Don't get in the gold recycling business - you will lose your shirt. -- Will

On Tuesday 29 May 2007 00:08, Jan-Benedict Glaw wrote: Based on the auction price, it looks like the seller expects it to be somewhere between 1-2oz. Pat -- Purdue University ITAP/RCAC --- http://www.rcac.purdue.edu/ The Computer Refuge --- http://computer-refuge.org

Hi I just can't think how there would be 1-2 oz of gold in 100 lbs of scrap. Gold used in electronics is plated on. 15 to 30 mil is what I recall on most anything. By My calculations, that would be an optimistic surface area of 55 by 55 inchs of gold surface for 1 oz. For some old HP circuit boards, maybe. For just regular boards? There is a lot of gold in PC boards but in a 100 lbs of boards I don't think you'd find much more than about 1 foot by 1 foot of gold surface. That is a lot of gold but not an ounce. Calc: 19.3 g/cc for gold 1lbs = 454 g 1 oz = 28.375 g 1 oz au = 1.47 cc 1 cu in = 16.39 cc 1oz au = .0897 cu in at 30 mil 1 oz au = 3000 sq in = 55 x 55 surface. Most IC's are on a surface of about .0625 sq in. That would be about 50K IC's. Dwight _________________________________________________________________ More photos, more messages, more storage?get 2GB with Windows Live Hotmail. http://imagine-windowslive.com/hotmail/?locale=en-us&ocid=TXT_TAGHM_mig…

There is indeed often a large amount of gold on the leadframes and bond out wires. Even on many worthless looking plastic DIPs. About two years ago I had some scrap EMC memory boards for some sort of system, loaded with Oki 256K DRAMs. Plastic, boring looking DRAMs. If I flexed the board enough, the tops of the plastic DIP split and popped off the leadframes. Goooold......... -- Will

remember, the furniture industry used to, and may still to some extent (restorers even) use gold leaf for decorative purposes. The stuff is so thin - wild guess - somewhere between .0001 and .0003" thick - it floats in the air, and tares very easily. It's still gold, one of it's properties is that it can be spread awfully thin. Essentially they'd apply glue to the surface to be "gilded", allow it to get tacky, then apply the leaf with a brush, somewhat similar to a shaving brush (for applying shaving creme). ____________________________________________________________________________________ Get the free Yahoo! toolbar and rest assured with the added security of spyware protection. http://new.toolbar.yahoo.com/toolbar/features/norton/index.php

William Donzelli wrote: But all that *old* scrap is now gone from about the mid 80's. If there is so much gold there why is he selling them? PS. I never could see the the ebay sale the link was down so I just can see the boards in question.

William Donzelli wrote: I don't think scrap is the problem, just all the people who speculate on the price of metal is. Off hand base metals like copper and lead seem to be better $$$ than other stuff.

Not to mention that making a connector pin out of solid gold is *stupid*. Gold has rather bad mechanical strength as compared to more conventional metals, and is expensive; its only real benefit is its corrosion resistance, and all you need for that is gold plating. /~\ The ASCII der Mouse \ / Ribbon Campaign X Against HTML mouse at rodents.montreal.qc.ca / \ Email! 7D C8 61 52 5D E7 2D 39 4E F1 31 3E E8 B3 27 4B

Hey, someone bought the big ram pile.

--- Brent Hilpert <hilpert at cs.ubc.ca> wrote: They use solvents or whatever typically I guess, but the addition of a lot of heat might do it too. You can build a small gas furnace for probably much less then $100 USD. Theoretically the temperature will be limited only by the quality of the refractory cement used. Oi whatever. ____________________________________________________________________________________Take the Internet to Go: Yahoo!Go puts the Internet in your pocket: mail, news, photos & more. http://mobile.yahoo.com/go?refer=1GNXIC

--- woodelf <bfranchuk at jetnet.ab.ca> wrote: Gas burns much hotter...unless you're talking about *real* charcoal made from hardwoods. But you know what...gas still burns much hotter. My point was you could mess w/hydrochloric? acid and all that (wherever you'd find it - I know someone's going to point out how it could be commonly had, or maybe it's a relatively *common* thing to find)...or you could just burn off all the volatile gunk in a cheap furnace. But you'd have some steel (pins) left over. That'll melt too...at oh about 2800 degress Fahrenheit. Can't remember if gold melts at a higher or lower temperature. But at least you should be able to separate the gold from the steel. Or come to think of it maybe you could eliminate the steel before the barbecue. I'm not aware of a resistance element that'll go any higher then ~2300 degrees, that being enough to melt brass or prolly even pure copper. But the mints use magnetic induction (with some sort of coil thingee). But that requires and awful lot of juice I'm told. Like enough to light a city block... ____________________________________________________________________________________Sick sense of humor? Visit Yahoo! TV's Comedy with an Edge to see what's on, when. http://tv.yahoo.com/collections/222

der Mouse wrote: I don't know about alloys, but there are definitely *compounds* with higher melting points. Peace... Sridhar

