Non-Chemical processing ceramic cpu's commercially in Manila....

[Redders]

This last year I have done a bit of IT business with a man who has been reclaiming gold from IT components for about ten years. He does this in Manila in the Philippines.

With ceramic processors, they knock off the lids (and process separately), they break up the chips into large-ish pieces and incinerate in a cast iron crucible. The heat is usually from a torch which may be kerosene and air (to cut costs) but could be oxy-acetylene. They add lead and melt it into the mass. They skim off slag from the top and they fish out the ceramic from the bottom. The pins and the fine gold wire within the cpus melt into the lead.

The molten metal is cooled. Later, the metal is reheated and the gold migrates to the middle and can be clearly identified. The straight lead is carefully poured off. The gold bearing lead is treated with nitric.

He believes that some values are lost but this is how it is done by many small companies in Manila.

I told him that I would post this up on this site. I will show him any responses and ask him to respond to them.

 

[Harold_V]

You've been lead down a path, or you're talking with someone that doesn't have a clue.

I'd like you to consider a couple things, ----then decide the truth about the balance of what you've been told.

Lead and gold, either combined, or individually, weigh far more than ceramic materials, so such material would not be on the bottom, but on top.

Lead and gold, alloyed, will NOT stratify, let alone permit the gold to occupy any particular place in the mass, such as the center. That's total nonsense. Assuming any stirring at all, the gold should be somewhat distributed throughout the lot. When litharge is used to collect values, it is generally cupelled, leaving the values behind. To my knowledge, it is impossible to separate lead from gold via stratification.

Harold

 

[Redders]

Roly, he is called and I have spent quite a bit of time with him. There is no doubt that he is genuine sort of bloke.

I put it on here because I couldn't quite get my head around it. The ceramic being submerged was my fist query. I will communicate with him via emails and follow this up....

nice to communicate with you, Harold, I'll get back to you....

 

[goldsilverpro]

Doesn't sound right to me, either. There must be something you're missing. About 30 years ago, the US Bureau of Mines came up with a method to remove gold from the tin/lead solder that was used in wave solder machines to solder components to circuit boards. They melted it and stirred in some aluminum. The aluminum picked up the gold and floated on top of the solder. It was skimmed off and the gold was extracted from the aluminum. Lead fumes, of course, are toxic.

 

[Irons]

Try precipitating Gold out on Aluminum and you will get a purple color on the Gold that is an alloy of Gold and Aluminum. It drove early IC manufacturers crazy with Gold/Aluminum bonds going bad, hence the name Purple Plague.

Interesting technique.

http://en.wikipedia.org/wiki/Gold-aluminium_intermetallics

Gold-aluminium intermetallics are intermetallic compounds of gold and aluminium that occur at contacts between the two metals. These intermetallics have different properties than the individual metals which can cause problems in wire bonding in microelectronics. The main compounds formed are Au5Al2 (white plague) and AuAl2 (purple plague), which both form at high temperatures.

White plague is the name of the compound Au5Al2 as well as the problem it causes. It has low electric conductivity, so its formation at the joint leads to an increase of electrical resistance which can lead to total failure. Purple plague is a brittle, bright-purple compound of AuAl2. The process of the growth of the intermetallic layers leads to creation of voids in the metal lattice.

Other gold-aluminium intermetallics can cause problems as well. The compound Roberts-Austen's purple gold, is composed of 79%Au-21%Al, with a melting point of about 750°C. Above 624°C, purple plague is replaced by Au2Al, a tan-colored substance. It is a poor conductor and can cause electric failure of the joint that can lead to mechanical failure. At lower temperatures, about 400–450°C, an interdiffusion process takes place at the junction. This leads to formation of layers of intermetallic compounds with different compositions, from gold-rich to aluminium-rich, with different growth rates. As the denser faster-growing layers consume the slower-growing ones, cavities form. This process, known as Kirkendall voiding, leads to increase of electrical resistance of the wire bond and its mechanical weakening. When the voids are collected along the diffusion front, a process aided by contaminants present in the lattice, it is known as Horsting voiding, a process similar to and often confused with Kirkendall voiding.

All problems caused by gold-aluminium intermetallics can be prevented either by using bonding processes that avoid high temperatures (e.g. ultrasonic welding), or by designing circuitry in such a way as to avoid aluminium-to-gold contact using aluminium-to-aluminium or gold-to-gold junctions.

 

[goldsilverpro]

A long true story.

