AR metod for Ceramic CPUs...

[SasaK]

Hi everybody,

I am reading the forum for a month already and have read Hooks book all about gold -few times, and made a lot of notes. I have now something like 70 CPUs (all kinds) so I am slowly planning to do my first refining of 10 ceramic cpus...

So I would be very greatfull if you could advice me a little before my first refine...

Here are few things which are important for my case:
-I will do refining outside on a windy day in countryside so my process must be fairy quick (within 16 hours) because I would like to avoid camping outside for days (weeks) . For this I decided to use AR method.

Poor Man's AR I can not use because it is difficult for me to get sodium nitrate...

Basically I plan to follow Hooks procedure for "Rolled, Filled and electroplated gold, and gold scrap containing soft solder" -page 67.

Any advice to speed up the proces ? Some step to take out or to include ?

You guys never boil CPUs or pins in Sulfuric Acid, I wonder why ? There is a Pb in solder.. right...

Hoke is using a lot of time on settling the sediments (days) and then pouring of the liquid. I plan to use finest quality filter paper and vacum filtering to avoid spending time on settling all together? Is this sound idea ?

Is there any big diference between Poor Man's AR and clasic AR metod with 65% Nitric Acid ?

Thanx...

 

[Harold_V]

You guys never boil CPUs or pins in Sulfuric Acid, I wonder why ? There is a Pb in solder.. right...

Sulfuric won't eliminate lead. It does precipitate lead as lead sulfate, however, so if you have lead in solution, sulfuric can be beneficial.

Hoke is using a lot of time on settling the sediments (days) and then pouring of the liquid. I plan to use finest quality filter paper and vacum filtering to avoid spending time on settling all together? Is this sound idea ?

In general, no. When a solution isn't eager to settle, it often won't filter, either. Key to success is creating solutions that lend themselves to either process. One of the things that is often beneficial in that regard is to incinerate, then digest the solids in hot HCl. A couple rinses in water (allow the solids to settle, then siphon off the solution) will generally eliminate troublesome substances, so the values, once dissolved, can be filtered without issue.

Harold

 

[SasaK]

Herold, thanx for replay... I was reading many of your posts and I personally decided to follow up your detailed washing procedure and idea to keep everything clean from start...

Here are the pictures of the CPU-s which I plan to use for my first refine:




They are toatal 10 ceramic CPU-s:
9 AMD Durons from 1998
1 AMD Athlon from 1999 (something like that)

I hope they will have good yeald...

If I decide to use Poor Man's AR metod, instead of adding Sodium Nitrate (which I dont have), can I add small ammount of 65% Nitric Acid to HCL and CPU mixure? I am planning to do this but I wonder how much is not to much? I do not want to start desolving gold,and on other hand I do not want to use to lilttle Nitric Acid and have to pour off HCL to many times...

Thanx...

 

[patnor1011]

Herold, thanx for replay... I was reading many of your posts and I personally decided to follow up your detailed washing procedure and idea to keep everything clean from start...

Here are the pictures of the CPU-s which I plan to use for my first refine:
View attachment 1



They are toatal 10 ceramic CPU-s:
9 AMD Durons from 1998
1 AMD Athlon from 1999 (something like that)

I hope they will have good yeald...

If I decide to use Poor Man's AR metod, instead of adding Sodium Nitrate (which I dont have), can I add small ammount of 65% Nitric Acid to HCL and CPU mixure? I am planning to do this but I wonder how much is not to much? I do not want to start desolving gold,and on other hand I do not want to use to lilttle Nitric Acid and have to pour off HCL to many times...

Thanx...

You have a lot of study ahead. If you put Nitric in HCl you create AR so any pouring off HCl will be pouring off gold as gold will dissolve.

If you plan to do that 10 pictured CPU your yield will be in 0.1 up to 0.4g range. Depend on your skills. I highly doubt that there is more than 25-35$ worth of gold.

 

[SasaK]

Patnor, to study and learn is OK and normal... and before pouring off I will test solution for gold... this I know...

