# a lot of this stuff!!



## joheleh (Oct 30, 2013)

hi guys, recently a friend of mine gave me a lot of those pcb's (10-15kg)...they're all depopulated, just plastic base and...i don't know, is that gold? may i test them with nitric acid (70%) to see if it's all gold?
My idea was to treat them with HCl(33%) and peroxide(6%)
what do you think about all this stuff?


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## goldsilverpro (Oct 30, 2013)

Looks like gold to me. Probably runs between ten cents and forty cents per square inch of gold plated area.


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## samuel-a (Oct 31, 2013)

Very nice joheleh,

AP is certainly the way to go with those blanks.
Since there's no components, you'll have to find a way to keep them separated for the acid to work all over the surface.


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## joheleh (Oct 31, 2013)

3 more pics 


samuel-a said:


> Very nice joheleh,
> 
> AP is certainly the way to go with those blanks.
> Since there's no components, you'll have to find a way to keep them separated for the acid to work all over the surface.


thanks!! I hope to find a way to keep them separated, but it's a real problem. i have no ideas :roll:


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## patnor1011 (Oct 31, 2013)

Get some plastic forks from take away restaurants. Fit about 3 boards in each, you can break handle away.


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## joheleh (Oct 31, 2013)

patnor1011 said:


> Get some plastic forks from take away restaurants. Fit about 3 boards in each, you can break handle away.


Nice! I'll try that. I was thinking about the ratio of HCl and peroxide (6%) .... 1:1 seem good to me.


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## artart47 (Oct 31, 2013)

Hi !
I've stacked it up in a pile on the table with mixed-drink straws between each. then I'd pick up the entire stack, sqeeze it together and pack them into the inner bucket, ( the one with the drain holes like in Lazersteve's acid peroxide video)
If there is not enough to fill the whole bucket, pouring glass marbles in the voids will keep everything packed together. I washed the marbles with HCl because I diden't know if they were clean .
Hope it helps! Good luck! artart47


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## joheleh (Oct 31, 2013)

artart47 said:


> Hi !
> I've stacked it up in a pile on the table with mixed-drink straws between each. then I'd pick up the entire stack, sqeeze it together and pack them into the inner bucket, ( the one with the drain holes like in Lazersteve's acid peroxide video)
> If there is not enough to fill the whole bucket, pouring glass marbles in the voids will keep everything packed together. I washed the marbles with HCl because I diden't know if they were clean .
> Hope it helps! Good luck! artart47


Thank you so much, this method seems very efficent, i'll try it soon. What ratio of AP have u used? 1:1? 1:2? (i've got HCl 33% and peroxide 3,6% 12vol)


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## goldenchild (Oct 31, 2013)

You run any of these in hot sodium hydroxide? There may be more gold in the traces under the plastic.


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## joheleh (Oct 31, 2013)

goldenchild said:


> You run any of these in hot sodium hydroxide? There may be more gold in the traces under the plastic.


unfortunately i don't know how to do it properly, i'll work them just with AP...but, if someone can post me a link with some info's  it's a little difficult for me to understand perfectly the forum, my english is scolastic...now call me dumb XD


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## pattt (Oct 31, 2013)

Hi johele,

Just my thought (as a newby), AP is the way to go, Hot sodium hydroxide ( caustic soda ) is very dangerous if not handled with very much care, one drop in the eye and you will be loosing that eye :!: 
Do a search for it here on the forum.
The gold you see will come off in AP, the gold under the "plastic' coating (if any) will stay on, and if you wish you can do that later, but like i said, be careful !
The peroxide normally used is 3%, if the % is to high it could dissolve the gold.
I'am sure someone will get you more info.

also, study much more , after reading some of your posts, I am sure you need more reading :!: 
btw: nice boards.(good starting material)

Have fun and stay safe.