In about '72, I invented a method and formed a company, with a money partner, for the service of recycling all-gold plated, old type CPU, side-braze packages (mainly 40 lead) for reuse. These were rejected parts, in various stages of production. Most were rejected on final testing, after sealing.

I went to the Silicon Valley to hustle business. I hit about 10 huge electronics concerns, cold, and showed them before and after samples. Every company I went to was very eager to talk to me and they all gave me samples of their rejects.

I also found out that Fairchild Semiconductor had spent a lot of money trying to do this same thing and had failed miserably. There were also a couple of smaller companies that had worked on this, but their methods were Mickey Mouse and they produced unacceptable parts. I think they were the ones who got the patents that are mentioned below.

Purple plague was one of the reasons for rejection.

My biggest customers were Intel, AMD, and AMI. At the end, we were doing about 100,000 packages per week. We (1) Removed the lid and chip with heat and a vacuum probe and removed the bonding wires; (2) Chemically stripped (electrolytically) the gold plate and gold alloy brazes selectively without attacking the base metals (the crux of my invention). These base metals were Kovar legs and sealing ring, plus moly-manganese chip pad, internal traces, bonding fingers, and pads to braze the legs to. Also, silver/copper braze was used to attach the legs. There was also nickel plating under all the gold plating. I should mention that cyanide (the first thing I tried) wouldn't work because it attacked the copper and silver; (3) Replated the gold; and (4) Returned them to the companies for new chip attachment and reuse. Our recycled packages had a higher yield than new packages. We charged half the price of a new package. The new price of these same packages now is about $4 or $5, although there are far fewer of them used today. The extra gold we removed from the gold brazes (80/20, Au/Sn for the lid; about 96/4, Au/Si for the chip) nearly paid for our processing. At that time, when the companies put out a new chip, the early manufacturing reject rates were as high as 98%

The business ended in '74 (I think) when Nixon devalued (10%) the dollar twice and there was a 6 month dock strike. The electronics industry died. No parts could then be shipped to or from from the overseas assembly facilities. Right before the strike, a company in Texas promised us 100,000 parts per day. When the strike hit, they went down to 5,000 per week. We shut our doors. Oh well.

The same process can be used for high dollar ($10 to $1,000), all-gold, hybrid packages, which are used widely today in specialized applications. The process costs are about the same as on the cheaper packages and the 50% charge still applies. Lower volumes, lower setup costs, much higher profits, on the hybrids. I set up a small hybrid process in '80. We rented a booth in a ISHM show (International Society of Hybrid Microelectronics). We laid out about 20 different before and after packages on black velvet and got over 100 electronic companies that were interested in our wares. However, at that time, my main business was gold and silver refining. 1980 was also the year that the PM prices went through the roof. We sometimes had 20 people waiting in line, when we opened the door, to sell us gold and silver scrap. There just wasn't any time to concentrate on the packages.

As far as I know, no one else has ever come up with viable process to rework these packages. There are a couple of patents out, but they require a lot of hand work and are far slower, much more expensive, and inferior to mine. I didn't patent my process but it's still in my head (and in my head only, I think). My process is still very viable.

About once a year, I feel a need to rant about this. If only that frigging dock strike hadn't happened! Oh well.

 

[Irons]

I remember some of those old white ceramic 40 pin dips that Intel used. They had so much gold on the pins, you could literally shave it off with a knife.

Wouldn't it be nice to have a few tons of those.

 

[goldsilverpro]

There were white ones and purple ones. We also did 14, 16, 18, 24, and 28 lead sidebraze packages. There was about 50 to 60 millionths of an inch of gold plating on them. This is the thickness required to prevent degradation and discoloration at die attach temperatures. The gold plating is 9999 pure. The same packages are used today with the same amount of gold. You can see them being offered for sale on the websites of package manufacturers - Kyocera, etc. I don't know where they're used today. Probably on military applications, etc. I think they (and the hybrids) are still the most reliable, long term, package made.

New side braze, hybrids, etc.:
http://www.ntktech.com/products_scd.asp?categoryid=13
http://www.chelseatech.com/packages.htm
http://www.spectrum-semi.com/index.html
http://www.addisonengineering.com/HTML/ceramic-packages.html
http://www.amkor.co.kr/products-sidebraze.html

New Hybrids, etc.:
http://www.twmtech.com/hybrid.html
http://www.inseto.co.uk/products/micromaterials/centuryseals-hermeticpackages.shtml

Old stuff:
http://www.cpu-collection.de/?tn=0&l0=md&l1=1975&l2=Intel#C8080A
http://cpu-museum.de/?m=Intel
http://www.chips.5u.com/

I have, literally, had tons of them. Ah, the good old days, when a package was a package and I was right in the middle of things.

