What is co and how to pronounce it?

Cobalt (Co), the symbol of elements, ranks 27th in the chemical periodic table. It is a metallic element with a hard and brittle texture.

Its melting point is about 1500℃, boiling point is about 3 100℃, and its relative density is 8.9g/cm? Mohs hardness is 5-5.5. Cobalt has many characteristics, such as high strength at high temperature, low thermal conductivity and strong ferromagnetism.

Cobalt is the transliteration of English cobalt, and the German prototype is Cobalt, which comes from Greek Cobalt and means mine. Its German vocabulary refers to ghosts who are good at pranks. German miners in Saxony use this term to refer to some minerals that can hurt miners' hands and feet. This term is widely used in Europe.

Cobalt is an important raw material for producing heat-resistant alloy, cemented carbide, corrosion-resistant alloy, magnetic alloy and various cobalt salts. About 70% of cobalt consumption is metallic cobalt, which is mainly used in super heat-resistant alloy, tool steel, cemented carbide, magnetic materials and so on. Consumption of compound forms (catalysts, drying materials, reagents, ceramic glazes, etc.). ) About 25%, and the rest is about 5%.

A brief history of research

Cobalt is the transliteration of English cobalt, and the German prototype is Cobalt, which comes from Greek Cobalt and means mine. Its German vocabulary refers to ghosts who are good at pranks. German miners in Saxony use this term to refer to some minerals that can hurt miners' hands and feet. This term is widely used in Europe. This mineral was later found to be poisonous sand.

The chemistry and metallurgy of cobalt may have started in the middle of16th century, but as early as 1450, Egyptians and Babylonians had already used cobalt pigments in pottery. Cobalt salt can dye ceramic glaze blue, and when mixed with compounds of nickel, chromium or manganese, it can prepare various shades from blue to green. In the Yuan Dynasty (13rd century), China also knew how to use cobalt clay minerals as pigments to fire underglaze blue-and-white porcelain.

1735, Swedish chemist Brandt discovered cobalt.

1780, Swedish chemist Bergman studied the properties of cobalt in detail.

/kloc-in the middle of the 0/9th century, cobalt electroplating began to appear on metals.

At the beginning of the 20th century, the application of cobalt in the manufacture of alloy steel and other alloys rose.

19 17, Honda announced the discovery of cobalt-containing permanent magnet alloy.

From 65438 to 0935, permanent magnet alloys developed further, and a series of Al-Ni-Co permanent magnet materials (including Al, Ni, Fe and Co) were derived, and then a new samarium -Co permanent magnet alloy was synthesized. Cobalt has become an important strategic metals.