Talk:Molybdenum

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Good article Molybdenum has been listed as one of the Natural sciences good articles under the good article criteria. If you can improve it further, please do so. If it no longer meets these criteria, you can reassess it.
October 7, 2009 Good article nominee Listed
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Elementbox converted[edit]

Elementbox converted 11:40, 6 July 2005 by Femto (previous revision was that of 17:53, 5 July 2005).

Thiolates[edit]

Apparently molybdenum thiolates are really common. We should have a section in this article on them.

Quodfui (talk) 19:21, 18 June 2008 (UTC)

Toxicity[edit]

Opening paragraph: "although excess molybdenum can be toxic in some animals". This phrase seems a bit redundant (although appearing in many other articles also) given that too much of any substance is toxic. Maybe a bit pedantic to make the point but if this is a Scientific based article then i'm sure accuracy should be aspired too. N.B The last sentence is not a call for any grammatical errors on my part to be brought to attention. —Preceding unsigned comment added by 213.161.91.194 (talk) 16:08, 11 January 2008 (UTC)

The MSDS cited by the article (rembar.com) claims Mo is nontoxic, but the ORNL reference and an MSDS from CERAC (another Mo supplier) both show it's toxic, especially in powdered form. If someone has data to refute these, please Be Bold :-), and also please add an explanation here for the rest of us. The ORNL page can be misleading if you only pick out occasional sentences. Mwistey (talk) 07:35, 20 October 2008 (UTC)

Nuclear Isotopic Stability[edit]

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

I think that unstable means that it is radioactive and does decay, it doesn't matter how long the half-life is. 04cah (talk) 03:45, 26 October 2008 (UTC)

Quick heads up[edit]

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[edit]

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)
I'll give the man a serious answer. Since selenium is one level below sulfur in the Periodic Table, those two elememts have similar chemical properties. Molybdenum will combines with sulfur and it will combine with selenium, too. If you mixed up molybdenium powder with powedered sulfur and powdered selenium, and heated that in an inert atmosphere in a non-reactive container (I'll leave that you for you to pick out the metals for, but a platinum-iridium alloy might be a good one.) you will get a molybdenium compound with selenium and sulfur. It will be in the form of a crystal or an amorphous mass, and within that, the ratio between selenium and sulfur might not necessarily be 1:1. Anyway, even if it was, the MoSeS would be an empirical formula, and not necessarily a molecular formula. But something close to it as an empirical formula would exist.
Let the numbers in parenthesis in the following be read as subscripts. Then, what you would get would be MoSe(2-x)S(x), where 0 < x < 2. If you carefully chose the ratios of molybdenum, selenium, and sulfur in your container, you might be able to control the value of x. I've hit the limit on my knowledge of this kind of chemistry. 72.146.43.188 (talk) 07:21, 14 September 2008 (UTC)

See the mineral Drysdallite Mo(S,Se)2 on Mindat. Vsmith (talk) 14:32, 14 September 2008 (UTC)


Safety[edit]

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[edit]

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??[edit]

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[edit]

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[edit]

Production[edit]

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?[edit]

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)

42[edit]

Deleting vandalism by User talk:194.114.147.78. I'm researching Moly, and noticed this entry in the talk page. Apologies if I'm not doing this correctly (I tried to just "Undo" the entry, but it didn't work). --Joe Sperrazza (talk) 16:07, 25 April 2008 (UTC)

Supply and Demand[edit]

In this section there are two references in the vein of "an average reactor contains about 520,000 feet of stainless steel alloy", Wouldn't that be 520,000 cubic feet? And, as this is a scientific article, Wouldn't that better be expressed in cubic meters? —Preceding unsigned comment added by 192.193.207.151 (talk) 17:51, 28 March 2008 (UTC)

May refer to stainless steel alloy tubing, which to my understanding is typically quantified by a linear measure. May alternatively refer to stainless steel alloy sheet, typically quantified by square feet or square metres. Should be verified, and clarified in the text. RCopple (talk) 16:20, 26 February 2009 (UTC)

