# Processing Black IC's - The wet way.



## samuel-a

This method is also known as wet ashing, a highly dangerous process which should only be attempted by an experienced operator, with all of the proper safety gear and apparatus. 
Otherwise, DO NOT follow this process !

----------------------

Jaun Nailed it in this post: Black IC's - a look inside
Since the method i used was unveiled and is indeed a very dangerouse process, i decided to share the entire process that i did, both to unveil the 'mystery' and make sure anyone trying this will keep himself *SAFE*.

The background to this process.
I my post, i said i had an: "ah ha moment"... 
I was sitting in my lab and looking at my plastic buttle of conc' H2SO4, when i bought it, it was white, after several monthes it got very dark inside, that was the moment i remembered someone here on the forum mentioned that conc' H2SO4 strip the plastics off its elemental composing atoms, only to be left with black carbon, which gives this dark color.
At the time, i was busting my had around the black plastic type packages IC's and how to process them...
That was me 2+2 moment, since i have done wet ashing before with old filter papers...

So, i figured, if it takes couple months to "ash" the plastic in the buttle... imagine how fast will a HOT acid work...

I began experimenting and this is the process i came up with:

- IC's are covered with Conc' H2SO4 and the vessel is covered with watch glass (or condensation apparatus).
I came to learn that for each pound of IC's, i'll need a approx 1 liter of conc' acid.
Solution level should not exeed half the volume of the vessel !

- Slowly heated to 90° C (194° F) and left that way for 30 minutes. 
This is a precautionary step to prevent too violent reaction and maybe a boilover.
The epoxy resin (Bismaleimide-triazine epoxy) will begin to disintegrate alsmost immediately.

- Then, heat is ramped up to 240°-250° C (464°-482° F) for one hour. 
At which point, white Sulfur Trioxide fumes are noticble. I don't think i need to mention *HOW DANGEROUS SO3 gas is*. It is one step away from becoming sulfuric acid, all it needs is water, it can find them in you mouth and lungs!
The solution at this point is a black thick slurry and very hard to actually see any reaction, but it's happening.

- The solution is allowed to cool back down to ambient temp' while still on the hotplate (do not handle it while hot, reduce the risk of a mishap), this takes a good 2-3 hours.

At this point, all that's left in a solid state (other then carbon in a slurry and colloid form) are metals such as gold (wires), the silicon waffer and copper "skeltons" (in case memory chips are processed). I'll address that later.

- Slowly and carefully, water is added to the acid to double the volume.
I know what you are thinking, but, At this point, there's very little acid left to react with the water, but of course you can choose to do so the other way around.
Once diluted, is allowed to sit for 5 minutes or so.

- The bulk of the slurry is decanted slowly to a 5 gallon bucket, carefully leaving anything that had setteled in the vessel.
The process of dilution and decantation is repeated until all of the black carbon slurry is gone.
Of course, you will notice the gold wire, it's impossible not to!

Most of the wires will stay attached to the waffers, those that come loose, will quickly agglomerate. BUT, some will still be left to fly around, they do settle, but you must give them the chance to do so. This is why it is instructed to wait before decantation.
If you see any partially dissolved IC's, fish them out with a tweezers, wash them and throw to the next batch.

- The next step is dependant on which type of IC chips were processed.

In the case of N/S bridge and square IC's:
Mostly silicon waffers and gold wires are left, direct AR / HCl-Cl could be used.

In the case of memory chips, there will be a lot of copper along side the waffer/wires.
One can eliminate the copper with nitric acid or AP.
I chose to melt everything down to form a Copper anode.


Jaun mentioned in his post that he successfully used conc' Nitric acid, I find it a little bit scary, for even the slightest chance of producing an explosive compunds.
I might be wrong of course, but whan you think about it, hot conc' nitric is just as dangerous and can cost 5-10 times more then the sulfuric does.


I was very reluctant to discluse this process before due to 2 main reasons (never had inentions on selling it):

The first, is the obvious direct danger of utilizing boiling sulfuric acid...
i can't stress the safety issue enough.
Eye protection or a full face mask should be used while handling.
Long chemical resistand gloves should be weared at all time.
The process should be done in a fume hood or out side away from peoples and pets.
Extreme care sould be enforced while handling conc' H2SO4.
A bucket of sodium bicarbonate is recommended to have around, just in case.

The second reason, is the indirect waste hazareds.
As you probably realized earlier, this process produce a fair amount of of waste solution, one lb of chips may create up to a gallon of waste.
I consulted with two very smart folks on this subject, both of which holds a degree in chemistry (Lino1406 ans sucho).
We all concluded that the resulting waste solution will probably not hold any toxic organic/organosulfur/aromatic compounds and can be safely discraded to the drain.
The only treatment step that i do think should taken in this regards, is to place a sheet of steel to displace any Cu in solution.
Any input from you on the waste solution subject is more then welcomed.

I know this process can help A LOT of peoples here, but *PLEASE, use all the safety measurements* mentioned above.
It's not worth to loose the palm of your hand, your foot, sight or even your life for so and so grams of gold.

Hope this helps, DO share your thoughts, comments and experience.

----------------------

This method is also known as wet ashing, a highly dangerous process which should only be attempted by an experienced operator, with all of the proper safety gear and apparatus. 
Otherwise, DO NOT follow this process !


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## skippy

Bravo Sam, thanks for giving such a detailed example of the dangers.
And thanks for sharing such a potentially useful technique.