 

[Irons]

I know the ones of which you speak. The type i'm referring to look like the leads were hot-dipped in Gold and you could cut off a curl with a knife.

 

[Redders]

Hi Redders,

If Harold V concluded that I don’t have a clue as to what I have seen over the years, he has to go there himself and observe it.

I am not going to argue over something petty which I know is true.



If his reasoning is sound, why would anybody lie over trivial matters such as primitive procedures in recovering gold from obsolete IT equipment?

Why would someone lead you down a path over nothing? Your guy makes hasty conclusions. Or he must have a very high regard of himself

and thinks that anybody who contradicts his beliefs is a liar.



From your description of the procedure, what he should have questioned as amiss is “incinerating in a cast iron crucible” because

the iron will melt with the material being recovered. The crucible is made out of a type of clay, not iron, which sometimes cracks during the

firing process and has to be cooled and redone again



Obviously, your Harold V hasn’t tried this procedure of recovering gold from processors because of the following errors in his statement:

1) that the molten mass will not “permit the gold to occupy any particular place in the mass such as the center”. Well it does everytime!!!

2) that the “ceramic” in the processors will stay on top of the molten alloy because the gold and lead, either combined or individually,

weigh far more. (I suppose, Mike, if the processors are finely grounded, the “ceramic” material will float, but you did say in your

email that the processors (chips) are broken up into large-ish pieces, in which case they stay at the bottom of the crucible.



May I suggest he try the procedure first and if he is wrong, apologize. All the best, Roly


(Harold, Redders, here, I am not stirring you both up for fun. I respect both of you and I know that there is no ******** with either of you two good men).

 

[goldsilverpro]

Redders,

When I read your first post, I thought something was missing. Are you sure they're not adding something to the lead to collect the gold, such as aluminum or maybe zinc, as in the old Parkes Process? That would make more sense to me. Sometimes, people making money from a process don't give you the complete story. In fact, when I was a refiner, I was often guilty of this.
http://en.wikipedia.org/wiki/Parkes_process

I know you will get a little stratification when metal slowly solidifies. For this reason, metallurgists have developed drilling patterns to use when sampling bars. When you vacuum tube sample impure gold in the melt, you have to stir it well first to eliminate any slight stratification. But you're talking about a fairly clean separation using nothing but lead. I have some vague thing in my mind that says that some sort of separation is possible by controlling the temp. to a gnat's ass and thereby solidifying only certain parts of the melt, while other parts are kept liquid.

I don't doubt that this is somehow being done in the Philippines. I am very interested in how it works. However, it seems that your explanation leaves a lot to be desired. You gave no details at all on how to really do it. You didn't give us any info on why it worked. The statements you gave made no technical sense at all. I know you're smarter that that. On this forum, no one is going to accept a vague blanket statement without calling you on it, especially if it makes no technical sense at all.

And, just out of curiosity, why did you say they used cast iron, when you knew they used clay?

If you don't know why it works, please, at least, enlighten us more on how it works.

 

[Redders]

I am, in fact, a 'newbie' and I was just wanting to take a bit of an active part by putting something up here that would be interesting to you 'old hands'. I will copy this thread again and email it to Roly and I will see if he will come on here and discuss it with you.

I have to add that Roly is the owner of the business and he spends most of his time purchasing. He employs the gold reclaimers in Manila but they have more gold-recovery expertise that him.

I will contact him now and give him a link and my password and see if he will join us.

(by the way, thanks for all of your posts, I appreciate yours (and others).....

 

[aflacglobal]

Ok, this is going to sound crazy, but i think their might be some madness to his method. Or is it the other way. Dam voices.

He said they raked the hulls out the bottom and skimmed the slag off the top. This sounds exactly like a sweat furnace he is describing here.
I sweat furnace is used to reclaim metals from such things as copper and aluminum motors, Irony aluminum transmissions and alternators. Ect.

The term sweating is used because the material is brought up to just above the melting point and the metal begins to melt or sweat like butter from the objects.

Now this helps that maybe.

The clay pots they are using is also basically refractory. He said they cracked and had to be repair frequently. This sound about right .

Next i guess we need to look at bouncy and density of metals. ( Chris you got this one )
I know some what how they behave in aqua solutions, but molten solutions behave different. Remember we learned from the guy that wrote me from South America that they melt catalytic converter material in a induction furnace and the metals all concentrate at the center of the mix. That's how they would concentrate thousands of pounds of material into several KG.

