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Stanley Meyers HHO WFC facts about Molybdenum Properties (also referred to as ‘Moly’) is a transition metal. The pure metal is silvery white in color, is very hard, and has one of the highest melting points of all pure elements.
In nature, molybdenum occurs in the form of molybdenite and wulfenite and is most commonly used as alloy in stainless steels and in alloy steels. Stainless steels include the strength and corrosion-resistant requirements for water distribution systems, food handling equipment, chemical processing equipment, home, hospital, and laboratory equipment. Alloy steels include the stronger and tougher steels needed to make automotive parts, construction equipment, and gas transmission pipes. A rough breakdown of its use is in machinery (35%), electrical applications (15%), in transportation (15%), in chemicals (10%), in the oil and gas industry (10%), and assorted others applications (15%).
Molybdenum’s unique appeal is drawn from its high melting temperature, fifth highest of all the elements (4,730 degrees Fahrenheit); 2000 degrees higher than the melting point of steel and 1,000 degrees higher than the melting point of most rocks.
Due in large part to the exponential growth in China, the demand for molybdenum has skyrocketed in the past 5 years with the price of molybdenum per pound increasing from around $2 per pound in 2000 to highs in the mid 30’s to settling most recently in the mid 20’s.
The result is a tremendous opportunity to capitalize on worldwide molybdenum demand. Considering Molybdenum is incredibly dense, it’s not necessary to define a large area to achieve significant tonnage. For demonstrative purposes only, a grade of 1% Mo per tonne (2205 lbs) could yield approximately twenty-two (22) pounds of molybdenum. This equates to a gross value of approximately $550 per tonne of rock removed at current prices. A discovery of significant size and grade, coupled with a reasonable cost to mine could potentially be highly profitable.
Characteristics
Molybdenum is a transition metal with an electronegativity of 1.8 on the Pauling scale and an atomic mass of 95.9 g/mole.[2] It does not react with oxygen or water at room temperature. At elevated temperatures, molybdenum trioxide is formed in the reaction 2Mo + 3O2 → 2MoO3.[3]
In its pure metal form, molybdenum is silvery white with a Mohs hardness of 5.5, though it is somewhat more ductile than tungsten. It has a melting point of 2623°C, and, of the naturally-occurring metals, only tantalum, osmium, rhenium, and tungsten have higher melting points.[4] Molybdenum burns only at temperatures above 600°C.[5] It also has the lowest heating expansion of any commercially used metal.[6]
Molybdenum has a value of approximately $65,000 per tonne as of 4 May 2007. It maintained a price at or near $10,000 per tonne from 1997 through 2002, and reached a high of $103,000 per tonne in June 2005.[7]
[edit] Isotopes
Main article: Isotopes of molybdenum
There are 35 known isotopes of molybdenum ranging in atomic mass from 83 to 117, as well as four metastable nuclear isomers. Seven isotopes occur naturally, with atomic masses of 92, 94, 95, 96, 97, 98, and 100. Of these naturally occurring isotopes, five are stable, with atomic masses from 94 to 98. All unstable isotopes of molybdenum decay into isotopes of niobium, technetium, and ruthenium.[8]
Molybdenum-92 and molybdenum-100 are the only naturally occurring isotopes that are not stable. Molybdenum-100 has a half-life of approximately 1×1019 y and undergoes double beta decay into ruthenium-100. Molybdenum-98 is the most common isotope, comprising 24.14% of all molybdenum. Molybdenum isotopes with mass numbers from 111 to 117 all have half-lives of approximately .15 μs.[8]
[edit] Occurrence
Molybdenum output in 2005
The world's largest producers of molybdenum materials are the United States, Canada, Chile, Russia, and China.[9][6]
Though molybdenum is found in such minerals as wulfenite (PbMoO4) and powellite (CaMoO4), the main commercial source of molybdenum is molybdenite (MoS2). Molybdenum is mined as a principal ore, and is also recovered as a byproduct of copper and tungsten mining.[4] Large mines in Colorado (such as the now inactive Climax mine)[10] and in British Columbia yield molybdenite, while many porphyry copper deposits such as the Chuquicamata mine in northern Chile produce molybdenum as a byproduct of copper mining. The Knaben mine in southern Norway was opened in 1885, making it the first molybdenum mine. It remained open until 1973. In 2007, Knaben Molybden AS reopend the mine and produce 100,000 kg of molybdenum disulfide a year.[citation needed]
Molybdenum is the 42nd-most-abundant element in the universe, and the 25th-most-abundant element in Earth's oceans, with an average of 10.8 mt/km³.[5] The Russian Luna 24 mission discovered a single molybdenum-bearing grain (1 × 0.6 µm) in a pyroxene fragment taken from Mare Crisium on the Moon.[11]
A side product of molybdenum mining is rhenium. As it is always present in small varying quantities in molybdenite, the only commercial source for rhenium is molybdenum mines.
[edit] Production
The molybdenite is roasted at a temperature of 700°C and the sulfide is oxidized into molybdenum(IV) oxide by air.
2MoS2 + 5O2 → 2MoO3 + 2SO2
The roasted ore is either heated to 1100°C to sublime the oxide or leached with ammonia, with which molybdenum(IV) oxide forms water soluble molybdates.
MoO3 + NH4OH → (NH4)2(MoO4) + H2O
Copper is less soluble in ammonia, but to remove it from the solution the copper 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. Ferromolybdenum contains 60% of molybdenum.
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