But my idea was like this:
Since in Poor Mans Ar method is added small amount of sodium nitrate in diluted HCL to form small amount of Nitric Acid in the solution (HCL to Nitric ratio is very high and not like in AR), maybe I could do the same by directly adding small amount of nitric acid, instead of sodium nitrate??? Pour of and repeat proces 3-4 times (according to Poor Mans Ar method). Or maybe it does not work this way... ?

If I could not get some sodium nitrate on my hands, maybe I should forget Poor Mans method and boil the CPUs in nitric acid... But how long will it take for nitric to completly desolve base metals in 10 CPUs?

Yield is that low, 0.01g til 0.04g per CPU ?
OK, never mind ... I do this just for training anyhow. .this is my first refine...

Thanx...
Sasa

 

[patnor1011]

I am not an expert by any means but I am here long enough to know that most of problems are created when people try to substitute something or alter process. If I would you I would start with Nitric. In that way you keep gold in a plain view and base metals will dissolve. Then proceed with purification of your gold. As I said before do not expect too much of a gold from 10 CPU. It is a good way to learn by doing small scale batches but result will barely cover cost of your chemicals and time invested in this.

 

[samuel-a]

Sasa

Pat has a very good and important point.

yes, if it were me i would use AR, but for someone that is just starting, this process may create a lot of confusion.
First you must acquaint yourself to the working process with the different concentrations of gold solutions and with different levels of contaminants.
It's not simple to control contaminants when dissolving everything with AR, therefor, hard to undersand the dynamics and qustions like "where the hack is my gold?" start to pop up.

for example, with 10 ceramics and say 0.3 g yield.
you will probably use around 200-300 ml of dilute AR, filtering will add more 100ml h2o, so now you are at 300-400ml dirty solution, starts the drop... but hay...
it's not like in the videos on youtube, nothing is happening "what the h%#% ?" but gold is actually is dropping, just you can't see it... bla bla.. you get my point :mrgreen:

Treat base metals (with nitric/AP) first as Pat suggested, keep your eyes on your gold through the process, until you are ready to dissolve it and just it (of course some BM will be left to be dissolved with the gold, but that's not the point.)

BTW - Poor man's AR and AR are same thing and with same results. The only difference is in the way nitric is introduced to the solution.

Good luck and stay safe.

 

[SasaK]

Thanx guys... You all gave me some very good advice...
I will now try to buy chemicals and equipment and slowly prepare for the refine...

I'll keep you posted how it went...

Thanx
SasaK

 

[SasaK]

Hello everyone...

What is the best way to treat thermal paste on this CPUs? Should I wash it with soap, wipe clean with paper or ignore it totally ?

I plan to do flowing things on CPUs:

-take out plates with blow torch
- NaOH boiling
-boiling in water
-Nitric bath...
-H2SO4 bath
-AR
-dropping with SMB
- another AR
-washing
-melting

I am not sure in which of this phases thermal paste will go off. .so I would like the most to remove it totally before starting the process..

Thanx

 

[Claudie]

I usually just wipe it off with a paper towel. Water doesn't do much to it.

 

[glondor]

I believe many types of thermal paste contain silver. I do not clean it off, rather I just run it through the process and filter it out on the second filtration.

 

[dtectr]

The paste will likely have silicone as an additive, if not the base.
Silicone's job in formulas is to keep things from sticking together.
It also adds a measure of heat resistance, keeping the compound flexible.

The first characteristic is the one you don't want in solution. You will likely wind up with fine metal floating in a solution that refuses to settle. Remember, you want your gold particles to agglomerate, find each other and then settle together in one mass.

Many people clean the compound off with alcohol & paper towels. Coming from the sanitation industry, I frown on that as final treatment - its virtually impossible to get all the residue off of anything, regardless of the cleaner used, as you smear it around repeatedly with a towel.

I use Awesome!, a very concentrated alkaline detergent with very few additives, and a scrub brush. After rinsing thoroughly, with a separate brush, I scrub them with with Bon Ami cleanser and, you guessed it, its own brush and a final rinse.

This sounds like it takes a long time, but it doesn't - a few seconds per CPU. Arrange them assembly line fashion.

Please note: Some frown on the use of any and all detergents in refining, but I believe they have their place if you eliminate the residue properly.