C Class[edit]

How can this article be rated C-class when there is no such thing? See Quality Scale. I won't revert this since I have already reverted a number of identical edits from this user across wikipedia and so would like input from others. Polyamorph (talk) 15:20, 30 June 2008 (UTC)

Ok, discussion started at Wikipedia_talk:WikiProject_Chemicals#C Class. Polyamorph (talk) 16:07, 30 June 2008 (UTC)

dead links[edit]

The links to the original papers of Scheele and Hjelm work from my computer is it due to the fact of some geographical block to that library or doe they work for all? --Stone (talk) 21:55, 28 August 2008 (UTC)

Molybdenum deprivation[edit]

Molybdenum deprivation stalled the development of life for about 2 billion years: http://www.dailygalaxy.com/my_weblog/2008/03/evolution-of-li.html http://www.sciencedaily.com/releases/2008/03/080326142229.htm -- 93.106.123.241 (talk) 11:36, 5 September 2008 (UTC)

Thanks for the contribution, but I believe the article already mentions this: "In March 2008, researchers reported that they had found strong evidence for the hypothesis that a scarcity of molybdenum in the earth's early oceans was a limiting factor in the further evolution of eukaryotic life". -- —Preceding unsigned comment added by Rmrfstar (talkcontribs)

Shouldn't Molybdenum be in Category:Biology and pharmacology of chemical elements ? Eldin raigmore (talk) 20:45, 16 May 2009 (UTC)

Question[edit]

Question from a reader...how does a metal burn at 600°C before it melts at 2623°C? would it not melt first then burn? Is this data verified?? (I can't read the cited source on the internet and have long since graduated college and don't have time to look in a library.)

copied from the article to the talk page --Stone (talk) 17:31, 13 January 2009 (UTC)
Simple answer: coal does not melt before it burns. The metal will reach the melting temperature with all the energy gained by the oxidation so it will melt. --Stone (talk) 22:17, 13 January 2009 (UTC)

A more detailed answer is: The metal itself does not melt, it burns in the solid state. The heat of combustion vaporizes the oxide. Because of the lower MP (795 °C) and BP (1155 °C) of Molybdenum(VI) oxide (q.v.), the oxide can escape from the combustion region as a vapor (recondensing as a fume) providing an unobstructed surface for the reaction with oxygen to continue. This is similar to the much more extreme example of coal (carbon) which burns in the solid state with the combustion product (CO2) escaping as a vapor (gas). Dpasek (talk) 05:04, 29 January 2009 (UTC)

Moved from the main article (commented text, might be unsuitable)[edit]

Supply and demand[edit]

Although current molybdenum production meets demand, refiners, or roasters, are expected to run into a shortfall between 2009 and 2015, depending on demand.[citation needed]

A roaster processes the molybdenum into a fine powder, pellets, or other forms. Total world molybdenum roaster capacity is currently 320 million pounds per year, barely enough to meet demand. There is not much excess roasting capacity, and no one is actively permitting for the production of any new roasters in the United States. Global roaster capacity also looks limited, and a future roaster shortage is predicted. The data above are based on the assumption that mines will be able to increase output.[citation needed]

Western demand is projected to increase by around 3 percent annually, while China and the CIS demand is projected to increase by around 10 percent annually, increasing overall global demand by around 4.5 percent annually. Increasing demand can be attributed to two main factors. Hydroprocessing catalysts are becoming essential for crude oil. The other contributing factor is the increase in nuclear reactor construction. There are 48 nuclear reactors to be built by 2013, and approximately 100 are to be built by 2020. The International Molybdenum Association (IMOA) says that an average reactor contains about 520,000 feet (160,000 m) of stainless steel alloy. Some larger reactors contain over 1 million feet of stainless steel alloy.[citation needed]

expected production of a mine is for me a violation of Wikipedia:What Wikipedia is not#Wikipedia is not a crystal ball 254,000 tons of molybdenum were discovered on Hainan, off the southern coast of China, on 6 October 2008. The mine is expected to produce 7,000 tons of molybdenum annually.[1]

