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What kind of substance is Fe3O4?

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Update time : 2021-11-30 10:26:10
What kind of substance is Fe3O4?
Ferroferric oxide is an inorganic substance with a chemical formula of Fe3O4. It is a magnetic black crystal, so it is also called magnetic iron oxide. It cannot be regarded as "ferrous ferrite" [Fe(FeO2)2], nor can it be regarded as a mixture of ferrous oxide (FeO) and iron oxide (Fe2O3), but it can be regarded as suboxide A compound composed of iron and iron oxide (FeO·Fe2O3). This substance is insoluble in water, alkali solutions, ethanol, ether, and other organic solvents. The natural ferroferric oxide is insoluble in acid solution and is easily oxidized to iron oxide (Fe2O3) in the air in a humid state. Usually used as a pigment and polishing agent, it can also be used to make audiotapes and telecommunications equipment.
What are the physical and chemical properties of ferroferric oxide?
The black Fe3O4 is a mixed-valence oxide of iron. It has a melting point of 1597°C and a density of 5.18g/cm3. It is insoluble in water and soluble in acid solutions. It appears in the form of magnetite in nature. Strong submagnetism and high conductivity.
Ferromagnetic and ferrimagnetic materials undergo a second phase transition above the Curie temperature to transform into paramagnetic materials. The Curie temperature of Fe3O4 is 585℃.
Fe3O4 has high electrical conductivity, and the unusual electrochemical properties of Fe3O4 can be attributed to the transfer of electrons between Fe2+ and Fe3+.
Combustion of iron wire in oxygen will generate ferroferric oxide. Comparing the free energy of Gibbs generated by the standard mole of iron oxide, it is concluded that Fe3O4 has the greatest thermodynamic stability, so the product is Fe3O4.
Iron and air will form oxides on their surface. At this time, the chemical composition of the oxide film itself is not uniform. For example, a piece of low-carbon steel can be covered by three kinds of oxide films: FeO is in contact with the metal, Fe2O3 on the side in contact with air, and Fe3O4 in the middle. More precisely, perhaps a mixture of saturated solid solutions of three oxides constitutes the oxide film on the surface of the steel.
At the same time, the thickness of the oxide film also varies depending on different environmental conditions during oxidation. At room temperature, the thickness of the oxide on the relatively pure iron in dry air does not exceed 20 angstroms (1 angstrom = 0.1 nanometers), but the thickness of the oxide film in moist air increases significantly, and rust spots on the surface can be seen. At this time, the oxide deposition is layered, the side close to the metal is a dense amorphous anhydrous layer, and the side close to the air is a thick porous hydration layer.
Iron reacts with water vapor to produce Fe3O4 and hydrogen.
Fe3O4 has anti-corrosion effects. For example, the bluing of steel parts (also known as blue-burning and baking blue) is to use the oxidation effect of alkaline oxidizing solution to form a blue-black or dark blue Fe3O4film on the surface of steel parts. Used to increase corrosion resistance, gloss, and aesthetics.
How to produce Fe3O4?
There are many ways to prepare ferroferric oxide.
Slow oxidation method of ferrous hydroxide: heating the aqueous solution containing ferrous hydroxide precipitation to above 70°C and performing slow oxidation to obtain fairly uniform regular octahedral or cubic single crystal particles with an edge length of about 0.2μm Of ferroferric oxide powder. Air bubbles can also be used as a means of oxidation. An oxidant like KNO3 can also be used.
Harber method: If you are proficient in operation, you can get ferroferric oxide with a stoichiometric composition of Fe3.00O4.00. In the Harber method, 220g 20% ammonia water is added to a 2.2L FeSO4·7H2O aqueous solution, and it is boiled under the condition of cutting off the air. Round-bottom flask with capillary), add a concentrated aqueous solution containing 25.5g of KNO3 to the boiling.
Alkali addition method: the ferrous sulfate solution is oxidized by adding alkali or the solution of ferrous salt and ferrous salt is mixed in a certain proportion and then alkali precipitation is added.
What is the use of Fe3O4?
Ferroferric oxide is a commonly used chemical material. It has been widely used in building materials, automobile brakes, welding, and other fields, and the market prospect is very broad. In addition, because Fe3O4 has the characteristics of high specific gravity and strong magnetism, it has shown good performance in sewage treatment. Not only that but ferroferric oxide can also be used as a pigment and polishing agent. It can also react with certain chemical substances to achieve anti-oxidation and anti-rust effects. For example, when ferroferric oxide reacts with sodium nitrite, a dense layer of ferroferric oxide can be formed on the surface of the steel to prevent or slow down the corrosion of steel.
Ferroferric oxide Supplier
TRUNNANO(aka. Luoyang Tongrun Nano Technology Co. Ltd.) is a trusted global chemical material supplier & manufacturer with over 12 years of experience in providing super high-quality chemicals and Nanomaterials. Currently, our company has successfully developed a series of materials. The Ferroferric oxide produced by our company has high purity, fine particle size, and impurity content. For the latest price of ferroferric oxide, send us an email or click on the needed products to send an inquiry.
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