The second characteristic keeps incineration from completely eliminating the silicone, as it is highly heat resistant. Anti-seize compounds for high heat applications use as their primary ingredient - silicone, without the added fillers, which will break down in that environment.

Keep this in mind as well, please - I am still very new at this myself, and my recommendations are based on my brief experience as a hobbyist refiner.

Good luck!

 

[SasaK]

Thanx for advice....

What I did at the end is that after taking of the leads with blow torch, I just wiped off the paste with some soft paper and it seamed to made a good job...

But now I have another dilemma...

I have done refining of the above processors (20 pcs total) but only half way trough..

What I did is following:
-I did 1h boiling in 30% HCL to remove leftover solder.. It did a fine job...
-Washing in 3-4 times in hot water to remove HCL...
-Boiling for 1h in 65% Nitric to loosen pins (legs). It did also very good job because after 1h all the legs were on the bottom of the beaker so I could easily take out the ceramics...
-Then I started to boil legs in new fresh Nitric to remove base metals.. But this was taking me 4-5 hours, with changing of 4-5 batches of nitric and it only did something like 50% of legs... Then I run out of gas and went home...

Now I still have to boil further more in nitric to remove the rest (+/-50%) of base metals, but I start to wonder did I do something wrong ?
8-10 hours of boiling in Nitric to remove base metals from 20 Ceramic CPUs (all AMD Durons) seams to me little to long ?
Am I doing something wrong ?

Any feedback/advice/experiance on this one ????

Thanx...

Sasa

PS.
Au foils floating in Nitric solution inside a transparent plastic bottle....a beautiful site

 

[patnor1011]

I would say that using 65% nitric is counter-productive. It is recommended to dilute nitric with water. Reaction will be much faster. I do not boil pins in nitric as dissolving base metals produce enough of heat and beaker become very hot during process. I use 30% HNO3.
There is iron in legs of your processors.

 

[SasaK]

@patnor...

OK patnor, so you recomend I should dilute my Nitric to be 30%.. this make sense. .I was reading about it.. and no heating. .but still what do you think about 8-10 h for 20 processors. .is this still to long ? Will it be less if nitric is diluted.. and should I replace it as soon as it becomes dark brown/black.. or I should wait until all feezing/boiling stops ?

Thanx...

 

[patnor1011]

It takes much less time and I replace nitric when reaction is stopped. I used that last time on about 500g of pins from motherboards and it took about 4-5 hours and I changed nitric 0.5l about 6-7 times. It was just kinda testing batch.

 

[SasaK]

And what about steering.. ?
I noticed that majority of the legs with base metals fall on the bottom of the beaker, and only few fly around feesing, desolving... Do you steer and how often ?
I was steering from time to time, but I think that if I steer all the time then I will be exposed 4-5 hours to toxic fumes and this is not good for my health.. Also it is not easy to stear 4-5h

In my last refine, my "acid resistant" glove on the right hand was totally dissolved because it was above the baker with glass rod steering very often...

Is there some trick or nice procedure in this ?

 

[patnor1011]

Some people use magnetic stirrer but I just stir when I put fresh acid in and then after while... Not much often as I have a lot of time...

 

[dgr]

-I did 1h boiling in 30% HCL to remove leftover solder.. It did a fine job...
-Washing in 3-4 times in hot water to remove HCL...
-Boiling for 1h in 65% Nitric

Are you saving this Nitric? My understanding is that free chlorides aren't 100% washed away. Any free chloride will dissolve gold to AuCl in the presence of nitric acid. Harold has commented on this a number of times and at least in my thread he recommended roasting between HCL and HNO₃ washes. Doesn't his wash procedure go over this?

 

[SasaK]

You are right dgr,

After HCL and washing, when I was putting first Nitric I saw that solution was turning light yellow... So some Gold was lost in this way... But I was expecting this and I did it with purpose...

This is my first refine and I do not care so much about total amount of gold.. I want to go trough the process of removing base metals and AR process and later dropping gold with SMB and washing procedures...

I plan on my second refine to take more care about ammounts of chemicals, and ammount of gold on the end of process...

So wish me luck guys...

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