Talk:Lead

Article changed over to new Wikipedia:WikiProject Elements format by maveric149. Elementbox converted 12:19, 10 July 2005 by Femto (previous revision was that of 14:08, 9 July 2005).

WTF. Will someone please get rid of the image on the page. Vandalism. Goddamn. -DWRZ 02:05, 19 March 2007 (UTC)

Isotopes

This section seems wrong. The radiogenic Pb202 should be counted in the unstable istopes ? It would be nice to say what decay generates Pb202. Why does it claim there are only 3 unstable isotopes ? does it mean naturally occuring, or created artificially by some date long ago ? Rod57 (talk) 01:06, 23 May 2008 (UTC)

How is lead created?

Would someone please add a section showing how lead is actually created? I'm a lay person and all I gathered from this article is that lead "occurs naturally, but is rare." I would like some more information 69.138.74.116 (talk) 04:09, 17 March 2008 (UTC)

Most lead is produced from the mineral galena, lead sulfide. The statement that lead occurs rarely in nature means as pure, native lead. It is quite common in combination. Cheers Geologyguy (talk) 14:14, 17 March 2008 (UTC)

Information Sources

Some of the text in this entry was rewritten from Los Alamos National Laboratory - Lead. Additional text was taken directly from USGS Lead Statistics and Information, USGS Periodic Table - Lead, from the Elements database 20001107 (via dict.org), Webster's Revised Unabridged Dictionary (1913) (via dict.org) and WordNet (r) 1.7 (via dict.org). Data for the table was obtained from the sources listed on the main page and Wikipedia:WikiProject Elements but was reformatted and converted into SI units.

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there are many reason to why metals have changed over the years.what do u think happend to pencil lead and why?

Pencils never used lead. It was actually graphite from the time it was first invented. It was just called "lead" due to its similarity. 68.32.134.183 01:02, 8 Jun 2005 (UTC)

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"This true metal is highly resistant to corrosion" Are you sure that this is true? Lead has a rather negative reduction potential and is easily attacked by Oxygen... Its resistance to Sulfuric Acid is only due to the insolubility of PbSO₄! --malbi

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"Lead is the fourth most widely used metal after aluminium, copper and zinc." Isn't iron more widely used than lead? The article on iron says that it's the most common metal in the universe, and the article on aluminum says "Whether measured in terms of quantity or value, aluminium's use exceeds that of any other metal except iron", which would put iron at the top, then. -- Arteitle 07:42, 2 Aug 2003 (UTC)

That also depends on what you mean with "metal" - if you include salts, Calcium or even Sodium might have good chances as well...

By all means, if you think something is wrong then fix it -- All I know was from the sources I cite above (which may be wrong) and I also incorporated a good deal of text that was here before the conversion. --mav 23:55, 3 Aug 2003 (UTC)

Re isotope 204 stablility -- inconsistent?

The isotope table in the article notes that isotope 204 has a half-life of ">1.4E17 years". This seems to indicate that the isotope is not stable, according to my understanding of the term; yet the textual section on "Isotopes" indicates that lead has 4 stable isotopes, including 204. This seems inconsistent.

For comparison, I note that a determination that bismuth isotope 209 was determined to be "not stable after all" at a half life of 1.9E19 years.

I have also seen differing reports as to the stability of lead-204 against either alpha or beta decay. Some tables report it as a stable isotope while others give a very long half-life of ~10E17 years. This data point could actually be more than of just theoretical interest only, because the ratio of radiogenic lead to nonradiogenic lead (Lead-204 is not produced by any of the decay chains of the heavy long-lived radioactive isotopes) is one way to determine the age of a sample containing uranium, and such methods are often disputed by creationists who claim radioactive dating is wrong. --24.80.110.173 06:47, 7 August 2005 (UTC)

The article doesn't seem to mention the price of lead. This is an important thing to include. Tannin 10:39, 14 May 2005 (UTC)

Precautions

Doesn't seem to list any actual precautions that should be taken. -- eyrian

Simple, don't eat it. Lead is not nearly as toxic as the vast majority of other chemicals. Even if you did eat it, you'd be in more danger of intestinal rupture from lead chunks than lead poisoning.

Lead salts pose more of a danger, but even still, for most lead salts you'd need to consume large amounts for an extended period of time to have any ill effects.