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## samuel-a




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## philddreamer

Thank you Samuel!

Shalom! 8) 

Phil


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## samuel-a

Thank you skippy and phil.

I reckon this process will be best suited, economy wise for N/S bridge chips and square IC's...
less for memory chips.

I'll leave my yields out of this post.


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## ericrm

wow thank you
i know i no good in english but im shock that you give your info just to keep everybody safe
i dont know you, but now i respect you at a higher degree than many poeple i know
thank you to be a man of honor


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## arthur kierski

please Sam,when you say conc sulfuric you mean 98% or half volume ,that is:50%h2o-50% 98%h2so4------- i understood full strenght 98%----no water
thanks 
Arthur


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## samuel-a

You understand right Arthur.
That is 98% concentration.


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## skippy

Sam, I know I'm going to give it a try, I have to see myself what your pictures show. Really cool.


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## Geo

thank you sam!! 8) this may have its dangers but it is much safer than what i was doing.

good job on the research and i just would like to say in general, job well done.


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## jaun

Hi Sam

Great post. Sorry for high jacking your post, but I thought you were never gonna tell your secret.  

Like I said: I am using 55% nitric and it costs the same as cons. sulphuric here in SA.
And of course the safety issues is the same, it’s hot acid.
You got me worried about the explosive compounds now ??? :shock:


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## bswartzwelder

Thank you, Samuel. While I do not plan on using your method in the foreseeable future, I now knoe where to look. You are a class act.


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## hfywc

my hat's off to you...thank you kindly sam!


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## lazersteve

This method is very dangerous yet effective. Nice photos Sam.

I briefly mentioned the reagent for dissolving epoxy several years ago here on the forum:

Removing Epoxy Encapsulation

As I always say, there's not much that is new now days on the forum.

I will add that a much safer set up would be soxhlet extraction of the epoxy using this reagent. Trust me when I tell you that you don't want to be around 300+ degree celcius sulfuric acid with an open top reactor. A watch glass is not going to make much of a difference, if any. I have a few large ( 71/60 and 55/50 ) soxhlet rigs purchased especially for this type of reaction. Refluxing the water with the SO3 should help to reduce the fumes that escape the vessel and also allow for extraction of a much larger mass of epoxy with a given smaller quantity of concentrated sulfuric acid. Careful temperature control of the condenser and reaction vessel are critical to containing the SO3 gas safely. Proper handling and scrubbing of any off gases is also very important.

*Careful heating and cooling of pyrex glass is critical when working with these extremely dangerous reagents (eg. hot concentrated sulfuric acid) at high temperatures. If your reactor breaks, there is a very high probability that you are going to get hurt.* Fused quartz glassware would be a much better choice for use with this reagent and temperature.

Steve


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## samuel-a

lazersteve said:


> As I always say, there's not much that is new now days on the forum.



I guess so Steve...
That is why i never claimed the "invention" :mrgreen: , though, i must say, i have looked around for long time, both on google and here on the forum and never found your post or other information regarding the above process, maybe i didn't looked hard enough.

It seems like you didn't explored this avenue further since your old post in the link, or did you? maybe you could share some experience on the process.

Your tips and and safety notes are spot on. Also, I would very much like your input in regards to handling the waste solution.
I hate to think someone may harm the environment or get in trouble with the authorities over this promoted process.

Thanks


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## goldsilverpro

Sam,

The process of using hot conc H2SO4 to break down organic materials is called "wet ashing" and it's been discussed a few times on the forum. What you are doing is nothing new. You've just applied it to something different. I've been using it since the 60s mainly for analytical work in small quantities. It's too dangerous to use for larger amounts (been there, done that). Even the small quantities that I normally used can be very dangerous if you don't know exactly what you're doing. I toyed with using it, at one point, to break down gold-bearing ion-exchange resins in large volumes, but dismissed it due to the inherent dangers.

Hot conc. H2SO4, is soooo dangerous that I am considering deleting this thread. I would strongly suggest that no amateur try it. There are better ways to handle those parts - incineration, for example.

Please don't make a video of this.


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## lazersteve

Sam,

I for one was not set up to test the therory back in 2009 when I posted the link cited. I have tested it on a small scale myself though (see link below). The link is also not the only time the forum has discussed the use of hot sulfuric for dissolving epoxy. I found mention of the use of hot sulfuric acid as a reagent for dissolving epoxy numerous times via google around 2007 for the first time so I'm by no means claiming it's my 'invention' either. I knew of the post cited only because I remembered posting it myself. Other safer epoxy solvents have also been discussed, the one that caught my eye was known as Dynasolve 185 and is discussed in the post at the bottom of page one in this old thread:

Dynasolve 185 Epoxy Dissolver 

A link in the above thread has a member who got his hands on a 55 gallon drum of the material.

Check out these other Dynasolve Products

For this type of scrap I currently prefer crushing and leaching with AR after the solder is removed with HCl as mention in the above cited thread from 2010.

I haven't explored the waste disposal aspects of the reaction as I feel there are safer and better routes to the same results.

