Pre 1940 Lead

[simonds]

I read an article awhile back that stated pre 1940 lead was very valuable. Has anyone heard anymore on this? I have asked several people, including midwest refinery. No one has any information for me. Thanks

 

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[Davisdog]

The only thing that comes to mind is Linotype. Linotype is a lead alloy that was used in printing presses. It now is much in demand by folks who cast their own bullets.

 

[blurr]

I read an article awhile back that stated pre 1940 lead was very valuable. Has anyone heard anymore on this? I have asked several people, including midwest refinery. No one has any information for me. Thanks

Search in the "what is it" section. Someone found a small bar of old lead. From what I remember, they said that the lead found back in the 40's and before was valuable because it didn't give off some sort of "rays" that newer lead does. I think it was alpha rays if I remember right. Also thought that they talked about it being worth more than silver. Sorry no definate stuff


John

 

[Siegfried Schlagrule]

some folks like old lead because it is now possible to extract the gold and silver that was impossible to get back then. exanimo, ss

 

[Bigcypresshunter]

low-alpha lead http://forum.treasurenet.com/index.php/topic,37951.0.html
http://forum.treasurenet.com/index.php/topic,15932.0.html

 

[momule55]

Gee, I guess Civil War bullets would qualify for this? I know there are relic hunters that have 100's of them,
common ones. This would beat trying to sell them one at a time..........and worth it. I have heard of a tale
of a wagon load of lead ingots being abandoned by the confederates near me...I must do more reaserch!!

 

[Bigcypresshunter]

"Lead-free soldering, originally started as an environmentalissue, is evolving rapidly into a business survival tool for the worldwide electronic industry. Promising lead-free solderalternatives for surface mount assembly applications includeeutectic Sn/Ag, eutectic Sn/Cu, Sn95/Sb5, eutectic Sn/Bi,Sn/Ag/Cu, Sn/Ag/Cu/X, Sn/Bi/Ag/X, Sn/Zn/X, andSn/In/Ag/(X). However, for wafer level area array solderbump interconnects, most of those options fall short in terms of fatigue resistance. Sn/In/Ag/(X) appears to be superiorwhen compared with Sn63/Pb37, as demonstrated bySn/In/Ag/Cu. For applications involving high lead solders, no solder alternatives have been developed yet. While theindustry is advancing toward being finer, smaller, lighter, and faster, wafer level packages using area array solderinterconnects is suffering from the soft error due to alphaemission from the lead in the solders. Although lead-free solder alternatives for eutectic Sn/Pb are virtually free fromalpha emission, the continuous dependence on the use of high-lead solders for C4 applications indicates that the challenge of alpha emission from lead-containing solders will persistregardless of the lead-free move of the industry. Thischallenge is getting tougher with the rapid advancement of IC design toward further miniaturization. Low alpha lead can be obtained from cold lead ore, old lead, and laser isotopeseparation process, with the latter having potential as a long term solution. The price of those low alpha lead is veryexpensive when compared with the regular lead. Due to theincrease in I/O density, requirement on alpha emission levelmay soon move from LC2 to LC3 level. The supply of lowalpha lead for wafer level interconnects does not seem to be an issue.Table 4. Price of low alpha lead or solders.Alpha Emission Rate(count/cm2.hour)Product TypePrice ($/lb)Note<0.5Ingot10LC1<0.05Ingot50-150LC2<0.02Sn63, type 5 & type 6 powder1050-4050LC2<0.01Ingot90-190LC2<0.01Sn63, type 5 & type 6 powder1140-4400LC2<0.005Ingot220-360LC3<0.002Ingot80-150LC3, old Pb<0.001Ingot310-500LC3<0.0006Ingot680-1150LC3"
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ACKNOWLEDGEMENTThe author would like to express sincere gratitude to Dr.Joseph Fjelstad at Tessera, Dr. David Angst at TCAD,Paradiso Coskina at Fraunhofer Institute, Dr. Hugh VanderPlas at Hewlett Packard, and particularly to Dr. Paul Totta at IBM, for their valuable advise and comments on the low alpha solder issues. The author would also like to thank Dr. Benlih Huang at Indium Corporation of America for his extensivework on the Sn/In/Ag/(X) investigation.REFERENCE1. National Center for Manufacturing Sciences, "Lead andthe Electronic Industry: A Proactive Approach", May,1995.2. E. B. Smith III and L. K. Swanger, “Are Lead-free Solders Really Environmental Friendly?”, SMT, p. 64-66, March, 1999.3. N.C. Lee, “Lead free soldering – where the world isgoing”, Advancing Microelectronics, Vol. 26, No. 5,p.29-35, September/October, 1999.4. Frank Gibbs, “Pb Free Interconnect”, NEMI Lead FreeMeeting, Chicago, May 25, 1999.5. B.L. Huang and N.C. Lee, “Prospects of Lead FreeAlternatives For Reflow Soldering”, in Proc. ofIMAPS’99, Chicago, October 28, 1999.6. NEMI internal communication.7. J.A. Slattery, et al., “Lead-free alloy containing tin, silver and indium”, US Patent 5,580,520; Dec. 3, 19968. J.A. Slattery, et al., “Lead-free alloy containing tin, silver and indium”, US Patent 5,256,370; Oct. 26, 19939. S. Yeh, “Fatigue resistant lead free solder”, US Patent5,938,86210. P. Elenius and S. Yeh, “Lead Free Solder for Flip Chipand Chip Scale Packaging (CSP) Applications”, inProceedings of IPCWorks ‘99, Minneapolis, MN, S-03-2-1 to 6, October 23-28, 1999.11. Private communication with Paul Totta, IBM – Fishkill, NY, July 21, 1999. 12. Universal Instruments test data on voiding performance of flip chip underfilling process, 1998.13. J. Lau, T. Krulevitch, W. Schar, M. Heydinger, S.Erasmus and J. Gleason, “Experimental and AnalyticalStudies of Encapsulated Flip Chip Solder Bumps onSurface Laminar Circuit Boards”, Circuit World, Vol. 19, No. 3, 1993.14. M.W. Roberson, “Soft Error Rates in Solder BumpedPackaging”, 4thInternational Symposium and Exhibition on Advanced Packaging Materials, Braselton, GA, March 15-18, 1998.15. Private communication with David Angst, December 20, 1999.16. Peter Bokhan, “Secular Equilibrium”, Pure Technologies literature.17. Electronic Engineering Times, June 21, 1999.18. Private communication with Joseph Fjelstad, May 14,1999. 19. Private communication with Rick Jensen, representativeof SRL, on testing data on no alpha lead for alphaemissions by IBM, IICO, Johnson Matthey and PacificNorthwest National Laboratory, December 9, 1999.20. A. Chance, “A Bizarre Rumor”, internet communications, February 2, 1996.21. Steve. Berry and Sandra Winkler, "Flip Chip MarketExpanding to Meet Speed, Performance Demands", Chip Scale Review, p.6, 11/12, 1999.
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[Bigcypresshunter]