Darrien 18:17, 2005 Jun 14 (UTC)

Good and well, but what about living on lead contaminated soil? I guess lead chunks aren't immediately dangerous, it's more a long-term environmental exposure type of problem, yes? Josh Parris ✉ 00:22, 15 Jun 2005 (UTC)

It depends on what kind of lead contaminated the soil. Any form of lead will leach into groundwater given enough time, but it would have to be a very toxic form of lead like an organometallic compound to pose any danger to someone just taking a stroll through the area.

Darrien 03:25, 2005 Jun 15 (UTC)

There have been a number of widely reported Playschool soil contaiminated with lead and shutdown type stories where I live; are kids playing in contaminated soil at any real risk? Josh Parris ✉ 03:48, 15 Jun 2005 (UTC)

I really can't answer a question like that without more information. Children *are* more susceptible to lead poisoning, but the media does have a history of sensationalizing stories such as these. Without hard facts, I can only say "it depends". If you have a genuine concern, I would recommend that you speak to a physician or toxicologist.

Darrien 03:14, 2005 Jun 16 (UTC)

Obviously no-one above has had the experience of finding out that your child has a high blood lead level. I have! Lead toxicity is a serious problem for children under 5 as it lowers IQ. The dangers should not be underplayed. Michael Glass 15:54, 27 April 2006 (UTC)

Fuel additive

Can somebody who knows more about it than me add some information on lead as a fuel additive? This is an odd omission. --WibblyLeMoende

Whilst I know nothing about it, I have added it. Josh Parris ✉ 07:20, 15 July 2005 (UTC)

Tetraethyl lead, perhaps? --24.80.110.173 06:47, 7 August 2005 (UTC)

Pencil Lead

According to the 'pencil lead' article, lead was never used in pencils, but graphite was instead mistaken for lead when it was discovered under a tree. I've read a book about inventions that would corroborate that story, and I somehow doubt lead would make enough of a streak to ever b e used to write with..

The pencil#history section says:

The prototypical pencil may have been the ancient Roman stylus, which was a thin metal stick used for scratching on papyrus, often made of lead. The word pencil comes from the Latin word penicillus which means "little tail".

But, for about 450 years pencils have had "lead cores" of graphite substances. Josh Parris 00:05, 16 November 2005 (UTC)

One book I read stated that molybdenite and graphite were used, but that molybdenite was mistaken for a lead mineral. It said that no lead was ever used. Lead solder (in contrast to lead-free solder) makes a streak, but it's much fainter than graphite.

Plumber

The word plumber comes from lead in Latin (plumbum). In Spanish, lead is plomo, and a plomero is a plumber. All this *leads* me to believe that pipes in old cities are made of lead!!! Are we drinking lead in New York and other cities with old buildings and utilities? Remember, it is said that one of the causes of the Fall of the Roman Empire was a general lead poisoning of its population, which was worst in the ruling class. Is it true that we are eating lead whenever we eat tuna fish or sardines? (maybe in all canned food?) Maybe there is some research about all this. Thanks.

I think that historically most pipes were made of lead. However they were sometimes made of hollowed out timber. I think that the problem of the Roman ruling class was not just lead pipes, but cosmetioc uses of white lead (lead oxide). I do not think there is any problem with modern tins; if there is with fish, it must be coming from the water they swim in or the food they eat. Peterkingiron 22:51, 18 April 2006 (UTC)

Lead solder is no longer used in cans. It can leach out and poison people who eat the food. An expedition to find the Northwest Passage by John Franklin in 1845 is thought to have succumed to lead poisoning after eating only canned food (There is some dispute; see the article on Sir John Franklin). The bodies were found to contain high levels of lead. I have never heard of a problem with lead in fish; are you thinking of mercury?

Lead smelting

The present article says nothing about

• how lead is smelted from its ore, either at present or historically. All I can see is an incomplete setction in Derbyshire lead mining history.
• how silver (a valuable impurity in lead ores) is recovered in the course of smelting, either currently or hisotircally
• other lead related industries, such as the production of white lead. Peterkingiron 22:34, 15 April 2006 (UTC)

Somebody's changed "smelt" back to "melt". I distinctly remember fixing that, but anonymous edits have been disabled (I can't be stuffed registering for Yet Another Bloody Website Account). Could somebody please change the sentence "It is highly malleable and ductile as well as easy to melt." to "... easy to smelt", as it should be? Ta. —The preceding unsigned comment was added by 130.194.11.64 (talk • contribs) .