Pat


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## chlaurite (Oct 31, 2013)

Wow, really beautiful! :mrgreen: 

Where do people _get_ things like that? I mean, I used to work at a company that made their own boards, and although we had tons of waste/scrap around (_wow_ but I wish I knew then what I know now!), I never saw anything even remotely like _that_ disposed of. Most of the waste I saw came from proto boards or, when actually from the manufacturing floor, bad runs through the wave soldering machine (aka "completely covered in solder). Certainly not never-used blanks like you have here.


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## joheleh (Oct 31, 2013)

pattt said:


> Hi johele,
> 
> Just my thought (as a newby), AP is the way to go, Hot sodium hydroxide ( caustic soda ) is very dangerous if not handled with very much care, one drop in the eye and you will be loosing that eye :!:
> Do a search for it here on the forum.
> ...



you're right Pat, i preferred to try my refining experiments with this batch now, because i'm not expert as you in this wonderful forum, i've to learn and to read a lot, AP method seems very user firendly to me, without annoying base metals like in plated pins, connectors etc etc.

i wish (again) to thank you all for your answers, your expertise and knowledge. 



chlaurite said:


> Wow, really beautiful! :mrgreen:
> 
> Where do people _get_ things like that? I mean, I used to work at a company that made their own boards, and although we had tons of waste/scrap around (_wow_ but I wish I knew then what I know now!), I never saw anything even remotely like _that_ disposed of. Most of the waste I saw came from proto boards or, when actually from the manufacturing floor, bad runs through the wave soldering machine (aka "completely covered in solder). Certainly not never-used blanks like you have here.



chlaurite, this friend of mine works for an import-export society, they're chinese. he gave me that stuff because it was out conformity...for me it's a good fortune i've got those blanks...i know i'm a noob with a "pro" batch...i don't wanna mess up everything


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## kkmonte (Oct 31, 2013)

You don't want to use a 1:1 ratio of HCl and 3% H2O2, that is way too much. Even a 2:1 is too much (iirc). I think Laser Steve's recommendation was 3:1 (3 parts HCl to 1 part 3% H2O2). You just need the oxidizer (H2O2 in this case) to get the reaction going, it will start turning green as it dissolves the copper. As Pat said, too much (or too strong) of an oxidizer and it could dissolve some gold. Once the AP reaction gets going, if you keep it clean you can use it over and over again. Just watch what metals you dissolve in it, if you can just dissolve copper it will last a long time (and slowly grow in volume). You want a nice lighter emerald green color. 

If it starts to get too dark green, you need a little more oxygen. If you can get an aquarium bubbler, run the tube and bubble air into the liquid. This will keep the reaction going (and also speed things up a little bit especially in cold weather).

If you start to see white powder forming, you need to add some HCl.

-Ken


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## everydayisalesson (Oct 31, 2013)

Hey jo, an idea came to mind. how about hair combs to keep them separate? You can get like a pack of 20 at the dollar store. Not sure if the plastic is ok, you'll have to ask the guys.

Mike


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## patnor1011 (Oct 31, 2013)

chlaurite said:


> Wow, really beautiful! :mrgreen:
> 
> Where do people _get_ things like that? I mean, I used to work at a company that made their own boards, and although we had tons of waste/scrap around (_wow_ but I wish I knew then what I know now!), I never saw anything even remotely like _that_ disposed of. Most of the waste I saw came from proto boards or, when actually from the manufacturing floor, bad runs through the wave soldering machine (aka "completely covered in solder). Certainly not never-used blanks like you have here.



Well, I got about bucket full of round boards from smoke detector. I presumed smoke detector is there to save life so there might be more gold on them. They sure looked very nice and promising. While I do not have numbers I remember that yield was so poor that I decided not to get more of that stuff. If I come by some free ones I will do them but I would not pay anything for them.


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## Anonymous (Oct 31, 2013)

Just a word of caution.

Don't get too excited just yet. I had a 500Kg batch of these in the UK that turned out to be pre engineering units. What I thought was plating was in fact a dusting!


