Talk:Molybdenum

220.237.184.180 (talk) 08:02, 19 November 2007 (UTC)Template:Oldscipeerreview Template:Chemical Element Elementbox converted 11:40, 6 July 2005 by Femto (previous revision was that of 17:53, 5 July 2005).

Nuclear Isotopic Stability

Why is Mo100 considered to be one of the "unstable" isotopes if it has a half life of 10,000,000,000,000,000,000 years? That's almost 100 million times longer than the current Universe's elapsed existence (est. 18 billion years)... I quote: "Molybdenum-92 and molybdenum-100 are the only naturally occurring isotopes which are not stable. Molybdenum-100 has a half-life of approximately 1×10^19 y and undergoes double beta decay into ruthenium-100." 137.53.85.122 (talk) 22:24, 17 December 2007 (UTC) Alex Cranson

Quick heads up

You may observe some sections of the article getting significantly smaller. I'm currently working on getting accurate sourced info for molybdenum, and I've found it's much easier to just rewrite it than try to find sources for each fact. Worry not, any gaps I create will be filled. --Cryptic C62 · Talk 00:26, 6 May 2007 (UTC)

Moses

Does anybody know if Molybdenium Selenium Sulfide exists? If it did it would have the distinction of spelling out "MoSeS". Because MoS2 and MoSe2 both exist, and because Selenium and Sulfur have similar chemical properties, I'm thinking that there's a possibility of it actually being real. Anyone care to enlighten me?

Nah, man. Selenium and molybdenum don't hang out with sulphur when they're together. They're all like "we need alone time, and your valence charge would be totally weird for us right now." --justing magpie 20:20, 18 July 2006 (UTC)

Sorry to disappoint you, but such a compound would be MoSSe (if it would exist ..) .. --Dirk Beetstra ^{T C} 20:33, 18 July 2006 (UTC)

Price Hike

Would anyone care to enlighten the rest of us as to the reasons behind the over 1000% rise in price over the past few years of this element? What other uses does it have? I suspect that the price rise is due to military reasons, but this is speculation.

I can only give you speculation. I grew up in the shadow of the Climax Molybdenum mine in Leadville, Colorado. It was once the largest producer of moly. It has been shut down since the 1980s, primarily because the moly market follows the steel market. When the steel markets collapsed, so did the market for moly. Unfortunatly for Climax, every time the price of moly rises enough to consider reopening the mine, the byproduct mills attached to other mines start selling their leftover moly and the market gets swamped again.

Military uses are certainly a possibility, but I suspect civil expansion in Asia are a bigger factor. The steel market is currently returning in Asia, and that is what is probably driving up moly prices again. --Mdwyer 20:45, 3 February 2006 (UTC)

I also don't know exactly why moly is up so much. And I've done a lot of research on the subject. M guess is that this is evidence of inflation. Jason Hommel 08:30, 16 August 2006 (UTC) Here's a link for further research about investing in molybdenum: http://www.silverstockreport.com/email/IGMI_Today.html

The price hike is related to supply-demand. Demand is up for two reasons. 70-plus percent of Moly is used to make various steels, and steel demand is up (like that of all base metals) mainly because of economic expansion in China and other developing economies. A lot of the remaining molybdenum is used to make catalyst for hydrodesulfurization of petroleum. Recent petroluem supply disruptions (Katrina, Iraq, etc) have driven the price of oil higher, thereby making it more economical to mine the "dirtier" oil deposits such as the Canadian tar sands. The higher sulfur levels of this crude oil, combined with continuing regulations aimed at reducing the permissible sulfur content of automobile fuels has led to increased demand from the catalyst side. While catalysts only support around 15 to 25 percent of molybdenum use, the CAGR of molybdenum usage in catalysts is more or less double that of steel, so catalysts are a less important but still significant source of the higher damand.

On the supply side, there are three main reasons for the shortage. The first is that because it was so cheap only a few years ago, few primary molybdenum mines have been developed in recent years. The high capital and time requirements for new mine development have allowed demand to outpace supply. However, in recent years byproduct moly producers have increased production to take advantage of the high price (sometimes at the expense of copper production), so while this factor was important a few years ago, it is not really an issue now. The second problem is that roasters have also been a bottleneck. The extra moly that was coming from the mines have just been piling up in the parking lots of the roasters. This should be less of an issue in the coming years as well, as some roaster capacity is expected to come online in 2007. The third factor is China, which produces about 25% of the world's molybdenum, much of which is roasted in uncrontrolled "mom and pop" style hearths that emit a lot of SO2. Under international pressure from recent environmental accidents, they have clamped down on molybdenum production domestically, thereby taking quite a bit of moly off the market. I have no idea when and if this aspect will be alieved. —The preceding unsigned comment was added by 198.176.208.75 (talk) 21:24, 12 December 2006 (UTC).

Safety

I don't know much about the mining process but is open pit mining safer then it was in the past?