Edit done, old protection lifted. Femto 14:36, 20 November 2006 (UTC)

I have a bit of a problem with the lead production section: It says (and this is supposedly referenced information) that during roasting the lead sulfide concentrate is converted to metallic lead. Lead concentrate roasting is an oxidative roast. PbS is converted primarily to PbO, and yes some amount of PbSO4 and lead silicates end up in the sinter. I say sinter, because the roasting is normally carried out in a travelling grate sintering machine. I was about to delete and correct the paragraph, but noticed that it's referenced. I don't have access to that (1949) reference. Can someone please check on this for me? I can counter reference my statements above, and I've been in a lead smelter and seen a Dwight-Lloyd sintering maching operating, preparing lead oxide sinter for blast furnace feed.BSMet94 20:21, 1 February 2007 (UTC)

I was the one who put that in about PbS roasting. The chemical reaction is documented in the next section. I will recheck the references tonight when I get home, but my recollection is that the quantity of lead metal that you get versus lead sulfate is depenent upon the amount of excess oxygen present. The Samans reference is indeed old, and perhaps modern lead smelting doesn't take advantage of this reaction anymore. I will quote the reference on this talk page and let you decide. Karl Hahn (T) (C) 22:02, 1 February 2007 (UTC)

On review of the Samans source, my-bad. I misinterpreted the list of sintering products. Inded, as BSMet94 has pointed out, the sintering is done with the objective of removing as much sulfur as possible, and hence is done with excess oxygen. The reactions list shown on page 250 does not show any metallic Pb as a product.

"The final sinter will contain about 52% lead [this is what I misinterpreted], 2% sulfur, 8% silica, 15% FeO, 3% lime and small amounts of other metals and oxides.

"Any of the following reactions may occor during roasting: [reaction list follows]"

I am going to fix the paragraph in the main article immediately. Karl Hahn (T) (C) 01:19, 2 February 2007 (UTC)

Good collaboration on that little topic! Thanks.BSMet94 04:42, 2 February 2007 (UTC)

I agree. However, we still need do with something on historical smelting processes, perhaps as a separate article. I am surprised to read that modern smelting is in a 'blast' furnace. 18th and 19th century smelting was in a reverberatory furnace; when was the use of blast furnaces introduced? The present blast furnace article is entirely about iron; if blast furnaces are being used for other metals, that article requires a further section. Peterkingiron 12:45, 3 February 2007 (UTC)

I just reviewed the Samans reference again. It has a diagram of the blast furnace, which is a dwarf compared to its iron-smelting cousin. It also says "the lead blast furnace is similar in construction to the copper blast furnace." It goes into detail about temperature, charge, and operation, as well as a reaction list. Samans does not say when this process was adopted. The reverberatory furnace is used, according to Samans, for refining after smelting. BTW I just updated the article here to list a little more detail about the waste materials from the blast furnace process. Karl Hahn (T) (C) 14:22, 3 February 2007 (UTC)

Primary lead smelting is almost universally carried out in blast furnaces. They are a very different design of blast furnace than that used for ironmaking, but the principle of operation is the same. I've seen one in operation. There have been a few other smelting furnaces developed for lead (e.g. QSL, Kivcet), but they haven't really replaced the blast furnace. To my knowledge lead smelting is not and has never been carried out on any notable scale in a reverberatory furnace, reverbs are used in refining for lead. Your book is right in that the lead blast furnace is similar in design to the copper smelting variety, but copper blast furnaces went out of common use by the 1920s. BSMet94 05:20, 4 February 2007 (UTC)

Lead burning color

I see several Wiki metal articles (Zinc, etc.) mention you can test for the metal by burning a sample of it and viewing the colour of the flame produced.

Does anyone know the colour of flame when burning Lead? —The preceding unsigned comment was added by Quatermass (talk • contribs) 17:46, 27 December 2006 (UTC).

