Molybdenum Market Overview of Current & Future Supply

Molybdenum: Uses

Prabhash Gokarn Head M&BD, Tata Steel Molybdenum Presentation

Uses of Molybdenum


Molybdenum In Stainless Steel


Why Molybdenum Stainless Steels
Molybdenum Increases Stainless Steel Pitting Resistance

Pitting Resistance Equivalent Number (PREN) is a measure of the relative pitting
corrosion resistance of stainless steel in a chloride-containing environment. Higher
PREN values indicate greater corrosion resistance.

The formula for PREN is:
PREN = %Cr + 3.3*%Mo + 16*%N

This formula suggests that molybdenum is 3.3 times more effective than chromium at
improving pitting resistance, which is true within limits. Chromium must always be
present in stainless steel to provide basic corrosion resistance. Molybdenum
cannot provide this basic resistance, but it significantly enhances a stainless steel's
corrosion resistance, as the formula shows


Why Molybdenum Stainless Steels

Comparison of PREN values for different ferritic, austenitic and duplex stainless steels


Metallurgy of Mo in Stainless Steel
Molybdenum adds corrosion resistance and high temperature strength.

Corrosion Resistance
Molybdenum primarily increases the corrosion resistance of stainless steels.
Molybdenum containing stainless steels are thus used in applications that are more
corrosive, such as chemical processing plants or in marine applications.

Elevated Temperature Strength
As a large atom, molybdenum increases the elevated temperature strength of
stainless steels through solid solution hardening. Mo Stainless steels are used in
heat exchangers and other elevated temperature equipment such as in automotive
exhaust systems.


Metallurgy of Mo in Stainless Steel
Molybdenum is a ferrite former

Thus when molybdenum is added to improve the corrosion resistance of an
austenitic stainless steel, there has to be an austenite former such as nickel or
nitrogen added in order to keep the structure austenitic.

Duplex stainless steels have a mixture of austenitic and ferritic grains in their
microstructure; hence they have a “duplex” structure. This effect is achieved by
adding less nickel than would be necessary for making a fully austenitic stainless
steel.

In austenitic stainless steels between two and seven percent are added, in duplex
stainless steels, between three and five percent. The addition of one or two percent
molybdenum to ferritic stainless steels also significantly increases the corrosion
resistance and the elevated temperature strength of these stainless steels.


Molybdenum Stainless Steels
Common ferritic, austenitic and duplex stainless steels
AISI Cr Mo Ni N PREN
Ferritic grades
409 11.5 11.5
430 16.5 16.5
434 16.5 1 19.8
436 17.5 1.25 21.6
444 17.7 2.1 24.6
Austenitic grades
304 18.1 8.3 18.1
316 17.2 2.1 10.2 24.1
317L 18.2 3.1 13.7 28.4
317LMN 17.8 4.1 12.7 0.14 33.6
904L 20 4.3 25 34.2
(6%Mo) 20 6.1 18-24 0.2 43.3
Duplex grades
2304 23 0.3 4.8 0.1 25.6
2205 22 3.1 5.7 0.17 35.0
2507 25 4 7 0.27 42.5

Molybdenum In Alloy Steel & Cast Irons


Molybdenum In Alloy Steel & Cast Irons
Molybdenum in alloy steel & cast iron improves :
• hardenability
• reduce temper embrittlement
• resist hydrogen attack & sulphide stress cracking
• increase elevated temperature strength
• improve weldability, especially in high strength low alloy steels (HSLA)

End uses of Moly containing alloy steels and cast irons include :
• Automotive, shipbuilding, aircraft and aerospace
• Drilling, mining, processing
• Energy generation, including boilers, steam turbines and electricity generators
• Vessels, tanks, heat exchangers
• Chemical & Petrochemical processing Typical % Mo content
• Offshore; Oil Country Tubular Goods (OCTG) Heat Treatable Engineering Steel 0.25 - 0.5
Case Hardened Steel 0.15 - 0.5
High Temperature Steel 0.3 - 1.2
Oil Country Tubular Goods (OCTG) 0.3 - 1.0
HSLA Steel 0.15 - 0.25
Maraging Steels 4.0 - 5.0
Tool & High Speed Steel 0.5 - 9.0
Cast Iron 1.0 -3.0


Metallurgy of Mo in Alloy Steel & Iron
The classic methods of strengthening low alloy steels are
• solution hardening
• quenching and tempering
• precipitation hardening
• controlled rolling
Molybdenum is an effective strengthener in all cases. The large majority of low alloy
steels are quenched and tempered.