Steve


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## Geo

the post you linked had a reply from Quest42know above it.this is what i was using to break down the epoxy.it is very dangerous and i would never recommend anyone use a flammable liquid like that.even though it did break down the plastic,it did not dissolve it even when heated.before anyone throws a hammer at me,in my defense i would set my hot plate at the end of a 100' electrical cord with a GFI so i could basicly turn it on/off at a distance.the process sam describes IS very dangerous and i understand that any newcomer or beginner can see this as a way to process these cleanly without understanding the danger.but there are those among us that have and will deal with far worse and i for one think the post should remain as long as the dangers and safe handling are highly stressed.


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## samuel-a

Chris, Steve

I tend to agree with you both.

As i said above, i was very reluctant sharing this process, and still am in disagreement (with myself) about it.

I never had any plans on posting a video of the process on youtube or at my website.
The main reason i did post it here, is that other member had reported his success with this process, so i felt kinda obligated to both share and warn.

If it's up to you Chris, i think it will be a wise on your part to delete this whole thread and the other posts made by the other member.
I will not be offended in any way. And pretty sure the other member will not too.

I know that we are all big boys and responsible to our own choices, but...
The very last thing i want is someone to get hurt by something i have suggested.

Again , Thanks for all of your comments.


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## butcher

Sam, good post, but I see where someone who is not aware of dangers involved or Half ashed studied, could get hurt badly from this.

This is one process that has been discussed before but has not been recommended, and in fact has been discouraged, because of the dangers involved.

Sometimes it is better not to post some things.


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## glondor

G.S.P. gave me a fairly strong warning about a year ago when I asked about wet ashing filters. I paid attention to it. Thanks Chris. Just a question before this thread goes away. 

What would happen if sulfuric acid at working temperatures described in this thread came into contact with wood. Would the wood catch fire? Would you have a burning wood/ acid fire on your hands to deal with? 

Can this process be done in a different manner such as it would be rendered safe? (safer) IE: over an extended period of time at room temps VS such high heat? Is high heat critical to wet ashing? Will room temp Sulfuric disintegrate the carbon over time.?


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## glondor

Sam. Just a note. Too bad the process is so dangerous. Your results are beautiful, A recovery dream. The good stuff is right there for your eyes to see. Would be a great method for determining yield per pound except for the carbonized fleshy bits if you screw up. 

A proper protocol and process could be developed but the cost for a home refiner would be very high. Good job on the experiment. Once again your results are fantastic. I fear someone is going to try this and get hurt.


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## hfywc

quick question...to increase the concetration of battery acid to make it suitable for cell use, one has to boil down the acid to 1/3 of its volume, right? so, how is the danger different from wet ashing?


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## lazersteve

hfywc said:


> quick question...to increase the concetration of battery acid to make it suitable for cell use, one has to boil down the acid to 1/3 of its volume, right? so, how is the danger different from wet ashing?



Sorry to say, but if you have to ask this question this method is not for you.

Be safe and use incineration followed by crushing.

Steve


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## Rodthrower18

Has anyone tried the MEK mentioned towards the bottom of the dynasolve thread? If I can find it locally I'll definitely post up my results. So far no luck, just a bunch of substitutes that equate to being ethyl acetate, which will evaporate much slower I just have no clue if it will actually WORK(doubtful since most substitutes do less work for more $).


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## philddreamer

I tried some months ago MEK on PCB's trying to get rid of the solder mask, nothing happened. I have different black chips & IC's in MEK for the last 3 weeks, & they were not affected either. 
I got my MEK from Home Depot.

I think I'll be incenarating.

Phil


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## Geo

i didn't want to come out and say it but,the reply i made above concerned the use of MEK.i would BOIL the black plastic chips in MEK.WARNING:unless it is your intention to make a massively explosive situation do not ever attempt what i just said.it is dangerous and fool hardy.i have alot of land away from everything and only endangered myself and tried to minimize that danger as best as i could.the plastic would become soft but never did dissolve which was my objective.i still wound up incinerating the material anyway.


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## niteliteone

lazersteve said:


> hfywc said:
> 
> 
> 
> quick question...to increase the concetration of battery acid to make it suitable for cell use, one has to boil down the acid to 1/3 of its volume, right? so, how is the danger different from wet ashing?
> 
> 
> 
> 
> Sorry to say, but if you have to ask this question this method is not for you.
> 
> Be safe and use incineration followed by crushing.
> 
> Steve
Click to expand...


The jenie is already out of the bottle :shock: 
Deleting the post does not remove the infomation from those that have already seen it. 

I feel that this needs a better explanation so those that do not understand can understand.

Some do not understand what hot concentrated sulfuric acid does to organic compounds. :shock: 

I lack the ability to say it in a diplomatic way that most people can learn from without feeling scolded or worse, like wanting to try it just to see what I am talking about.
Can someone elaborate on what happens when things go wrong. Graghic details would also be good

I'm sorry Steve,
Tom C.


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## butcher

I would not try to stuff any genie in a bottle, but I also would not like to hear of a member or anyone else, just reading a couple of lines on the intranet (our forum). Mangled for the rest of their life. 

When we have safer and proven methods to use instead of wet ashing.

We could write up all of the procedures and all of the safety concerns, and all of the pictures of when and why things go wrong, why you should not do them in your basement, when making explosives, but that would not help a mother who's son read some of the instructions, disregarded warnings and crippled himself for life.

That is just how I see this, no argument I see your point mine just differs.


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## philddreamer

I'm trying to post a pic of a person with an acid burn on his foot.

Phil

P.S. It worked.
Deleted the picture; added the link,

http://www.bing.com/images/search?q=acid+burns&view=detail&id=53750CAFB0203C2689CC2CFC23A4A992AAF2A977&first=0&FORM=IDFRIR

Sorry for the graphic depiction.