Some sort of whitish pale greenish blue, descriptions vary... See here [1] for a spectrum. Femto 19:02, 27 December 2006 (UTC)

Flame test says pale green. RJFJR 18:06, 21 March 2007 (UTC)

Lead Should be hard as metal

Grown from the local gloucester boxing circuit Simon marcer grew up with the fighting name lead. He thought it was a sign of respect as "hard as Metal". But in fact his lack of knopwledge due to skiving chemistry at school meant he didnt see the irony that lead is the softest metal. —The preceding unsigned comment was added by Virtualwaster (talk • contribs) 10:24, 25 April 2007 (UTC).

Lead regulation

There should be a whole article about Lead regulation. Until then, all we seem to have are Lead poisoning and Restriction of Hazardous Substances Directive. The main Lead article does not give us figures on total global production/use; we don't know how it is changing annually, over decades. We have been using this known poison for thousands of years. In the US, lead plumbing is still in use, and we are so negligent as to use it to balance the wheels on our cars. How does Europe compare? What organizations are most active against lead hazards?-69.87.200.233 18:56, 4 September 2007 (UTC)

It took me about 10 minutes to identify a whole raft of sources on this topic at EPA: [2] [3] [4] [5] [6] [7] [8] [9] [10] [11] [12] [13], and so on. Also do a search on "lead pollution" or "lead production" or "heavy metal pollution" at [14] to find out what what's going on with lead regulation in Europe. Once you've done the research, please feel free to write some text in lead or create a new article for lead regulation. Please be sure to read and follow Help:Contents/Policies and guidelines when creating new text. Help:Contents/Editing Wikipedia will give you some useful info on how to edit. I also have a useful cheat-sheet at User:Karlhahn/usefulLinks. Karl Hahn (T) (C) 15:44, 5 September 2007 (UTC)

The regulation section of Lead poisoning should be big enough now to split off into an article. It is easy to find an overwhelming amount of material -- http://www.atsdr.cdc.gov/csem/lead/pb_standards2.html is a great place to start. But haven't found any non-US resources yet... And maybe there should be a redirect from Lead toxicity to Lead poisoning?-69.87.199.214 17:21, 9 September 2007 (UTC)

Production pollution

There must be pollution, danger, and toxicity associated with lead mining and production, currently. But there does not seem to be any info in WP about this. Please add such information.-69.87.203.198 11:57, 5 September 2007 (UTC)

Units for Density

I don't think the units for density for any of the elements are correct. Density is mass PER unit volume. the "per" means "/" not "•".

eg.  ρPb = 11.34 g/cm³. 

Maybe the "g•cm³" is a different way to write it, but I think it is confusing. Someone should fix that.

--Drew.wollman 16:22, 6 September 2007 (UTC)

Observe that the actual rendering is g•cm⁻³, which is correct (because of the minus sign in the exponent. Karl Hahn (T) (C) 17:04, 6 September 2007 (UTC)

Your right. I totally spaced the "-".--Drew.wollman 23:07, 7 September 2007 (UTC)

Reasons for reverting pourbiax diagrams

1. None of the recent additions by Cadmium (talk) are accompanied by any references whatsoever.
2. Chemistry phase diagrams do not belong in the health effects section.
3. It is not at all clear what the diagrams mean, especially the vertical "E_SHE/V" axis. The pre-existing descriptive chemistry section was targeted at the level of understanding a reader might have after taking a typical high school chemistry class. Much of the new material is at the level of an undergraduate advanced inorganic chem class. WP is not an advanced inorganic chem textbook.
4. Diagrams should be thumbnail size to the right of the text they illustrate. They should not be dominating the text. Readers who want a better look at a diagram will click on it.
5. Lead sulfate diagram has horizontal axis showing concentration of HS^– rather than HSO₄^– concentration.

A paragraph on lead (II) chloride complexes would certainly be a good addition. The graph is unnecessary though. All that is needed is text stating the existence of the complexes and the conditions under which they form. And it all needs have a reference. Karl Hahn (T) (C) 18:14, 23 September 2007 (UTC)

I would say, fork these sections directly into an own article, they are much too difficult for an entry level article like lead (I mean, the man in the street will type 'lead' to know more about the metal; this information is way to specialistic for this article). Hope this helps. --Dirk Beetstra ^{T C} 19:35, 24 September 2007 (UTC)

I think the diagrams and related information are somewhat useful, and even though they are a bit technical, I wouldn't prefer the complete removal of them. The question boils down to where the information would be best located. Many of Karlhahn's objections can be addressed without removing the information from this article (such as lack of referencing, diagram size, HS^– vs HSO₄^–etc.) Personally, I don't have an objection to having the diagrams in this article, but if others agree with Dirk that a separate article would be better, and I'd be content with that too. --Ed (Edgar181) 20:54, 24 September 2007 (UTC)

Additions testing and answer to Tannin

Former Analytical Chemist for test lab: environmental and industrial.