Mo helps reduce Hydrogen embrittlement and sulphide stress cracking through solid
solution strengthening and the formation of complex carbides together with other
elements such as chromium and niobium.

The capability of molybdenum to provide resistance
to sulphide stress cracking has been the key to the
development of a broad range of steel grades used for
Oil Country Tubular Goods and in chemical and
petrochemical plants.


Heat Treatable Engineering Mo - Steel
Demand of higher strength and toughness require increasing alloy content for improved
hardenability by increasing :
•Carbon content ( 0.22% to 0.55%)
•1% Cr and 1% Cr / 0.25% Mo grades C from 0.25% to 0.55%.
•Higher stressed components CrNiMo steels Ni, Cr: 1% and 2% and Mo 0.25%
•Thru hardening steels (generator shafts etc) : NiCrMo steels Ni upto 4% and Mo upto 0.7%
• CrMoV steels for good weldability or extra high toughness. C partly replaced by 0.9% Mo
Molybdenum’s most important role in these grades is to increase the hardenability and to
promote a uniformly hardened microstructure across the full cross section.
Application include:
• Automotive parts such as crankshafts, axle shafts, steering components,
• Shafts in locomotive construction, shipbuilding and heavy engines
• Parts for machine tools and general mechanical engineering
• Turbine and generator shafts in power stations
• Components and accessories for the oil and gas industry
• Fastening elements such as high strength bolts
• Landing gear and control elements in aviation
• Tools in oil and gas exploration

Heat Treatable Engineering Mo - Steel
GRADE C Cr Ni Mo APPLICATION
1% Cr and CrMo Steel
28Cr4 0.25 1 Driving wheels and shafts
25CrMo4 0.25 1 0.25 Axle arbors, turbine components
34Cr4 Popular Tata 0.34 1 Axle, axle arms
34CrMo4 Steel Grade 0.34 1 0.25 High toughness components, incl. crank shafts, axle arbors
41Cr4 upto ‘99 0.41 1 Axles, control components
42CrMo4 0.41 1 0.25 High toughness components for automobiles and aircraft
48CrMo4 0.5 1 0.25 Steel for induction hardening up to 250 mm Diameter
50CrMo4 0.5 1 0.25 High toughness components for automobiles and aircraft
CrNiMo Steel
36CrNiMo4 0.36 1 1 0.25 Highly charged components for automobiles and aircraft
34CrNiMo6 0.34 1.5 1.5 0.25 Crank shafts, eccentric shafts, gear components
30CrNiMo8 0.3 2 2 0.4 Structural components for heavy demands
NiCrMo Steel
28NiCrMo4 0.28 1 1 0.25 Structural components for very heavy demands
33NiCrMoV14-5 0.33 1.3 3.5 0.5 Generator shafts, high strengt & toughness components
36NiCrMo16 0.36 1.8 4 0.7 High strength mechanical engineering components
CrMoV Steel
14CrMoV6-9 0.14 1.5 0.9 High strength welded components
30CrMoV9 0.3 2.25 0.25 High toughness crank shafts, screws, bolts
All grades with Mn between 0.5 and 0.9%


See Annexure For More On Molybdenum
Applications


Molybdenum Mines - Regions


Back Up : Stainless Steel Properties


Stainless Steel Properties
Select properties of austenitic and ferritic stainless steels
Properties Austenitic Ferritic
Toughness Very high Moderate
Ductility Very high Moderate
Weldability Good Limited
Thermal expansion High Moderate
Stress corrosion cracking resistance Low Very high
Magnetic properties Non-magnetic Ferro magnetic


Stainless Steel Properties
Ferrite formers Austenite formers
Iron Nickel
Chromium Nitrogen
Molybdenum Carbon
Silicon Manganese
Copper


Duplex Stainless Steel
Duplex stainless steels are called “duplex” because they have a two-phase microstructure consisting of grains of
ferritic and austenitic stainless steel. The duplex structure gives this family of stainless steels a combination of
attractive properties:

Strength: Duplex stainless steels are about twice as strong as regular austenitic or ferritic stainless steels.

