Properties and uses of ferric molybdenum

Molybdenum has an atomic weight of 95.94. The outer electronic structure is 4d5s, the melting point is 2615℃, the boiling point is 4610℃, and the density (20℃) is 10.2g/cm. The binary phase diagram of molybdenum and iron is shown in Figure 1. Molybdenum and iron form two solid solutions α and γ and two intermetallic compounds ε(Fe7Mo6) and σ(FeMo) phases. Industrial ferro molybdenum contains about 60%Mo, melting temperature is 1800 ~ 1900℃; The density is about 9.0g/cm.
The role of molybdenum in steel can be summarized as improving hardenability, improving thermal strength, preventing tempering brittleness, improving remanence and coercivity and corrosion resistance in some media, and preventing pitting tendency. Due to the various beneficial effects of molybdenum in steel, it has been widely used in a series of steel grades such as structural steel, spring steel, bearing steel, tool steel, stainless acid-resistant steel, heat-resistant steel (also known as heat-strong steel), magnetic steel. Molybdenum in cast iron is very effective in improving strength and toughness, when the amount of 0.25% to 1.25%, the casting of medium and large section can also form pearlite matrix structure. Commonly used in rolls and other wear resistant castings.

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Physical and chemical properties of molybdenum

Physical property Molybdenum is located in the mendeleev periodic table of the fifth cycle, the first VIB, as a transition metal element, molybdenum atomic number 42, atomic weight of 95.95, in the atomic electron configuration: 1 s22s22p63s23p64s23d104p64d55s1. Due to the semi-full valence orbital state, molybdenum is in a typical transition state between lithophile elements (8 electron ion configuration) and cuprophilic elements (18 electron ion configuration). Goldschmidt called it siderophile in the geochemical classification of elements. Molybdenum has seven stable natural isotopes. Chemical property Molybdenum is extremely difficult to throw away seven or eight electrons. This determines the chemical properties of molybdenum are relatively stable. At room temperature or at not too high a temperature, molybdenum is stable in air or water. Molybdenum is heated in the air, and the color begins to turn from white (color) to dark gray; When the temperature rises to 520℃, molybdenum begins to be slowly oxidized to form Mo2O3. When the temperature rises above 600℃, molybdenum is rapidly oxidized to MoO3. Molybdenum is heated in water vapor to 700~800 ° C and begins to form MoO2, which is further heated and molybdenum dioxide is continued to be oxidized to molybdenum trioxide. Molybdenum can spontaneously ignite in pure oxygen to form molybdenum trioxide. Molybdenum oxides have been reported a lot, but many are reaction intermediates, rather than thermodynamically stable phase states. There are only nine that are very reliable.

2023

06-26

Molybdenum oxide for operational disposal storage

Operation precautions: closed operation, local exhaust. Operators must be specially trained and strictly abide by the operating procedures. It is recommended that the operator wear a self-priming filter dust mask, chemical safety glasses, protective work clothes, and rubber gloves. Avoid producing dust. Avoid contact with acids. Light loading and unloading during handling to prevent packing damage. Equipped with leak emergency treatment equipment. Empty containers may have harmful residues. Storage precautions: Store in a cool, ventilated warehouse. Keep away from fire and heat. It should be stored separately from acids and edible chemicals, and should not be mixed. Storage areas should be equipped with suitable materials to contain leaks.

2023

06-26

The use of molybdenum oxide

It is mainly used for the determination of protein, phenol, arsenic, lead, bismuth, etc. It can also be used as a reducing agent for phosphorus pentoxide, arsenic trioxide, hydrogen peroxide, phenol and alcohol, and can also be used for the preparation of molybdenum salt and molybdenum alloy. In February 2023, researchers at the National Nanoscience Center constructed a heterostructure of graphene and molybdenum oxide van der Waals materials to realize a new type of electrically regulated photonic transistor.

2023