1. Usually analyze Lead via Atomic Absorption spectroscopy but occasionally by wet chem methods. Standard wet chem analysis of solder composition was PbFCl titration. Lead has a strong affinity for a single flouride, forming PbF+ which is titrated with Chloride (PbF2 is soluble). The dissociation constant for (PbF+)(Cl-) was on the order of Silver Chloride. Dithizone (1,5-Diphenyl-3-thiocarbazone) method (EPA sw846) for PPM determinations. http://www.woodrow.org/teachers/chemistry/1989/49heavy-metal.html see #4 for how Lead gets into fresh water shellfish. Today environmental Lead by Ion Coupled Plasma (or ICP). 2. Lead Oxide is used in Gold ore assays, much of the PbO subliming in the furnace. http://www.nbmg.unr.edu/comstockscience/fireassaying1.shtml 3. Study of children playing near major roads (High PbO and PbBr2 from combustion of leaded fuel, residue in dirt by roadside). Blood of kids with Parts Per Billion Lead had significant IQ lowering. The "biochemistry of lead poisoning" is an mechanism of gross lead poisoning in adults. The mental damage of heavy metals (Hg, Tl, Pb) in children is different. Interesting that the RoHS thing replaces Lead in solder with Silver which is actually more toxic in adults. 4. Pb3O4 is an oxidizer that was used to protect steel and iron, often used as paint on structural beams and ships (also barnacle protection).

5. to Tannin re: 204 - - - rem Earth is (theor.) 4.5E9 years old. see http://en.wikipedia.org/wiki/1_E17_s

20 years ago Pb204 was thought stable, but by rechecking previously previuosly considered stable isotopes with more sensitive instruments very long half lives can be detected. The standard surplus gas tube radiation detector that we had in high school science had a higher tick rate from backround (cosmic rays etc.)than from a sample of depleted Uranium (U238) 4.5E9 yr half-life.

As to differing half lives of isotope 204: I don't have my Chemical Rubber Handbook here, but I'm assuming your errant half life is synthetic Pb204m. The high energy ion bombardment that that is used to form isotopes may leave the isotope formed with excess energy above the ground state. Generally these metastable states emit the excess energy as a gamma photon hence Pb204m >> Pb204 + gamma.

6. add ref to http://en.wikipedia.org/wiki/Decay_chain page for origin of Lead isotopes

Shjacks45 04:44, 8 November 2007 (UTC)

Pencil Lead

This subject is discussed twice, both in the "Uses" and "Phrases" sections. Should it be consolidated? --Claygate (talk) 20:39, 22 June 2008 (UTC)

I removed the phrases section as it was just a trivia section that had no real justification for existence. Wizard191 (talk) 23:20, 29 June 2008 (UTC)

Lead mining in Wales

This section seems very out of place to me. It talks about a very specific occurrence of lead, whereas the rest of the occurrence section is much more general, which is they way I think it should be. Is there a different article where this would fit better? Or perhaps it should just be removed outright? Wizard191 (talk) 23:35, 29 June 2008 (UTC)

It does seem to lack Importance. I'll add the tag for the heck of it. Primalmoon (talk) 21:54, 16 August 2008 (UTC)

I think the right solution would be to fork this section into a separate article. The Derbyshire lead mining industry already has its own article, and I see no reason why there should not be others on other non-ferrous mining fields. Peterkingiron (talk) 15:18, 31 August 2008 (UTC)

Sounds good to me! --Wizard191 (talk) 15:21, 31 August 2008 (UTC)

Can lead be handled with bare hands?