Toughness & Ductility: Duplex stainless steels have significantly better toughness and ductility than ferritic
grades; however, they do not reach the excellent values of austenitic grades.

Corrosion Resistance: For chloride pitting and crevice corrosion resistance, their chromium, molybdenum and
nitrogen content are most important. Duplex stainless steel grades have a range of corrosion resistance, similar
to the range for austenitic stainless steels, i.e from Type 304 or 316 (e.g. LDX 2101©) to 6% molybdenum (e.g.
SAF 2507©) stainless steels.


Duplex Stainless Steel
Stress corrosion cracking resistance: Duplex stainless steels show very good stress corrosion cracking (SCC)
resistance, a property they have “inherited” from the ferritic side. SCC can be a problem under certain
circumstances (chlorides, humidity, elevated temperature) for standard austenitics such as Types 304 and 316.

Cost: Duplex stainless steels have lower nickel and molybdenum contents than their austenitic counterparts of
similar corrosion resistance. Due to the lower alloying content, duplex stainless steels can be lower in cost,
especially in times of high alloy surcharges. Additionally, it may often be possible to reduce the section thickness
of duplex stainless steel, due to its increased yield strength compared to austenitic stainless steel. The
combination can lead to significant cost and weight savings compared to a solution in austenitic stainless steels.

Molybdenum improves pitting and crevice corrosion resistance, which is particularly helpful in preventing salt and
corrosive pollution damage.


Alloy Steels – Case Hardening Mo Steels
Case hardening Steel
Tough core and a hard case are the target properties of components made of case hardened steel. That
combination of wear resistance and fatigue strength in the surface and impact strength in the core zone is
achieved by carburizing the surface layer of the component, which is subsequently quenched and tempered.
Components produced that way with optimized properties between core and case include gear components of all
kind, camshafts, cardan joints, driving pinions, link components, axles and arbors.
Applications include:
Transportation: Case hardened components are needed in any engine driven vehicle, whether it's a small car, a
race car, a truck or an ocean vessel.
Energy generation: Gear wheels and components in large dimensions have to withstand both stress and wear in
equipment such as hydroelectric power stations, wind turbine generators, propeller drives of drilling rigs or steam
turbine gears of power stations.
General mechanical engineering: forging presses, steel rolling equipment, machine tools; drivelines of mining
equipment and heavy duty transmissions; earth moving equipment and heavy duty construction cranes. The
combination of wear resiastance and fatigue strength is always a key characteristic of the case hardened steels
used for these applications.
For carburisation the steel is heated in a carbon releasing medium to a temperature where the base material is completely
transformed into austenite (here the solubility for carbon is much higher than in the ferritic structure). This way the surface layer is
carburised up to 0.7% carbon, while the carbon content of the core material is limited to about 0.25%. Quenching and tempering
following the carburisation produces a high carbon martensitic structure near the surface, with great hardness and wear
resistance, while the core retains its original strength and toughness properties.


Case hardening Steel
Molybdenum (0.15 - 0.50%) is used in carburising steels to simultaneously increase the hardenability of the low
carbon core and toughen the high carbon case. It is especially effective in large cross sections, such as in gears.
Molybdenum is not oxidised during carburisation, making it an effective hardening agent which does not cause
increased surface cracking and spalling.
Standard case hardening Steels
SAE % Alloy content
DIN - EN
/ASTM C Cr Mo Other
MnCr Steel
20MnCr5 5120 0.2 1.2 1.3 Mn
CrMo Steel
20MoCr4 0.2 0.4 0.5
20CrMo5 8620 0.2 1.2 0.25
NiCrMo Steel
20NiCrMo2-2 0.2 0.5 0.25 0.5 Ni
18CrNiMo7-6 0.18 1.7 0.3 1.5 Ni


High Temperature Steel
Molybdenum has been the key element to develop ferritic steels with good creep strength for service
temperatures up to 530 °C.

