Pure Molybdenum Production

In molybdenite processing, the molybdenite is first heated to a temperature of 700 °C (1,292 °F) and the sulfide is oxidized into molybdenum(VI) oxide by air: 2 MoS2 + 7 O2 → 2 MoO3 + 4 SO2  The oxidized ore is then either heated to 1,100 °C (2,010 °F) 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.

Molybdenum Powder

Copper, an impurity in molybdenite, is less soluble in ammonia. To completely remove it from the solution, it is precipitated with hydrogen sulfide. Pure molybdenum is produced by reduction of the oxide with hydrogen.

While the molybdenum for steel production is reduced by the aluminothermic reaction with addition of iron to produce ferromolybdenum. A common form of ferromolybdenum contains 60% molybdenum.

Pure Molybdenum and Molybdenum Alloy

Well, today, I get a good artical from the book which mainly introduce the differences between pure molybdenum, TZM alloy(titanium-zirconium-molybdenum), MHC alloy(molybdenum-hafnium-carbon), MLa alloy(molybdenum-lanthanum-alloy), MY alloy(molybdenum-yttrium-alloy), MW alloy(molybdenum-tungsten-alloy), MCu alloy(molybdenum-copper-alloy) in its content, properties and applications. By reading, I have a better understanding in their about them. Here, I am glad to share it with you.

Content:

Name	Ingredients (%)
	W	Ti	Zr	C	La2O3	Y2O3	Hf	Cu
Mo
TZM		0.40~0.55	0.06~0.12	0.01~0.04		0.08~0.14
MHC				0.04~0.12
ML					0.2~3.0
MY						0.2~0.8
MW	20~50
MCu								0.3~30.0

Properties:

1. Pure Molybdenum Properties:

High melting point and high elastic modulus;

Low and resistor and vapor pressure;

Good heat resistance, thermal conductivity and thermal expansion coefficient

2. TZM　Alloy(Titanium-Zirconium-Molybdenum)

Compared with pure molybdenum, TZM  alloy has following advantages:

Better heat resistance;

Higher recrystallization temperature;

Good creep resistance and weldability

3. MHC Alloy(Molybdenum-Hafnium-Carbon)

MHC alloy has the following advantages  which compared with TZM alloy :

Better creep resistance;

Higher heat resistance and recrystallization temperature

4.MLa Alloy(Molybdenum-Llanthanum)

MLa alloy compared with pure molybdenum has the following advantages:

Better creep resistance and welding performance;

Higher recrystallization temperature;

Good plasticity after high temperature used

5.  MY Alloy(Molybdenum-Yttrium)

MY alloy compared with pure molybdenum has the following advantages:

Better oxidation resistance;

Higher recrystallization temperature;

Good weldability;

Good adhesion with glass sealing

6.MW Alloy(Molybdenum-Tungsten)

MW alloy compared to pure molybdenum alloy has the following advantages:

Good resistance to molten metal corrosion resistance;

Higher recrystallization temperature and strength

7.MCu Alloy(Molybdenum-Copper)

MCu alloy has the following advantages:

Good thermal conductivity and thermal expansion

Applications:

Name	Nominal Composition (wt%)	Applications
Pure Molybdenum	99.95Mo	Vacuum furnaces, glass melting, electronic devices, heat sink
TZM	0.5Ti, O.08Zr, 0.03C	Thermal processing tools, stoves installed appliances
MHC	1 ~ 1.5Hf, 0.03 ~ 0.05C	Hot work tool
Mo-W	10 ~ 30W	Molten zinc treatment, sputtering target
Mo-Re	41 ~ 47.5Re	Traveling wave tubes, rocket boosters
Mo-La	0.5-1.5La (La2O3 state was near)	Sintering boat