Can lead be handled with bare hands? I've just done that and my hands became dirty so I have washed them quite thoroughly with water, and now I'm worried. ... Rfwoolf (talk) 14:46, 31 August 2008 (UTC)

This is not a forum. Please don't use it as one. --Wizard191 (talk) 14:50, 31 August 2008 (UTC)

I am seeking information I expect to find in the article. Rfwoolf (talk) 14:54, 31 August 2008 (UTC)

If you are not satisfied with the content of the article add to it. Don't come to the talk page and ask a question on here as though this is a forum to make a point. That's gaming the system. --Wizard191 (talk) 14:59, 31 August 2008 (UTC)

Or if I don't have the knowledge to actually add to the article, I could point out what I find missing or unclear in the article on the talk page. If I knew whether or not lead could be handled with bare hands a) I wouldn't have asked, and b) I would have put it in the article. Rfwoolf (talk) 15:05, 31 August 2008 (UTC)

Wikipedia is only as good as what its editors add. If you would like something added you have two options: 1. research it and add the info, or, 2. ask on the talk page to have the info added. You didn't do either of these. You asked a specific question about the topic of the article, but didn't ask to have that info added to the article. The point here is to phrase your questions/inquires correctly. As a secondary point, peterkingiron points out that the proper place for this info to be added is the lead poisoning article. --Wizard191 (talk) 15:26, 31 August 2008 (UTC)

Wizard191 I am choosing to disengage with you as I find you too unreasonable. Perhaps we will have to agree to disagree. There are probably hundreds of entries on talkpages on wikipedia added every day of people asking questions and pointing out what is unclear or missing from articles. That is what I have done and Peterkingiron has been a star - a true Wikipedian for addressing the enquiry - and perhaps ultimately the requested information will one day find its way either into Lead or Lead poisoning. If you think the way I phrased my enquiry was wrong then perhaps you could have been a bit more diplomatic, acknowledging that the Talkpage is indeed the place to point out issues with an article but then adding that I should perhaps rephrase it into a slightly different format. Instead you have accused me of "making a point", "gaming the system", and (before changing it) threatened to even block me. My attempts to reason with you seem to indicate that you are the type who hates to retract their statements or admit any margin of error, mistake, or wrongdoing. In such cases I will defer to you, You win. I'm wrong. You're right. I will never ask questions on a talkpage ever again. Thanks peterkingiron Rfwoolf (talk) 15:48, 31 August 2008 (UTC)

It would be useful to have a section added to the lead poisoning article dealing with this issue. My understanding (but without certain knowledge) is that handling clean lead is probably harmless. If the "dirt" was actually corroded lead, you need to take steps to ensure that you do not ingest it, such as thoroughly washing your hands (not merely rinsing them). However, I am not an expert and my advice may be unreliable. Peterkingiron (talk) 15:15, 31 August 2008 (UTC)

Disclaimer: what follows is not Medical Advice™, blah, blah, blah... That said: Rwoolf, don't worry, you won't get acute lead poisoning just from touching lead once. As for chronic poisoning, that's more likely to result from repeated exposure over long periods of time. So, if you handle lead every day, it would be a good precaution to wear gloves, have proper ventilation, etc. Washing your hands thoroughly after handling lead is also a good idea. To Wizard191, I can only suggest reviewing WP:BITE. Articles are very often improved thanks to the questions that people post on the talk pages, because such question can highlight omissions or lack of clarity. One final comment, however (to no one in particular): It is Wikipedia policy not to offer medical or practical advice, and there is consensus that Wikipedia is not an MSDS (material safety data sheet). Therefore whatever information is added to the article regarding Rwoolf's question must be tempered by these considerations. --Itub (talk) 09:15, 1 September 2008 (UTC)

Thanks for the input guys. Not that I handle it often I will now buy some gloves and a mask. I washed my hands about 2 times and shortly afterwards I showered, too, but was still a bit worried. :) Rfwoolf (talk) 15:45, 2 September 2008 (UTC)

Problem with exhaustion of lead supply cite

The citation entitled "How Long Will It Last?", supposedly backing the fact that lead supplies will run out in 42 years, doesn't seem to actually contain this information. The link to the article online is here:

http://environment.newscientist.com/channel/earth/mg19426051.200-earths-natural-wealth-an-audit.html

No info on the 18 years figure either. I'm concerned, because it would seem that if lead supplies are really so short, we would be seeing much broader recycling efforts, since lead production must start declining far before supplies are exhausted. More likely, I would imagine that the 42 year figure refers to the date where lead production will peak.