Products and components made of high temperature steels include
• seamless tubes for water boilers and superheaters, boiler drums,collectors, pumps and pressure vessels for
elevated temperature service
• heavy steam turbine shafts with the diameter exceeding 2 meters, weighing more than
100 mt.
•Molybdenum in solid solution is very efficient in reducing the creep rate of steel at elevated temperatures.
Molybdenum slows the coagulation of carbides during high temperature service. The best results in terms of
elevated temperature strength are obtained in quenched and tempered condition with an upper bainitic
microstructure.
•The family of Mo, CrMo and CrMoV steels continues to be the materials of choice for the worldwide installations
of power plants, oil refineries and petrochemical plants

In recent years, worldwide efforts to increase efficiency in power plants have created a demand for steels that can
withstand higher pressure and higher service temperatures. A promising development is grade P/T91 –
X10CrMoVNb9-1, which is a modification of the existing 9% Cr 1% Mo grade with additions of vanadium and
niobium


Mo Steels – Oil Country Tubular Goods
(OCTG)
OCTG include three types of seamless tubes, delivered in quenched and tempered condition:
•Drill pipe – heavy seamless tubes that rotate the drill bit and circulate the drilling fluid. Joints of pipe 30 ft (9m)
long are coupled together with tool joints
•Casing pipe is used to line the hole.
•Tubing – a pipe through which the oil or gas is produced from the wellbore. Tubing joints are generally around
30 ft [9 m] long with a thread connection on each end.
Traditionally the grades used for for OCTG applications were carbon manganese steels (up to the 55 ksi strength
level) or Mo containing grades up to 0.4% Mo.
In recent years deep well drilling and reservoirs with contaminants causing corrosive attack have created strong
demand for higher strength materials resistant to hydrogen embrittlement and sulphide stress cracking (SCC).

Highly tempered martensite has been identified as the structure which is most resistant to SCC at higher strength
levels, and 0.75% has been found to be the Mo concentration to obtain the optimum combination of yield strength
and resistance to SCC (1).
This is reflected in the list of Mo containing low alloy API standard grades. For the 75 ksi strength level 0.4% Mo is
sufficient, while each of the the higher strength grades up to 125 ksi show the optimum Mo level of 0.75 or 0.80 %
For higher strength up to 140 ksi (yield strength 965-1171 MPa) dispersion has been introduced as an additional
strengthening mechanism by the addition of niobium. A non API specialized grade with 0.05% niobium; the
molybdenum range is extended to 1.1% is used. For service in oil and gas fields with more aggressive corrosion
environments stainless API grades are standardized with 9% Cr, 1% Mo and 13% Cr (without Mo). However, the
2% Mo grade can be used in lower pH and higher H2S environments.

Mo Steels – Oil Country Tubular Goods
(OCTG)
Country Tubular Good (OTCG) Steel Grades
Low Alloy Grades
Yield strength API Yield Strength Tensile Strength
% Alloy content
(ksi) Grade (0,2% proof stress) min (N/mm2)
Code C Mn Ni Cr Mo Cu (N/mm2)
40 H40 0.5 1.5 276-552 410
55 K55 0.5 1.5 379~552 655
75 C75-1 0.5 1.7 0.5 0.5 0.4 0.5 517~620 665
90 C90-1 0.35 1.9 0.9 1.2 0.75 620~724 690
95 T95-1 0.35 1.2 0.9 1.5 0.85 655~758 724
125 Q125 0.35 1 0.9 1.2 0.75 860~1035 930
140 0.3 1 1.6 1.1 0.05 965~1171 1034

Country Tubular Good (OTCG) Steel Grades
Stainless Steels
Yield strength API Yield Strength Tensile Strength
% Alloy content
(ksi) Grade (0,2% proof stress) min (N/mm2)
Code C Mn Ni Cr Mo Cu (N/mm2)
9% Chromium Stainless
75 C75-9Cr 0.15 0.6 0.5 9 1 0.25 517~620 665
13% Chromium Stainless
80 L80-13Cr 0.22 16 0.5 13 0.25 552~655 655
95/110 0.04 max 0.6 4 13 1.5
95/111 0.04 max 0.6 5 13 2.5