I'm wondering, He said they leach ( Basically ) melted the crushed up processors if you really think about it. Using heat instead of liquid.

Could the copper maybe that’s in the material form a bond like in solution.
He said they reheated it. If you only raised the temperature up above the melting point of lead would the copper or gold complex settle.

I remember a demonstration in high school where we took mercury and put quarter in it. They floated. Why ? The mercury is a liquid and the quarters being solid should sink. Hummmmmm Density. :idea:

Just some thoughts.

Oh yeah, He's using something more than just a regular fire. Maybe some bellows ?

 

[goldsilverpro]

Redders,

That would be great to get Roly on the forum. I'm really pleased that you are taking this well. We would hate to lose you.

Don't get mad at Harold. He is often blunt and he's not going to let anything slide by (Don't ask me how I know this!). But, I've gotten to know him pretty well and I can assure you that his heart's in the right place. His only purpose on this forum is to help people.

 

[Redders]

I also feel good about Harold. We swapped emails for a fortnight as he nursed me through the production of my first proper button. He has the runs on the board and he can be a cranky bugger if wants to be.... no bother, here.

 

[Harold_V]

I know some what how they behave in aqua solutions, but molten solutions behave different. Remember we learned from the guy that wrote me from South America that they melt catalytic converter material in a induction furnace and the metals all concentrate at the center of the mix.

Yes, perhaps, but with an induction furnace. The force that would cause levitation of the metallics would be absent in the process mentioned. There is no reason for the gold to concentrate in any place in particular -----not in lead----nor can you, or anyone, present a reason that might suggest a reason it would. Fact is, if the charge mentioned was to be melted by induction, it would be stirred exceedingly well, with the gold perfectly distributed within the lead.

I've been told on many occasions that it's real easy to separate gold from other metals. All you have to do is melt them, and the heavy stuff will sink to the bottom.

It just ain't so, folks, so get that out of your head. Once alloyed, most metals are NOT easily separated from one another.

Harold

 

[Harold_V]

1) that the molten mass will not “permit the gold to occupy any particular place in the mass such as the center”.

Well it does everytime!!!

Words are cheap. I deal with facts. I assume you can provide a picture, at the very least, of this phenomenon, and explain why it violates known principles?

2) that the “ceramic” in the processors will stay on top of the molten alloy because the gold and lead, either combined or individually,
weigh far more. (I suppose, Mike, if the processors are finely grounded, the “ceramic” material will float, but you did say in your email that the processors (chips) are broken up into large-ish pieces, in which case they stay at the bottom of the crucible.

Maybe I'm not fully understanding this, in part because it's not clear who's quoting what, but if the implication is that the pieces of ceramic do anything but float, this conversation has gone over the edge. Breaking a substance into smaller parts does not change its specific gravity-----and anyone that has enough sense to come in out of the rain knows that light things float on heavy things, regardless of size, assuming they don't create buoyancy through displacement (such as a steel-hulled boat). The exception, of course, would be if the metals were being sweat, but that has not been claimed at this point. It's unlikely that is the case, for the sweat furnace constantly runs molten substances to a holding vessel, which would have to be kept fluid until completion of the run. Even then, I'd like one reason why the gold would accumulate in the center.

Understand this, anyone that cares enough to read my words. I am a person of fact, and am not easily caught up with ******** claims. I have recovered gold by known means, and have seen the results of efforts of those that think they are clever and can violate the rules and succeed in their quest. To this point, I have seen nothing here that makes sense aside from melting items with lead to effect a recovery of values. The magic gee wiz claims of gold seeking the center of a common mass makes no sense-----none------and violate everything I've learned about the principles of metals in my many years of not only refining, but machining and foundry work.

It is not incumbent on me to pursue a matter that makes no sense. If you'd like me to have a different opinion, address the issues I've raised, and present some evidence that the asserted claims work. Otherwise, leave me out of this discussion. You asked my opinion, and I gave it. Right now, I'm calling ********.

Harold

 

[Harold_V]

He said they reheated it. If you only raised the temperature up above the melting point of lead would the copper or gold complex settle.

No, they would not, and there's no reason for them to do so. They are also not simply copper/gold complexes. They are a sum total of all elements that are included, assuming they will willingly alloy. You have to understand that molten metals are much like water in that they have considerable solvent capabilities.

