using the electrolytic process. Using this process, purities of up to 99.995 % are possible. This is achieved by dissolving CrO3 Cr(VI) in sulfuric acid, we can obtain chromium flakes by using a galvanic deposition process. However, it is not used in all countries because this process comes at a significant environmental cost.