Mo Steels – High Strength Low Alloy
Steel
High strength low alloy (HSLA) steels have been developed since the 1960s originally for large diameter oil- and gas
pipelines. The requirement was high strength as compared to mild carbon steel, combined with improved toughness and
good weldability.
HSLA steel typically contains 0.07 to 0.12% carbon, up to 2% manganese and small additions of niobium, vanadium and
titanium in (usually max. 0.1%). in various combinations. The material is preferrably produced by a thermomechanical
rolling process, which maximizes grain refinement as a basis for improved mechanical properties.
Molybdenum has played an important role in the initial development. The addition of 0.1-0.2% molybdenum produces a
fine grain structure of acicular ferrite and substantially enhances the precipitation hardening effects achieved with the
other alloying elements.
Consequently, an estimated 2 million tons of Mo containing HSLA steels for pipelines have been produced worldwide
during the 1970s. During the following years developments of the rolling and cooling techniques resulted in
improvements of the as rolled microstructure to the extent, that API X70- (70ksi yield strength) requirements can largely
be met without the addition of molybdenum. However, for oil and gas transmission pipelines through regions with
extreme climate conditions substantial quantities of molybdenum continue to be used to meet the low temperature
toughness requirements of the steel. Likewise, for applications where the wall thickness exceeds 20 mm the addition of
molybdenum is common to obtain a uniform structure with the desired combination of strength and toughness and good
weldability properties.
Presently, there is a strong trend towards increasing the operating pressure of the future long distance gas pipelines. This
will take the required steel properties to X80 and higher. Steel producers are making good progress to meet this
challenge, and it is not unlikely, that molybdenum will see a comeback in HSLA steels in that the present base
formula ( e.g. 0.08 C, Nb, Ti) will be upgraded again with 0.1 to 0.2% Mo.


Mo Steels – High Strength Low Alloy
Steel
Composition range of HSLA steels (%)
C Mn Nb V Mo
0.06 - 0.12 1.4 - 1.8 0.02 - 0.05 0 - 0.06 0.2 - 0.35


Mo Steels – Maraging Steels
Maraging steels are carbon free iron-nickel alloys with additions of cobalt, molybdenum, titanium and aluminium. The
term maraging is derived from the strengthening mechanism, which is transforming the alloy to martensite with
subsequent age hardening. Air cooling the alloy to room temperature from 820°C creates a soft iron nickel martensite,
which contains molybdenum and cobalt in supersaturated solid solution. Tempering at 480 to 500°C results in strong
hardening due to the precipitation of a number of intermetallic phases, including, nickel-molybdenum, iron-molybdenum
and iron-nickel varieties.

With yield strength between 1400 and 2400 MPa maraging steels belong to the category of ultra-high-strength materials.
The high strength is combined with excellent toughness properties and weldability.
Typical applications areas include:
•aerospace, e.g. undercarriage parts and wing fittings,
•tooling & machinery , e.g. extrusion press rams and mandrels in tube production, gears
•Ordnance components and fasteners.
Maraging Steels
Yield Strength
% Alloy content
Type (0,2% proof stress)
(MPa) Ni Co Mo Ti Al
18Ni1400 1400 18 8.5 3 0.2 0.1
18Ni1700 1700 18 8 5 0.4 0.1
18Ni1900 1900 18 9 5 0.6 0.1
18Ni2400 2400 17.5 12.5 3.75 1.8 0.15
17Ni1600 (cast) 1600 17 10 4.6 0.3 0.05