Lead is used for two reasons, which I feel can be substantiated by GSP. It is introduced to an assay sample as litharge, which is reduced to elemental lead upon heating, liberating oxygen, which then oxidizes other substances, oxidizing them. The molten lead then collects miniscule traces of values that otherwise might not have agglomerated and reported in the assay.

Once molten, the lead, which may never achieve the melting point of gold or platinum, dissolves these elements, along with others, and forms an alloy. Once combined, the eutectic point is established and all elements will then melt at that temperature when reheated. You can not (normally) selectively melt one metal from another.

I remember a demonstration in high school where we took mercury and put quarter in it. They floated. Why ?

That's a no brainer. The specific gravity of silver is lower than the specific gravity of mercury-----so the lightest substance floats on the heavier one. I think I said that already. Not only does it float on the mercury, but it is slowly dissolved by the mercury as well. Given enough time, the entire coin would be consumed by the mercury, assuming there is enough mercury present to hold in solution the amount of silver and copper present.

Oh yeah, He's using something more than just a regular fire. Maybe some bellows ?

Any maybe the hair from three frogs and the hide from a black cat?

We're men of science here, not witch doctors. The source of heat, unless it's an induction furnace (which introduces strong magnetic forces to the heat), makes no difference.

For your consideration: The idea of gold accumulating in the center of lead is not impossible, but highly unlikely. Zonal refining works on that principle, but under well controlled conditions. If it was as easy as it's been presented, it would be difficult for foundries to pour castings that were homogeneous. They don't suffer that fate.

Harold

 

[aflacglobal]

If it was as easy as it's been presented, it would be difficult for foundries to pour castings that were homogeneous. They don't suffer that fate.

That makes sense. :wink:

 

[goldsilverpro]

LEAD REDUCTION

I haven't looked at the chemistry of fire assaying for quite awhile but, concerning the reduction of litharge to lead metal, and the subsequent release of oxygen, here's what I remember.

The heat is not what causes the litharge to give up it's oxygen. This is shown in the scorifying process. One purpose of scorifying is to reduce the weight of a lead button to a convenient size so it can be cupelled. This is done by melting the lead in a shallow wide dish, called a scorifying dish. The oxygen in the air oxidizes the surface of the lead to form litharge, lead oxide. The longer this is done, the more the lead oxide will be produced and the less the weight of the lead metal that remains at the bottom of the dish. The point is that the heat does not re-convert any of the lead oxide back to lead metal. Also, all of the precious metals that were originally in the lead metal, before scorification, are now retained in the lead metal (most probably, very uniformly) that exists, after scorification. None goes into the lead oxide phase.

Reduction of the litharge, and the subsequent release of oxygen, requires some ingredient in the fusion melt which will act as a reducing agent. Commonly, this would be carbon, sulfides, or iron. Ideally, when assaying electronic parts, the fusion should result in a 30 gram chunk of lead. If no reducing agents are inherent in the sample, an exact amount of lead can be reduced by adding an exact amount of some ingredient that contains carbon. Sugar, flour, or charcoal are commonly used. I learned to use sugar when I started. If I remember right, 1.4 grams of sugar (depending on the brand) will produce 30 grams of lead. I think that the ancients used lees, a substance that settles out in wine. A couple of times, I forgot to add the sugar. I ended up with no lead button - zero. All of the litharge had gone into the slag.

CERAMICS AND LEAD

In my days, I have assayed many 100's of PM containing, ceramic electronic component samples. With no exceptions, the ceramic pieces, large or small, floated above the lead. If I remember right, the ceramic even floated on top of the slag which was on top of the lead. If any ceramics had sunk into the lead, this would have made cupellation of the lead impossible.

THE REFINING THRILLA IN MANILA

I'm no longer a betting man (unless it's on my pool game) but, I would wager that zinc (or maybe aluminum) is being added to the lead to get the gold out - the old Parkes process. This may be done through sleight of hand. It's the only thing that makes any sense to this whole thing. It sort of fits into the original explanation. It's a fairly dangerous process since, at the end, to get rid of the excess zinc in the silver, it is evaporated off into the air by heat.

POOL - A MISSPENT YOUTH

In case there are any pool players out there, here's an article I wrote that may interest you. That's my brother in the picture that was taken a couple of years ago. My brother and I play Corners every Friday night on the six pocket pool table in his basement (for only a measly dollar a game). Playing Corners on a six pocket table is kinda like kissing your sister but, all the 2 pocket tables are gone from the pool halls. I could play it on the 2 pocket Corners table at the Elks lodge but, every time I go there, I seem to get into trouble, at least in my own mind.

http://onepocket.org/Corners.htm