Iron oxide black, also known as Fe3O4, is an inorganic substance with the chemical formula Fe3O4. It is a black crystal with magnetism, hence it is also known as magnetic iron oxide. It cannot be regarded as "ferrous ferrite" [Fe (FeO2) 2], nor as a mixture of ferrous oxide (FeO) and iron oxide (Fe2O3), but can be approximated as a compound of ferrous oxide and iron oxide (FeO · Fe2O3). This substance is insoluble in water, alkaline solutions, and organic solvents such as ethanol and ether. Natural ferric oxide is insoluble in acidic solutions and easily oxidizes into iron oxide (Fe2O3) in humid air. It is commonly used as a pigment and polishing agent, and can also be used to manufacture audio tapes and telecommunications equipment.

Content: ≥ 90 (%)
Oil absorption: 15-25 (g/100g)
Sieve residue: ≤ 0.5 (%)
Water soluble substance: ≤ 0.5 (%)
Moisture content: ≤ 1.1 (%)
PH value: 5-8
Density: 0.8-1.2 (g/cm ³)
Particle shape: spherical
Color difference: ≤ 1.0
Coloring power: 95-105

Iron tetroxide is a commonly used magnetic material.
Specially made pure iron oxide is used as a raw material for recording tapes and telecommunications equipment.
Natural magnetite is the raw material for iron smelting.
Used for making primer and topcoat.
Iron oxide is the main raw material for producing iron catalysts.
It has a high hardness and can be used as an abrasive. It has been widely used in the field of automotive braking, such as brake pads, brake shoes, etc.
Iron oxide has been recognized in the field of welding materials in China, and its use in the production of welding electrodes and wires is still in its infancy, with a very broad market prospect.
Iron oxide has shown excellent performance in wastewater treatment due to its high specific gravity and strong magnetic properties.
Iron tetroxide can also be used as a pigment and polishing agent.
We can also use certain chemical reactions, such as using sodium nitrite, to generate a dense layer of iron oxide on the surface of steel, which can be used to prevent or slow down the rusting of steel, such as the bluing or blackening of surfaces like firearms and saw blades. Commonly known as' roasted blue '.
Make special electrodes.