Mo Steels – Tool & High Speed Steel
One of the earliest applications of molybdenum was as an efficient and cost effective replacement for tungsten in tool steels and high-
speed steels. The atomic weight of molybdenum is roughly half that of tungsten and therefore 1% Mo is roughly equivalent to 2% tungsten.
Because these highly alloyed steels are used in the working, cutting and forming of metal components, they must possess high hardness
and strength, combined with good toughness, over a broad temperature range.
Tool Steels
Molybdenum in tool steels increases their hardness and wear resistance. By reducing the 'critical cooling rate' molybdenum promotes the
formation of an optimal martensitic matrix, even in massive and intricate moulds which cannot be cooled rapidly without distortion or
cracking. Molybdenum also acts in conjunction with elements like chromium to produce substantial volumes of extremely hard and abrasion
resistant carbides. As the physical demands placed on tool steels increase, so too does the molybdenum content.
High speed steels
When tool steels contain a combination of more than 7% molybdenum, tungsten and vanadium, and more than 0.60% carbon, they are
referred to as high speed steels. This term is descriptive of their ability to cut metals at 'high speeds'. Until the 1950's, T-1 with 18%
tungsten, was the preferred machining steel but the development of controlled atmosphere heat treating furnaces made it practical and cost
effective to substitute part or all of the tungsten with molybdenum. Additions of 5-10% Mo effectively maximize the hardness and toughness
of high-speed steels and maintain these properties at the high temperatures generated when cutting metals. Molybdenum provides another
advantage: at high temperature, steels soften and become embrittled if the primary carbides of iron and chromium grow rapidly in size.
Molybdenum, especially in combination with vanadium, minimizes this by causing the carbides to reform as tiny secondary carbides which
are more stable at high temperatures. The largest use of high-speed steels is in the manufacture of various cutting tools: drills, milling
cutters, gear cutters, saw blades, etc.
Typical Compositions of
Selected High-Speed Steels (%) % Molybdenum content in tool steels
Grade C Cr Mo W V Steel type Mo
T-1 0.75 - - 18 1.1 Plastic Moulding steels up to 0.5
M-2 0.95 4.2 5 6 2 Cold work steels 0.5 - 1.0
M-7 1 3.8 8.7 1.6 2 Hot work steels up to 3.0
M-42 1.1 3.8 9.5 1.5 1.2


Molybdenum Grade Cast Irons
Molybdenum increases the strength and hardness of cast irons by depressing the pearlite transformation
temperature. It also increases elevated temperature strength and creep resistance. High chromium irons,
containing 2-3% molybdenum exhibit significantly greater impact toughness than Mo-free grades and are
ideal for severe abrasive conditions like those encountered in mining, milling, crushing etc. These cast irons
have acceptable properties as cast. This eliminates the need for a costly heat treatment and makes them a
cost effective alternative to other grinding materials. Reduced levels of austenite formers, such as nickel and
manganese, also minimize the retention of low temperature austenite - a potential cause of premature
failures.

There has been growing interest in the use of high silicon-molybdenum ductile irons with up to 4% Si and 1%
Mo. Their good strength up to 600°C makes them a viable and cost effective replacement for more highly
alloyed irons and steels in elevated temperature applications such as turbocharger housings, engine exhaust
manifolds and furnace components. The austempered nodular irons develop a unique microstructure
capable of strengths in excess of 1000 MPa (145 ksi) with good impact toughness. Their exceptional
properties are ideal for critical applications such as the large gears and crankshafts required for power
generation, ship propulsion and large mining equipment.


Other Molybdenum Alloys
1. Super Alloys
2. Molybdenum Metal & Alloys made by Power Metallurgy Techniques

Other Applications Of mo Compounds

1. Catalysts - MoS2 in crude refining, Mo-based catalysts in coal liquification
2. Pigments - Molybdenum oranges, Zn-Mo White, Molybdophosphoric acid dyes
3. Corrosion inhibitors - Sodium molybdate as a substitute for chromates
4. Smoke suppressants - Ammonium octamolybdate is used with PVC
5. Lubricants - Molybdenum disulfide
6. Molybdenum chemicals in agriculture, pharmaceuticals


Other Molybdenum Alloys & Chemicals
1. Super Alloys
2. Molybdenum Metal & Alloys made by Power Metallurgy Techniques

Other Applications Of Mo Compounds

1. Catalysts - MoS2 in crude refining, Mo-based catalysts in coal liquification
2. Pigments - Molybdenum oranges, Zn-Mo White, Molybdophosphoric acid dyes
3. Corrosion inhibitors - Sodium molybdate as a substitute for chromates
4. Smoke suppressants - Ammonium octamolybdate is used with PVC
5. Lubricants - Molybdenum disulfide
6. Molybdenum chemicals in agriculture, pharmaceuticals