I'm afraid I'm probably going to spout the company line, here, so take this with a huge grain of salt... I was under the impression that Moly mining was relatively safe, especially as compared to coal mining. Tunnel collapse and equipment accidents abound, but explosions and bad air seem to be less of a problem. The milling, as well, seems to be mostly a mechnical process, and doesn't seem to require the same dangerous chemicals as does, say, gold extraction. Open pit, I should think, is even less dangerous. I have heard tales of people cartwheeling giant DC8 dozers down cliffsides, but otherwise, I didn't hear about too many accidents around the Climax mine. Are these specific hazards you're thinking about? --Mdwyer 00:13, 24 March 2006 (UTC)

Molybdenum Oxide (MoO3)seems to be obtained by roasting Moly Sulphide (MoS2). It is also mentioned that it is obtained from Wulfenite (PbMoO4) and Powellite (CaMoO4). Moly Oxide does not seemed to be mined. Does anyone know why not? Does anyone know the process for converting Wulfenite or Powellite to Moly oxide? Martin Essenberg 02:06, 2 June 2006 (UTC)Martin

Pronunciation

Should we put something on the article about the pronunciation of 'Molybdenum', since it is a quite strange element name. --Redtitan 23:13, 17 July 2006 (UTC)

I took care of it. That's a good idea. I think when I was little I called it "molly-bed-i-um"... --justing magpie 20:16, 20 July 2006 (UTC)

I often wonder if this was what Robin was talking about when he used to say "holy moly, Batman". 62.30.197.24 05:39, 10 December 2006 (UTC)

Wow. Sorry, ^that was just awful. --Cryptic C62 · Talk 17:51, 2 April 2007 (UTC)

soft or hard??

um the world book encyclopedia describes molybdenum as being "hard" rather than "soft". I have found some contradiction of whether it is soft or hard in numerous websites. could someone please confirm? —The preceding unsigned comment was added by 203.191.186.7 (talk) 06:27, 13 March 2007 (UTC).

Report on Moly

I was reading this report today, and don't know if it will be of help to this article. It goes into more detail about the applications of moly [1] This report is from Blue Pearl, a moly mining company. —The preceding unsigned comment was added by 64.5.88.115 (talk) 00:43, 4 April 2007 (UTC).

References

• M. P. Coughlan (1983). "The role of molybdenum in human biology". Journal of Inherited Metabolic Disease. 6 (1): 70–77. doi:10.1007/BF01811327.
• Paul B. Coffman (1937). "The Rise of a New Metal: The Growth and Success of the Climax Molybdenum Company". The Journal of Business of the University of Chicago. 10 (1): 30–45.
• M. E. Wieser, J. R. De Laeter (2007). "Absolute isotopic composition of molybdenum and the solar abundances of the p-process nuclides ^92,94Mo". Phys. Rev. C. 75: 055802. doi:10.1103/PhysRevC.75.055802.
• Bob King (2004). "Minerals explained 39: Molybdenite". Geology Today. 20 (1): 34–37. doi:10.1111/j.1365-2451.2004.00444.x.
• Barceloux, Donald G. and Barceloux, Donald (1999). "Molybdenum". Clinical Toxicology. 37 (2): 231–237. doi:10.1081/CLT-100102422.{{cite journal}}: CS1 maint: multiple names: authors list (link)
• The history of development of molybdenum alloys for structural applications
• [2]
• [3]
• C. W. K. Scheele (1779). "Versuche mit Wasserbley;Molybdaena". svenska vetensk. Academ. Handlingar. 40: 238.
• P. J. Hjelm (1788). "Versuche mit Molybdäna, und Reduction der selben Erde". svenska vetensk. Academ. Handlingar. 49: 268.
• Arthur Linz (1955). "Industrial Applications of Molybdenum Chemistry - Introduction". Industrial & Engineering Chemistry. 47 (8): 1492–1493. doi:10.1021/ie50548a017.
• D. H. Killeffer (1955). "Complexities of Molybdenum Chemistry". Industrial & Engineering Chemistry. 47 (8): 1493–1494. doi:10.1021/ie50548a018.
• [4]--Stone 17:25, 18 June 2007 (UTC)

Production

Molybdenite is heated with air to temperatures of 700°C during this roasting process the sulfide is turned into the molybdenum(VI) oxide.

2MoS₂ + 7O₂ → 2MoO₃ + 4SO₂

For purification the molybdenum oxide is disolved in ammonia forming a ammonium molybdate (NH₄MoO₄) or the oxide is sublimed.

Most of the produced molybdenum oxide is mixed with iron oxide and melted in an electric discarge oven to get ferromolybdenum which is used for the steel production.

The pure metal is produced by reduction of molybdenum(VI) oxide with hydrogen.

MoO₃ + 6H₂ → Mo + 6H₂O --Stone 14:32, 20 June 2007 (UTC)

Sixth or Fourth?

In the introduction it says "It has the sixth highest melting point of any element", but under Characteristics it says "only tantalum, rhenium and tungsten have higher melting points" - but that's only three things...

82.41.211.70 12:48, 4 August 2007 (UTC)

That's because they neglected to mention that the other positions belong to osmium, laurencium and carbon. 220.237.184.180 (talk) 08:02, 19 November 2007 (UTC)