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## Geo

i too understand both sides.consider some of the processes we do on a regular basis,if done correctly there's still a fair amount of danger involved.why deny information such as this and promote others that have the potential to be as deadly.its an age old argument about censorship.its not the information that's dangerous but the person that doesn't heed the warnings of others more knowledgeable.instead of suppressing the knowledge, give detailed instructions on how to and the dangers of the process involved plus all the equipment needed.make it understandable to the novice that this is an advanced process, not to be attempted without first accomplishing all the processes listed in advance and only with approved equipment.give people a chance to decide for themselves if they can be responsible with the information provided.


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## niteliteone

butcher said:


> I would not try to stuff any genie in a bottle, but I also would not like to hear of a member or anyone else, just reading a couple of lines on the intranet (our forum). Mangled for the rest of their life.
> 
> When we have safer and proven methods to use instead of wet ashing.
> 
> We could write up all of the procedures and all of the safety concerns, and all of the pictures of when and why things go wrong, why you should not do them in your basement, when making explosives, but that would not help a mother who's son read some of the instructions, disregarded warnings and crippled himself for life.
> 
> That is just how I see this, no argument I see your point mine just differs.



No argument, Complete Agreement

What I was trying to get at is as long as this post stays up (not deleted) we should try to spell out the dangers so someone can't come back and say *"why didn't you warn me that ..."*

Personally, I would prefer for this post and the related post that talks about this process to go away or at least be hidden some way.

Just my opinion
Tom C.


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## glondor

I think those who know the answers are very reluctant to take on the responsability of instruction in this process due to the very real danger involved. The level of concern suggests to me that there is an order of magnitude jump in the possibility of serious injury above and beyond our regular processes. We should not consider some one not wanting to carry the burden for some ones misguided mistakes as censorship. All the instruction and care in a tutorial can not stop inattentive or undisciplined web surfers from making mistakes and hurting themselves or others. We have heard from professionals who would only use this method under very controlled conditions and with very small amounts. We should respect the ones who know and let this thread die. I think in the interest of safety for the members this thread should be 
Deleted.


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## oldgeek

Here is a link to another graphic picture of a burn from Sulfuric Drain Cleaner.

http://www.chemaxx.com/acid3.htm

The entire site is a great read, and shows how things can go wrong so easily.

Make sure to check this one out too. Fascinating stuff. I have spent hours reading all of them.

http://www.chemaxx.com/explosion16c.htm


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## jaun

I agree with Sam and the others, delete it, both of them. Someone is gonna hurt themselves, its not worth it.

I tried to delete my posts from the other thread, but can’t. Please delete them.
Thanks


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## nickvc

I must admit while this is a fascinating thread I feel the dangers outweigh the advantages.
I can think off only one acid more scary than hot concentrated sulphuric.
Perhaps delete the thread but post a locked thread about the dangers of wet ashing just incase it can be accessed from elsewhere, it seems to be alluded to on the net, with a warning in large red lettering pointing out why we don't advise it's use especially for the home refiner and the need for extreme caution by the professional.


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## lazersteve

I feel the gory photos should be linked to via hyperlink, not embedded in the text of the post.

Very graphic.

Steve


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## qst42know

I think this is much like keeping a gun in your house and not having a long talk with your children. Don't think for one minute they won't find it and the ammo no matter how well you hide both.

Far better to have the talk than to wish you did.


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## ericrm

my opinion is to delete this post
what ever the way you think about it,it is a bad idea to keep it.
i will tell you why in my opinion we should delete this post
i f we take the fire arm as a comparison, in canada we have less fire arm than the us but also less accident,the reason is simple ,it is not the fact that you teach your children to use a gun that will make them hurt themself ,it is the fact that is an UNVOLONTARY ACTION that will lead to an accident.
if you didnt understand what i means ,you can teach as much you want about sulfuric acid,nobody will be stupid enuf to put his finger in... even if it happen only one time in a tousand when the beaker slip/crack/broke/boil(or whaever isnt suposed to happen) somebody will catch it by reflex... now say that we are 200 to know the process,risk are low for an accident, but with forum 5 000 000 poeple know the process 1in 1000 x 5 000 000
TO ME THE RISK OF UNVOLONTARY INCIDENT ARE HIGHER TEACHING SAFETY WITH THIS METHOD THAN JUST HIDDING IT
also if im not convincing enuf 8.99 for h2so4 and a mason jar over an hot plate,i will assure you that someone will try it,and the mason jar WILL broke.
anyway this is my opinion


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## qst42know

Show of hands, how many members are here on the forum because you get the whole truth as opposed to the half baked B.S. you find anywhere else on the web?

Here you get what works and what doesn't, whats safe and what isn't.

Those that proceed once they have all  the facts, you weren't going to save from themselves anyway.

Aren't those that concentrate their own battery acid for the cell doing the exact same thing?

Anyone want to try and push mercury back in the bottle, or do you openly discuss the safe use, or alternative methods?


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## publius

I am here to learn. I take personal responsibility for my actions. I want all the safety tips I can stuff into my head. I vote to keep this thread as is.

Additionally, I have posted, as have others, about the dangers of relying on a respirator when using NHO3. Others have warned of the dangers of Cyanide compounds and processes. 

sulphuric acid can cause horrid burns and as noted, damage to lungs and eyes that's almost immediate. Cyanide can cause instant death.