There had been a major discovery announced 6 October 2009, underneath of the Kennecott Copper Open Pit in Salt Lake County, Utah. [5] Samuelsenwd (talk) 02:25, 7 October 2009 (UTC)
Thanks! Though we'll have to wait for more detailed and substantiated reports to include this into the article. Materialscientist (talk) 02:38, 7 October 2009 (UTC)

Are you sure that {{chem}} page is right?[edit]

{{chem|MoO|4|2-}} = MoO2−
4
does NOT show up as MoO42- for me. All I see is the letters and a 4 with no -2. Look at the LEAD. Anybody else have this problem? SBHarris 03:38, 24 July 2009 (UTC)


This article deserves GA status. It is well written, neutral, stable and well referenced with in-line citations. A few minor problems had been fixed during the review, as documented below. Materialscientist (talk) 05:41, 7 October 2009 (UTC)

GA Review[edit]

This review is transcluded from Talk:Molybdenum/GA1. The edit link for this section can be used to add comments to the review.
  • Please check the dead links here and "citation needed" tags.
  • Tried to get rid of all but one of them. The australian one needs more time.--Stone (talk) 12:43, 27 September 2009 (UTC)
  • Removed the australian reference and added two others.--Stone (talk) 21:09, 29 September 2009 (UTC)
  • Clarify "free oxygen" (gas, atoms, else ?)
  • This is diatomic oxygen gas. --Stone (talk) 20:31, 27 September 2009 (UTC)
  • Changed to oxygen. free is missleading.--Stone (talk) 21:09, 29 September 2009 (UTC)
  • Clarify "alkaline water"
  • strong base like potassium hydroxide in water--Stone (talk) 20:31, 27 September 2009 (UTC)
  • Changed.--Stone (talk) 21:09, 29 September 2009 (UTC)
  • "reached a peak of $103,000 per tonne in June 2005" - why?
  • The resposible person is not named! I think it is like always, high demand and a lot of gamblers on the stock market.--Stone (talk) 20:31, 27 September 2009 (UTC)
  • added the phrase: due to increased demand.--Stone (talk) 21:09, 29 September 2009 (UTC)
  • Is it true that oxidation state zero is among the most stable ones ? How about 2+ (sulfides) ? This refers to bolding some values in the oxidation state table.
  • Zero is stable enough if it is bulk material, but you are right it is not among the most stable ones in the lab.--Stone (talk) 12:43, 27 September 2009 (UTC)
  • Changed.--Stone (talk) 21:09, 29 September 2009 (UTC)
  • I changed some {{chem templates into usual <sub, <sup because the formulas get split up at line break. Materialscientist (talk) 10:02, 27 September 2009 (UTC)
  • This is just a hint that the info on number of Mo enzymes is obsolete in the article. Could you update that? Materialscientist (talk) 11:15, 30 September 2009 (UTC)
  • Sorry I found no newer numbers. I put the numbers in from the journal mentioned above--Stone (talk) 03:57, 7 October 2009 (UTC)
    I failed too - new articles simply re-cite old reviews. A specialist is needed here. Materialscientist (talk) 05:41, 7 October 2009 (UTC)

"Molybdanium"[edit]

UNC department of chemistry website (http://www.chem.unc.edu/) is decorated with a periodic table image. From "iodum" I can guess that it was supposed to show Latin names of the elements, but what is "molybdanium" then? This article gives "Molybdaenum" as the Latin name, other sources give also "molybdenum" or "molybdenium". Which one is correct? — Mikhail Ryazanov (talk) 23:20, 26 August 2011 (UTC)

File:Molybdenum crystaline fragment and 1cm3 cube.jpg to appear as POTD soon[edit]