--- der Mouse <mouse at Rodents.Montreal.QC.CA> wrote: Right, but I'm not so sure they're commonly available. If you go into one of these places that sell supplies for ceramics and whatnot, they should be able to order you a kanthal wire element probably for $15-20. You can build a table top brass melting furnace with one, but most casters don't like electric. I slopped together a unit a number of years ago, did absolutely no calculations, made the cavity too big (used a 5 gallon can for the body!), and the only brass I was able to *melt* was a 1/8" diameter brass rod. Melted a curve into it was about all. Anyway, if you want to mess with gold salvaging, I suggest gas. If that's even the right way to do it. Couldn't hurt to try if you have a bunch of scrap laying around. I hate gas (am skeered of it, less though then when I was younger), but it's clean, quick, hot, and thereby alleviates a number of the *problems* that go with using a resistance element furnace. ____________________________________________________________________________________ Need a vacation? Get great deals to amazing places on Yahoo! Travel. http://travel.yahoo.com/

On 30 May 2007 at 22:34, woodelf wrote: Very hot is the so-called "atomic hydrogen" torch--H2 is passed through a high-voltage arc and split into monatomic hydrogen which then recombines and burns. It's the exothermic recombinatin that really kicks the temperature up--about 3700C; the actual combination of the hydrogen with oxygen adds very little heat to the reaction. See: http://www.lateralscience.co.uk/AtomicH/AHW.html But for most anything else, oxy-acetylene is fine. A few years ago, I remember seeing a welding rig for jewelers that used electrolysis on water to create fuel and oxygen. The thing drew something like 10 amps at 240VAC and produced a very tiny flame. There was so little heat produced (although the flame temperature was pretty high) that you could pass your hand through the flame. IIRC, gold is usually deplated from other metals (and out of ore) with sodium or potassium cyanide. At least that's what I recall from reading about a "heap leach" gold mining operation. Cheers, Chuck

Chris M wrote: A similar compound they believe was in the paint of the Hindenburg. I remember something with a title like that in the late 1960's. They have not done *much* with rockets since then. Hopefully the X-prize may spin something off. Just don't count on NASA -- they spend $$$ on everything but rocket development. Now lets call it a day, get back to classic rockets ... err computers. Woodelf ------------------- cut here for email --------------------- bfranchuk AT jetnet DOT jetnet DOT ca

--- Chuck Guzis <cclist at sydex.com> wrote: Perhaps I'm in error, but I could swear I read 6000 deg. F. Probably in Linday's literature. That does seem kind of high, given that steel only needs 2800 degrees. ____________________________________________________________________________________ Don't get soaked. Take a quick peak at the forecast with the Yahoo! Search weather shortcut. http://tools.search.yahoo.com/shortcuts/#loc_weather

Sridhar Ayengar wrote: Yep peace. I would not to want to get you angry with your collection of interesting combustion-ables . :)

Alexandre Souza wrote: Mix them. http://www.youtube.com/watch?v=80Q3GgeeIVM Peace... Sridhar

couldn't resist... http://www.guzer.com/videos/thermite_car.php just cuz it was French. LOL LOL and http://www.guzer.com/videos/thermite_ice.php were those simply flower pots or crucibles? Why didn't they just pour a pile of thermite on top of the hood? ____________________________________________________________________________________ Park yourself in front of a world of choices in alternative vehicles. Visit the Yahoo! Auto Green Center. http://autos.yahoo.com/green_center/

"Oh the huge manatee!"

Geoff Reed wrote: But the one of the arguments from the news reels was the bright flames. Hydrogen + Oxygen does give a flame you can see. Also once you got your hole burning then does the hydrogen kick in.

Chuck Guzis wrote: Sigh ... I thought I typed *not* in their.

On 31 May 2007 at 10:19, Chris M wrote: You can melt gold easily with nothing more than a cow and a tree (Charcoal and bellows). Gold melts at 1064C, lower than the melting point of copper (1085C). Iron, by contrast, melts at 1535C. Cheers, Chuck

John Foust wrote: And just how will you extract your gold ... ?

I would be very suprised if any conenctor pins are 'solid gold' for 2 good reasons. The first is mechanical, gold is too soft a metal for that sort of thing. The second is economic, the reason for using gold is to prevent corroosion, and plating is as good as solid for that, and a lot cheaper. -tony

I've just been using EDAC516 series connectors [1]. The pins in those are hermaphordticv, They're fork-shaped, and fit together cross-ways.Of course the housings hold them in the approprtiate orientation. And yes, the pins I was using are gold-platedm but not solid gold [1] I needed a connector with 80 or so pins for the HP BCD interfaces. Other requirements were that it was robust, easy-ish to wore to a cable (so no 0.8mm inter-board connectors :-)), and likely to have been used for computer applications 30 uears ago. Since EDAC 516 connectors were used on the DOcumation card readers, I think they fit the bill :-) -tony