Molybdenum-99 is a parent radioisotope to the daughter radioisotope technetium-99m, which is used in
many medical procedures. Molybdenum disulfide (MoS2) is used as a solid lubricant and a high-pressure
high-temperature (HPHT) antiwear agent. It forms strong films on metallic surfaces and is a common
additive to HPHT greases—in case of a catastrophic grease failure, thin layer of molybdenum prevents
contact of the lubricated parts. Molybdenum disilicide (MoSi2) is an electrically conducting ceramic with
primary use in heating elements operating at temperatures above 1500 °C in air. Molybdenum
trioxide (MoO3) is used as an adhesive between enamels and metals.] Lead molybdate (wulfenite) co-
precipitated with lead chromate and lead sulfate is a bright-orange pigment used with ceramics and
plastics. Molybdenum powder is used as a fertilizer for some plants, such as cauliflower.


Molybdenum Chemicals
Aq NaOH, aq Na2MoO4 H2
NH3 (NH4)2Mo2O7 S (NH4)2MoS4
MoO3 Calcine/subli (NH4)6Mo7O24
me
roast RS2
air MoCl5
H2 H2/CO NH3 [(RS2)2Mo2OxSy]
1000 1000 1000
C C C
MoS2 CO 70
Cl
bar
2 EtMgBr
Mo2C Mo2N
ice
NH3
C+H2 1100
Mo 1500 C Mo(CO)6
C


Molybdenum Compounds Applications
Application Partner

C N O Si P S

Mo2C Mo2N MoO3 MoSi2 MoP MoS2
molybdate

Catalysis

Lubrication

Corrosion
inhibition
Pigments
Smoke
suppression
Ceramics

Nanomaterials

Molybdenum Catalysts
Hydrotreatment of petroleum
Remove S = hydrodesulfurisation = HDS
Remove N, O compounds

Selective oxidation
Methanol to formaldehyde

Propene to acrolein and acrylontrile

For polymers and plastics


Molybdenum Lubricants
Molybdenum―sulfur Compounds in Lubrication
61
Molybdenum disulfide
Dry lubricant Used in e.g.
greases,
dispersions,
friction materials and
bonded coatings.

Molybdenum complexes
soluble in petroleum oils Anti-wear and
and other organic solvents extreme pressure additives

Decompose at friction modifiers
hot metal surface in lubricating oils and greases.
Protective film
MoS2 layer


Molybdenum Corrosion Inhibitors and
Pigments
Application
Steel, Al, Cu
Central heating Sodium molybdate
systems
Automobile engine
coolant
Paints Zinc, calcium, strontium molybdate
plastics Molybdenum orange: lead molybdate
+ lead chromate
rubber
Phosphomolybdates
ceramics

Molybdenum Calcium Zinc Phosphomolybdate Corrosion


Molybdenum Calcium Zinc Phosphomolybdate Corrosion

Mechanism of
Protective Action of Molybdate
Interacts with the metallic substrate ― adsorption.
Fills gaps and promotes the formation of an adherent
oxide layer.
Prevents corrosion of the underlying substrate ―
passivation.


Mechanism of Smoke Suppression by Molybdate

Plasticizers ― greatly enhance the polymer combustibility.
Molybdate reduces smoke from burning PVC.
The char produced from the AOM containing compound was MoO2.
Cross-links the plastic to form a surface char..


Molybdenum Carbide Catalyst Nanotubes


Molybdenum Carbide Catalyst Nanotubes

Series on Neutron Techniques and Applications –
Vol. 3

Vibrational Spectroscopy with Neutrons With Applications in Chemistry,
Biology, Materials Science and Catalysis


Why Molybdenum ?

WHY USE MOLYBDENUM?
Chemical versatility
Low toxicity
ALWAYS WORTH THINKING
MOLYBDENUM

Cr Can FAMD Get Into
Mn Molybdenum ?
next ?


Molybdenum Market Overview of Current & Future Supply

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