I would rather know of the dangers and make my own choice to use a process or not. 

Keeping this treat and others like it will benefit rather than hurt the members here.


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## niteliteone

I was first taught the process of wet ashing in my science class in 7th grade. (1975) We were shown the proper ways to do it as safely as can be done.
Now 35 years later I see it can be used to process IC's.
Don't know why I didn't think of it sooner.

But after seeing Patnors process I see it as a safer process for most people than this one. Especially for most people who have not had formal training in handling strong acids. 
In my opinion nitric acid is much more dangerous than sulfuric at any temperature and we give all kinds of warnings about the nitric fumes. They can kill you without leaving a visible mark on you. 
Why don't we ban all talk of nitric :?: 

This process has a place on this forum but people must take proper precautions themselves. Now that the proceedure is made public we need to talk about safety, not should we just delete it or not. 
This is about the same as the process given for recovering values from filters and not much different than concentrating acid for the gold cell, where we are actually given instructions how to concentrate the acid and be safe. 

I would rather see proper safety taught than to keep quiet and let people learn the process without proper instruction. Keep the topic, just give full instructions that include safety.

Just my opinion
Tom C.


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## samuel-a

niteliteone said:


> I would rather see proper safety taught than to keep quiet and let people learn the process without proper instruction. Keep the topic, just give full instructions that include safety.



I have tried to cover every angle in regards to safety in the original post.
Steve added some more notes later.

If you can think of anything else, do share it with us.


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## philddreamer

I vote to keep it. 
It has been explained very well, by the experts, the pro's & con's of the process. 
I don't think I'll be using the process, I'll incenarate; BUT, anyone that does, knows that will suffer serious consequences if something goes wrong. We've ALL been warned!

ALL the processes we do for recovery & refining the PM's ARE extremely dangerous!

Kindly,

Phil


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## patnor1011

Reverse electroplating involve hot concentrated sulphuric too. Fumes can burn your skin not to mention lungs too. I do not consider this process as viable for doing bigger amounts of chips due to risk associated. However if you have tens of kilograms of chips and want to use this process there is one way how to make it much safer. I had discussion with Sucho and he told me that he would consider using this method only when performed in reactor made from titanium - no risk of breaking. It is some kind of special titanium alloy. 
So my advice is do not try it if you do not have proper set up to perform reaction in safe way. Dont forget sulfuric fumes can burn your skin in the same way as direct contact.

Btw. did not we mentioned "Do NOT boil acid" countless times?


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## lazersteve

One major difference is that the sulfuric acid in the stripping cell doesn't ever reach 250C+ and does not emit thick white clouds of gaseous SO3 like the reaction described above does. Hot acids are all bad, but 250C+ sulfuric acid is especially nasty due to the copious amounts of thick white SO3 that is produced. 

Steve


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## publius

publius said:


> I am here to learn. I take personal responsibility for my actions. I want all the safety tips I can stuff into my head. I vote to keep this thread as is.
> 
> Additionally, I have posted, as have others, about the dangers of relying on a respirator when using NHO3. Others have warned of the dangers of Cyanide compounds and processes.
> 
> sulphuric acid can cause horrid burns and as noted, damage to lungs and eyes that's almost immediate. Cyanide can cause instant death.
> 
> I would rather know of the dangers and make my own choice to use a process or not.
> 
> Keeping this tread ad others like it will benefit rather than hurt the members here.


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## niteliteone

publius said:


> I would rather know of the dangers and make my own choice to use a process or not.


 8) 8) 8)


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## 27182

My two cents from the peanut gallery.

This is a familiar dilemma in education. 
Do educators have a responsibility for their students' safety after they've gone on to do whatever it is they will? Certainly.
Will some person see this thread someday and attempt this method? Almost certainly.
Will one or more of those hapless individuals harm themselves, or worse, another? It's a possibility.
Does responsibility lie upon those in this thread who've published the information, along with appropriate warnings? I think not.

In my opinion it is worse to omit the information; here's why. As someone said earlier, this cat is out of the bag so to speak. If one looks hard enough, or thinks about it long enough, they will wind up with this information in one form or another. Intelligent people are curious. Better that they should have the information from knowledgeable sources than by discovery or from lesser sources.

The alternative is to teach a subset of what is known, leaving the responsibility of learning the most dangerous parts of their craft to the individual, even discouraging questions. 
People, companies, and institutions think/hope that they can avoid being held accountable (and they sometimes can avoid financial responsibility) by simply dis-avowing any knowledge of the subject, dismissing it as dangerous, and denouncing those who advocate it. This is morally wrong. I think one of the regulars here has a sig line that says _"Wise men learn from the mistakes of others."_ or something like that. How can one learn from mistakes which are hidden and kept secret. Secrecy means that more people will re-invent this wheel by trial and error; and in this case there are consequences for errors.

There are those individuals who will always find a way to hurt themselves, there is nothing you can do to stop them. It is not your responsibility to stop people from doing things that might be dangerous. It _is_ your responsibility to properly warn people of the dangers.

Ethics are not always easy or clear-cut, and it is unfortunate that one's financial incentives are not always in alignment with the more socially responsible choice. Here is a commonly cited case study of (a lapse of) professional ethics (engineering ethics) which might help support my own thoughts on the matter: http://ethics.tamu.edu/ethics/tvtower/tv3.htm

There are also many reasons to leave this thread up that do not involve helping people boil acid. Journalists or accident investigators may find it useful. Laypeople attempting some task may be completely unaware of the danger. There are too many possible scenarios to list here.