Hello! This is a note to let the editors of this article know that File:Molybdenum crystaline fragment and 1cm3 cube.jpg will be appearing as picture of the day on January 16, 2012. You can view and edit the POTD blurb at Template:POTD/2012-01-16. If this article needs any attention or maintenance, it would be preferable if that could be done before its appearance on the Main Page so Wikipedia doesn't look bad. :) Thanks! howcheng {chat} 22:09, 14 January 2012 (UTC)

Picture of the day
Molybdenum crystal and cube

A single crystalline 1 cm3 cube and a crystalline fragment of molybdenum, the latter created by electron beam melting. Molybdenum is a silvery metal that has the sixth-highest melting point of any element. It readily forms hard, stable carbides, and for this reason it is often used in high-strength steel alloys.

Photo: Alchemist-hp
ArchiveMore featured pictures...


Applications: x-ray source[edit]

Moly is often used as an x-ray source for crystallography, but I'm not sure this really merits an addition to the applications section. — Preceding unsigned comment added by 98.223.234.93 (talk) 05:09, 21 February 2012 (UTC)

Deficiency in TPN citation - G-tube feeding?[edit]

Can someone find a citation for deficiency seen in TPN patients? Would this occur as well in G-tube feeding (enteral nutrition), or are the formulas used for G-tube feeding better made (for want of a better term).. Given the role of Mo-enzymes in brain development, one wonders whether any research has looked at TPN/G-tube caused Mo-deficiency (or other trace elements) in recovery from severe brain injury. — Preceding unsigned comment added by Jimw338 (talkcontribs) 17:27, 26 February 2012 (UTC)

What I read in the two reports I post here the molybdenum deficiency is not wide spread, but was first discovered in TPN patients.--Stone (talk) 20:13, 26 February 2012 (UTC)

Nanoelectronic applications[edit]

Some interesting new work using MoO3 inter-layered in graphene is at doi:10.1002/adma.201370007/abstract. According to this lay summary, it shows an electron mobility of 1,100 cm2/Vs which implies very fast devices are possible in comparison to planar silicon. LeadSongDog come howl! 16:43, 4 January 2013 (UTC)

Oxidation states[edit]

In the infobox the oxidation states are listed to be all from -6 to 2 except 0, while in the table in the Compounds and chemistry section 0 is present and 1 is not. Which is correct? Ulflund (talk) 21:36, 28 August 2013 (UTC)

Physics.org article about molybdenum and Mars[edit]

Came across this article about molybdenum and Mars. Thought it might be a relevant topic for this article. Thoughts? — Preceding signed comment added by Cymru.lass (talkcontribs) 00:13, 29 August 2013 (UTC) Hi CL. FWIW this is the first time I've ever seen a mechanism suggested for the production of RNA and it seems very exciting though the theory has a long way to go. Materialscientist reverted my orginal edit on the not unreasonable grounds that the source (BBC) wasn't suitable for a good article but I replaced it at 18:59 with a snippet from New Scientist -which I hope satisfies everybody. Regards JRPG (talk) 19:16, 30 August 2013 (UTC)

I should have apologised. I hadn't seen your edit before updating the article JRPG (talk) 20:15, 30 August 2013 (UTC)

Abundance in oceans[edit]

I linked the statement about abundance in the Earth's crust to the corresponding article and went to do the same for the oceanic abundance, but there appears to be a discrepancy. In this article we have it as the 25th most abundant in the oceans, whilst Abundances of the elements (data page)#Sea water (I presume "sea water" and "oceans" are synonymous?) has it as 42nd most abundant. Am I wrong in my assumption that these are measuring the same thing or is one of the articles in error? danno_uk 17:44, 18 March 2014 (UTC)

Production map[edit]

I've removed the map File:2005molybdenum (mined).PNG as the data is rather outdated and the distribution/location of the dots was confusing. Vsmith (talk) 14:12, 13 April 2014 (UTC)

  1. ^ Jones, Nick (2008-10-06). "Large molybdenum mine found in south China". Business. Retrieved 2008-10-06.