Iron powder dust a collection of particles of iron less than 1 mm in size. The color is black. It is the main raw material for powder metallurgy. According to the particle size, it is customarily divided into five grades of coarse powder, medium powder, fine powder, fine powder and ultrafine powder.
Pure metal iron is silver white, and iron powder is black. This is an optical problem because the iron powder has a small surface area and no fixed geometry, and the crystal structure of the iron block is geometric, so the iron block absorbs a part of visible light. Another part of the visible light is reflected off the mirror to show white; the light that is not absorbed by the iron powder is diffusely reflected, and the visible light that can enter the human eye is less, so it is black.
In food applications, iron powder and ferrous salt are both food antioxidants and food nutrition enhancers. Iron powder is widely added in milk powder. Ferrous salt is widely added in soy sauce, vinegar and fruit juice beverages. The effect is very good. It can not only resist oxidation, but also iron, and prevent iron deficiency anemia.
In industrial applications, iron powder is mainly used to produce powder metallurgy machinery parts. Its main physical properties are bulk density, fluidity, formability, particle shape, etc. These properties are mainly affected by the iron powder production method and its chemical composition.