Regular scrap lead generally sells for .030/lb. Antiquity lead would get much more. I dont know the alpha emission rate of Civil War bullets. If you scroll down to Table 4, it shows the price per lb. depending on alpha emission rates.

http://72.14.203.104/search?q=cache...f++"low+alpha+lead"&hl=en&gl=us&ct=clnk&cd=20

 

[Sheldius]

If you are trying to get low alhpa lead, then the lead must have been SMELTED more than 60 years ago. The smelting into relatively pure lead would remove any trace elements that decay to Lead 210(and elements that decay into all the other lead isotopes). Lead 210 can't easily be seperated from Lead 204, 206, 207 and 208. Lead 210 is the only radioactive lead isotope.

Lead ores can contain all these isotopes of lead. Lead 210 decays (emits beta particles) to become Polonium 210. This decay of lead 210 has a short half life of 22 years. Polonium 210 decays (emits an alpha particle) to become lead 206. That half life is 0.3 years. So it goes away quickly (1/64 left after 2 years). Thus the bottleneck in getting low alpha lead is the half life of the Lead 210.

So after 66 years, only 1/8 of the lead 210 is left. After 132 years, only 1/64 would be left. Older would be even better. That is low enough not to mess up the more and more senestive computer electronic switches lead is used in. Another big factor is how much lead 210 was in the ore to start with. This can vary by a factor of 10.

How can they tell? They put the lead in a alpha detector for a few months and record the emissions.

I don't know who you would sell it to, but it costs a bundle to produce. I wouldn't be surprised if it is worth much more than scrap value. See below.

http://www.reed-electronics.com/semiconductor/article/CA163876?pubdate=1/1/1999

I work with lead isotope analysis for my PhD archaeology project (Roman lead curse tablets) in case you are wondering why I know/care.

 

[Bigcypresshunter]

Great information Sheldius. 8)