Here are my suggestions, some of which have already been said.

 Watermark the page with a "Danger" background.
 Vet the posts for correctness
 Let people post their warnings.
 Let people post their setups (also let people comment on them)
 Post images (maybe allow them to be hidden) most people don't need to see them more than once, and it becomes bothersome.
 Post precautions and strategies to mitigate the danger.
 What is the first aid that should be applied to the person involved in an accident? Post that information.
 Do not discourage those who persist from asking questions.

I'm glad to see this thread is still alive.

PS I may edit this post later when I have time to fix the formatting


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## butcher

I was a tower man, I was on a crew who put up those radio, television, cable, and telephone, towers all over the united states, as a young man, we normally stacked 500 foot towers but we worked on all of them, the tallest I worked on was 1,800 footer. I have seen several tower accidents, survived a few. And know of other friends who live through some very close calls, and some good friend's who did not.

Four of my co-workers and good friends died falling to their death on them. 

I fell 60 foot tied to a winch line and a 150 pound weight, with two FM radio antennas and a run of coax and other out rigging gear, (the 150 pound weight is to send the winch line back down), we had a sears strap (the strap with two clips, normally which clips to your belt and the strap goes around the tower legs while your working), well this strap to ride the line, we sit on the strap and clip it to the winch line, with the weight between our legs, the antenna’s and coax is also tied to this line. This was a spliced winch line I was riding up on, was rigged on the 500' tower with pulleys, the job was to hang the two FM antenna’s and coax on top of this 500 foot tower, and do some other repairs, on the way climbing back down, tying coax to the tower, the college kid (winch operator) who did the winch line splice from our winch line and to the line rigged on the tower, his splice came loose, I always wondered what good that college education done him he could not tie his own shoe's.

The 60-foot fall powdered both of my femurs (legs) broke my back and put many deep cuts into my hide, one cut my calf in half to bone, another deep cut across my shoulder. When I hit the rock hard ground, I bounced about four foot, stayed conscious, look over at the winch operator, who just sat there staring at me, he would not move, frozen, I started yelling and cussing at him, after what seemed like forever he finally came out of shock and ran over to me and asked what should he do, I told him he had a radio in the truck to call somebody, the ambulance was 90 mile away, it took them time to get there, and my body was swelling and getting stiffer, when they moved me, I thought that the pain would kill me, as I was wrapped in 1000' of 3/8'' aircraft cable that fell from tower on top of me and I had to be cut out of this cable before getting me on a back board and stretcher, to beat all the ambulance had a flat tire on the 90 mile trip back to the hospital, they drove about 20 mile's on just the rim bouncing (to get to the gas station for the attendant to change their tire, you would think they would know how to change a flat.), (heck if both my legs were not broke I would have showed them ambulance drivers how to change a tire so I wouldn’t have had to endure that bumpy ash ride.

When the kid running the winch, came and seen me in the hospital I asked him why he froze and just sat on the winch starring at me after I fell, and why he did not come to help, He said he knew I was dead, I said, I was yelling and cussing at you, couldn’t you hear me, and see me moving? He said he could hear and see me, but he knew I was dead. My guess is if he did not go into shock that I may have, I really do not know?

While in the hospital we also found out my wife was pregnant with my first daughter (good timing?), my baby is 33 years old now.

As far as the wet ashing or other dangerous proceedure goes I see both arguments, and really am not sure what is the best (but whatever the decision is. it should be what is best for the forum,all of its members, and those who will ever read what we write).


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## hfywc

nobody argue that this procedure is highly dangerous. but sam showed that this can be done in a safe manner. all we need is to create a super safe procedure that anyone can follow.

here's my two cents...
1. since home refiners don't have a titanium reactor, we can place the reactor inside a bigger glass container that will catch any spill in case of breakage. incidentally we can cover the reactor with another container small enough to fit inside the big container to contain the toxic gas being emitted. and this will be bubbled in a sodium carbonate solution.
2. let the acid cool down totally first before handling the solution.
3. make sure one has enough time to finish the process.
4. must have plenty of sodium carbonate at hand in case of spillage.
5. start in small quantities to gain experience.
6. face shield, long chemical resistant gloves, lab coat, etc.

looking forwad to seeing a finished forum approved procedure.


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## Oz

hfywc said:


> nobody argue that this procedure is highly dangerous. but sam showed that this can be done in a safe manner. all we need is to create a super safe procedure that anyone can follow.


That will never happen, it is an inherently dangerous procedure.



hfywc said:


> looking forwad to seeing a finished forum approved procedure.


Again it will not happen as there is no foolproof way to do this. One would be a fool to say otherwise.

Have I worked with hot concentrated sulfuric acid? Yes. 

I knew the dangers and took the appropriate precautions knowing the risks. The “knowing the risks” part is why I “personally” have not deleted this thread as others need to know these risks. 

Life is dangerous, you never get out of it alive. Everyone needs to decide for themselves what is an “acceptable” level of risk. In my opinion only, we need to be sure to explain the risks of procedures that are out there to those that may see them without the cautions we can explain here. That does not mean we are promoting or endorsing those procedures however. Frankly, reading all posts as I do, I would guess that less than 1% of our forum membership has the knowledge, and proper equipment to deal with this at an acceptable level of risk. Make no mistake, this can result in permanent disability or loss of life.


