ArtsAutosBooksBusinessEducationEntertainmentFamilyFashionFoodGamesGenderHealthHolidaysHomeHubPagesPersonal FinancePetsPoliticsReligionSportsTechnologyTravel

Molybdenum a High Temperature Metal: Basic Properties and Applications

Updated on June 19, 2013
M K Paul profile image

After left my software job , I started blogging and entered to this content writing WORLD.I love to write whatever comes to my way....

Source

There is increasing demand of material which is to be used at ultra high temperature. The material which can be used at elevated temperature should have (a) High melting point (b) good mechanical properties at higher temperature (c) good creep and fatigue resistance (d) better oxidation resistance etc. Refractory metals are the obvious choice for this type of applications because of their very high melting point and their strength. Refractory metals include- W, Mo, Nb, Re, Ta. Here, some of the basic properties, production method and different applications of Molybdenum (Mo) will be discussed in brief.

Electron Shell
Electron Shell | Source

The General Properties of Molybdenum Includes:

Atomic No. = 42

Atomic Mass = 96 amu

Melting Point = 2,623 °C (4,753 °F)

8382 °F 4639 °C, Boiling Point = 4912K ,

Density (at 20 °C) = 10.28 g/cc

Specific heat capacity = (25 °C) 24.06 J·mol−1·K−1

Atomic radius = 139 pm

Magnetic property = paramagnetic

Crystal structure = bcc

Source

Production Procedure:

Mo does not occur as the in the free state in nature, instead it is found in the form of minerals principally from molybdenite and Wulfenite. Molybdenum is generally a by-product of copper mining industry. The molybdenite is first heated to a temperature of 700 °C in air which oxidize the sulfide into Mo-Oxide as:

2 MoS2 + 7 O2 → 2 MoO3 + 4 SO2

The oxidized ore is then either heated to 1100 °C to sublimate the oxide, or leached with ammonia which reacts with the molybdenum(VI) oxide to form water-soluble molybdates:

MoO3 + 2 NH4OH → (NH4)2(MoO4) + H2O

Pure molybdenum is produced by the hydrogen reduction of Mo-oxide, while the molybdenum for steel production is reduced by the metallothermy (especially aluminothermic) with addition of iron to produce ferromolybdenum. A common form of ferromolybdenum contains 60% molybdenum. The reduction reaction (aluminothermy ) can be shown as:

MoO3 + Al = Mo + Al2O3

Applications:

There is a widespread use of Mo in various fields ranging from fertiliser to structural material for spacecrafts. It is material for future. There are many active research is going on worldwide on development of high temperature material based on Molybdenum. In nut shell, the main uses for Molybdenum are:

(1) Alloying element in steel: It is used as alloying element in high-strength steels and stainless steels because it readily forms hard, stable carbides.

(2) High temperature and pressure applications in various industries as Aerospace, Zinc processing industries etc. because of its ability to withstand extreme temperatures and high resistance to corrosion.

(3) Pigments and catalyst.

(4) Aircraft parts and industrial motors.

(5) Mo-99 an isotope of Mo is used in various medical test and cure.

(6) Mo-disulfide as used as lubricant and Mo-dislicide as heating element of high temeparture furnace.

(7) Mo powder is used as fertilizer for cauliflower and some other plants.

(8) As an commercially and technologically important Mo alloy-TZM and TZC

Comments

    0 of 8192 characters used
    Post Comment

    • profile image

      WhydThatHappen 5 years ago

      To be honest, I started off very interested in your hub, but when it became all lecture and no application to daily life or demonstrations of its extreme uses- even chemistry books have pictures of things catching on fire and blowing up!

    • M K Paul profile image
      Author

      M K Paul 5 years ago from India

      Actually I write this article for the students who are researching on this field.It is my husband's area of research :)

    Click to Rate This Article