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## threekgtvr4

Hello everyone. This is my first post to this forum. I've been reading it for almost a week now (I have a bunch of electronic "crap" laying around) and read a lot.

I came across this thread while trying to figure out how to get the PM's out of the s"crap" and decided at once that I wouldn't be doing it. But I personally would rather see it stay on the forum as it tells that you really, REALLY shouldn't work with this process.

I think that it should also probably be a sticky. This would be for that someone that figures they might give it a try without truly knowing the consequences. They might get the same idea as sam and give it a whirl without fully knowing the consequences.

But I for one already knew that hot acid is bad. Even that cold acid is bad to "play" with. I'm still kind of apprehensive about trying any of the processes in this forum, just because of the acids involved. But I'm intelligent enough to know about ANY process, regardless of danger level, BEFORE I give it a shot. This way I don't have any questions. And any questions I have about any process should be answered BEFORE I even think about trying it.

Thanks to all the people that have shown how to do things, and how to do them properly. IF I ever give this a shot, at least I'll know the dangers, the steps and the safer ways to do the processes.


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## Beirdo

Just as a thought... Is there any possibility that this method could work (although MUCH slower) just by using concentrated sulfuric acid with no heating? Granted, it may take weeks rather than minutes/hours to process, but it sure would be safer by a large factor (although still potentially dangerous). Something like a very large beaker less than half-full of sulfuric acid with ICs in it, left under a fume hood, with periodic stirring (once a day or whatever) until the plastic has been consumed?

I for one am not thinking of ever using hot concentrated sulfuric acid. Way past my comfort level. Cold, I might waringly use it, but still, I'd be more comfortable with it a bit more dilute. Again, that would likely serve to further extend processing time, but if it's just sitting there working away while you are busy doing other things all that time, the delay may not be that big of an issue. After all, I made fruit wines that I couldn't even bottle for a year....


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## Geo

Beirdo said:



> Just as a thought... Is there any possibility that this method could work (although MUCH slower) just by using concentrated sulfuric acid with no heating? Granted, it may take weeks rather than minutes/hours to process, but it sure would be safer by a large factor (although still potentially dangerous). Something like a very large beaker less than half-full of sulfuric acid with ICs in it, left under a fume hood, with periodic stirring (once a day or whatever) until the plastic has been consumed?
> 
> I for one am not thinking of ever using hot concentrated sulfuric acid. Way past my comfort level. Cold, I might waringly use it, but still, I'd be more comfortable with it a bit more dilute. Again, that would likely serve to further extend processing time, but if it's just sitting there working away while you are busy doing other things all that time, the delay may not be that big of an issue. After all, I made fruit wines that I couldn't even bottle for a year....



interesting question. i know concentrated sulfuric reacts to organics even when cool, just very slowly. the problem would be to keep moisture away from the acid while its processing. heating serves two purposes, first it speeds up the process, and second it keeps the solution hot enough to ward off moisture. if you cap the process, will it build pressure. can you cover the beaker with plastic wrap without the wrap being effected.


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## kjt124

Just for the sake of those trying to stress the safety issue on this process, I didn't actually see anyone describe what happens to 'tissue' affected by hot sulfuric acid or SO3 gas. In addition I have some experience with environmental chemistry and waste disposal so I will comment on that topic as well.

If you are going to use this method (which from a pure chemist's perspective sounds brilliant) it would be worth knowing the effects on living tissue (or any hydrocarbon for that matter). Sulfuric acid attacks the water in sugars, fats, various other hydrocarbons, leaving behind the carbon - hence the wonderfully simple carbonaceous slurry left from the wet ashing of your chips. What this means is THERE IS NO SAVING YOUR FLESH FROM A MISHAP. In addition, as stated before, the SO3 gas evolved during the entire process finds the water in your lungs, eyes, nose, etc. and dissolves to reform new sulfuric acid which then goes to work further on the hydrocarbons in the tissues as before. It is a vicious cycle that only ends once all of the acid is consumed or neutralized. In the case of your lungs - there is no possibility of neutralization.

Unless you are a well trained chemist with appropriate apparatus and you are well versed in regularly checking and maintaining your equipment, this procedure is not for you. You would actually be better off throwing your chips in the trash rather than risking any possibility of catastrophe using this method. There are not enough safeguards to make this an off the shelf method for the layman.

On another note, for those who are capable of pulling this method off correctly and safely and in a controlled enough atmosphere to whether the risks, here is a perspective from the environmental side...

Legally, the waste should be collected and disposed of to a properly permitted waste disposal facility equipped to handle acids and organics - suggestions would be The Environmental Quality Corp. in Detroit, MI, or Stablex for you Canadians - don't bother trying to move stuff across the border when it come to hazardous waste - it is an arduous task. On site waste treatment does require a permit in every state and province.

Now with that out of the way, for the hobbyists that simply want to be gentle on their local WWT plant and don't want to dump something down their drain that will give anyone a reason to come looking around...

There are only a few things that you want to control that will allow you to sequester this type of material to the local sewer (SEPTIC SYSTEMS ARE DIFFERENT - please don't follow this if you are on septic - you will kill all of your bugs and have a mess).

The first part if the carbonaceous slurry. This contains carbon (harmless), unreacted acid (corrosive), myriad other organic and nitrogenous compounds from the epoxies (usually harmless). If the only thing you wet ashed was the chips from boards and all you used is hot Sulfuric Acid, checking that the pH of the slurry is between 5 and 9 and adjusting accordingly with bicarbonate of soda accordingly is all that needs to be done to flush the slurry down the drain and rest easy with your plumbing and the local treatment plant. Additionally, the scrubber solution from your vapor recovery cell should only contain a weaker form of sulfuric acid from the action of the SO3 vapor on the water. pH neutralization on this will sufficiently reduce hazards to dump down the drain as well.

If you use other acids, oxidizers, flammables, etc. you may not simply assume that pH adjustment is an acceptable nor comprehensive treatment for hazard reduction.

I am sure most of us on this forum know this stuff, but again, I saw many people alluding to this information, but no one actually listing any of it. I hope this helps!


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## Geo

kjt124, thank you for pointing out the safety issues with this. the dangers of working with concentrated sulfuric acid has been discussed and pictures posted of examples of what could happen. alas, it was on another thread that was being posted on around the time this post started. perhaps one of the members that posted the pictures on Sam's post can put them here as well.kjt124, safety is stressed on the forum every time a process is recommended that has the potential to do serious harm.we certainly can use more members to help remind others that one slip or mistake can cause a life changing event.


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## kjt124

That is actually one of the main reasons I enjoy this forum. Huge volumes of valuable information is shared freely, but certainly not irresponsibly. My hats off to all of you. I feel honored to be a part of the community and will chime in any time I have information of use.


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## nickvc

The one thing most members of the forum never tire of reading is safety advice and ways to handle and to dispose of spent chemicals responsibly, anyone who posts such information is to be commended especially if they have expertise in the field, well done kjt124 8)


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## Richard NL

samuel-a said:


> A bucket of sodium bicarbonate is recommended to have around, just in case.



Miss Calm Morrison Hoke wrote:
"Extensive tests indicated that the use of water, either in a large tank or from a running tap, was considerably better in treating acid burns than neutralization."
Page 321 in Refining Precious Metal Wastes
http://www.scribd.com/doc/2815953/Refin ... s-C-M-Hoke page 328.
Cut you be so nice to edited the first post one more time ?.
And include : Lots of (warm) water if possible either in a large tank or from a running tap nearby, on a safe distance from the reaction, just in case.

And the use of a chemical resistant apron, can come in handy.

Please correct me if I'm wrong or made a mistake,i am still learning.


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## MicheleM

Good morning/afternoon/ evening

I know that is a very old thread, but I noticed that nobody answered to GEO question (I am commenting right now for future readers and to discourage the hot wet ashing process because some absurd YouTube videos...) :
yes, for, glob tops (cob), N/S bridge and very thin IC chips you can do "cold" wet ashing without dangers
(Always wear googles, gloves and mask to open and pour H2SO4 in a glass that you can seal)
Leave the glass outside and be patient ( weeks). I want to thanks who commented here so I avoided any idea to boil the acid;
Even if I could do with the proper safety measures.
Thanks,
Regards,

M.


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## patnor1011

Incineration is much faster and in many cases, it can be cheaper than the acid method. While I never tried what you call cold ashing I do not think it will work. It is called ashing because acid pretty much burns all resin when concentrated and warm. If you leave it outside it becomes diluted and may not dissolve all of the material.


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## MicheleM

Good morning/afternoon/evening

Dear Patnor1011
thank for your reply, i have some comments about what you said:


"
Incineration is much faster and in many cases, it can be cheaper than the acid method.
"
my response:
yes sure, but i was not comparing these methods, i was only responding to a precise question: "Could concentrated sulphuric/sulfuric acid wet ash an IC chip at lower temperatures?". 

"While I never tried what you call cold ashing I do not think it will work. It is called ashing because acid pretty much burns all resin when concentrated and warm. "

my response:
i called "cold" wet ashing , but it's simply room-temperature wet ashing. 
theoretically the concept of temperature can be very complicated, (see for example https://arxiv.org/abs/1711.03770) in the present case the typical temperature scale involved in the process (from 290K( 17 Celsius. 63 Fahrenheit) to more or less 523 K (250 Celsius, 482 Fahrenheit ) governs the kinetic of the reaction , only marginally (but with my surprise the literature is not very good) phase-change (https://pubs.acs.org/doi/pdf/10.1021/ja01878a030 ; https://pubs.acs.org/doi/10.1021/je00059a022) or ionizations processes. Because you have concentrated (over 95 pct) acid. the dynamics is governed by a power law that depends from temperature. this simply means that, if the process works a temperatures in a specific phase, it works at almost any temperature in that phase. and (hotter = faster) with a power law. 
Another important fact also depending by the temperature is the diffusion process, that improve the overall efficiency of the reaction.

experimentally: i tried successfully with Glob top embedded IC, N/S bridge IC and a single random chosen 5 mm^2 flat-packs.

"
If you leave it outside it becomes diluted and may not dissolve all of the material.
"
Yes, you have to close your system with a lid to avoid the H20 in the gas phase to enter. There are different ways equally safe to met this requirement, i prefer anyway to calculate the possible gas mole that could be emitted by the reactions , however it is sufficient to have enough space and use a resistant vessel/object, or if you prefer the gas to escape in any case, a plastic lid.


Regards,
M.


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