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## goldenchild (Oct 31, 2013)

The sodium hydroxide isn't used in place of the AP process but rather to remove the masking of the traces on those boards. You would only have to process one of each type of board you have to confirm that you do or dont have gold under the masking. 

LaserSteve's site

http://www.goldrecovery.us/goldrecovery/videos/ShowVideo.aspx?id=soldermask&yt=0


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## Anonymous (Oct 31, 2013)

Scratching the boards with a screwdriver will tell you a lot faster than soaking them.


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## goldenchild (Oct 31, 2013)

spaceships said:


> Scratching the boards with a screwdriver will tell you a lot faster than soaking them.



True but what if there is gold in some areas and not others? Also, if the plating is very thin you might take that off revealing only the copper underneath. Either way the O.P. has to decide how to proceed.


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## Anonymous (Oct 31, 2013)

goldenchild said:


> spaceships said:
> 
> 
> > Scratching the boards with a screwdriver will tell you a lot faster than soaking them.
> ...




I agree he does, however there are only a few types of card here, and they are clear cards, and it's not hard to sample the contacts with a screwdriver if you can see colour differences.


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## joheleh (Nov 1, 2013)

i'll proceed with the straws method, i've this 34x40cm plastic box for a uniformed batch of pcb blanks


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## artart47 (Nov 3, 2013)

Hi !
You only need alittle H2O2 to get the reaction going. it will begin oxidizing the copper so that it can form copper chloride. The copper chloride in the solution does the leaching. once the reaction is going you supply oxygen by putting an aquaium air pump line that bubbles air into the solution and there is no need for additional H2O2.
If you have high percentage of H2O2, it will cause some of the gold to disolve. As you continue to reuse the solution it will become saturated with copper and any gold will cement out as a black powder in the bottom of the bucket.
artart47


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## joheleh (Nov 3, 2013)

artart47 said:


> Hi !
> You only need alittle H2O2 to get the reaction going. it will begin oxidizing the copper so that it can form copper chloride. The copper chloride in the solution does the leaching. once the reaction is going you supply oxygen by putting an aquaium air pump line that bubbles air into the solution and there is no need for additional H2O2.
> If you have high percentage of H2O2, it will cause some of the gold to disolve. As you continue to reuse the solution it will become saturated with copper and any gold will cement out as a black powder in the bottom of the bucket.
> artart47


Ok. So i'll use 3000ml of hcl and 750ml of peroxide at 3,6%


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## Pantherlikher (Nov 3, 2013)

Hi...
You can use the 3000Ml and just a splash of Peroxide...but it will take longer to get the reaction going. The drawback from using more is some gold will dissolve and eventually come out of solution as black/brown powder.

Peroxide is the oxidiser so adding any will dissolve anything, almost.
I have a small 1gal. bucket. I save alittle, maybe 1ml, of AP and add it to more HCL when I have stuff to process. That way I don't need Peroxide. Then again, time is my friend so it sits for a week or more.

B.S.


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## joheleh (Nov 3, 2013)

Pantherlikher said:


> Hi...
> You can use the 3000Ml and just A SPLASH of Peroxide...but it will take longer to get the reaction going. The drawback from using more is some gold will dissolve and eventually come out of solution as black/brown powder.
> 
> B.S.


...a splash? how much in 3000Ml ?


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## Pantherlikher (Nov 3, 2013)

I guess the technical term would be...based on how impatient you become...
Start with 1ml and let rest for a week. Aggitaing when aggitated.
If impatient, add as many ml as you feel neccessary to get the job done in a minute.

Somewhere in between there is good. You only need enough oxidiser to get the copper to work. It becomes a continueous process once kick started. 

Just remember, the more you add, the more gold will also dissolve and eventually be dropped.

There is a ton of posts on specific amounts of each but I've found you only need a tiny amount, 1ml or less to get it going. Add air and let nature take it's course.

Other then adding way too much...50/50... you can't add too little peroxide. Just a longer process time.

B.S.


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## joheleh (Nov 4, 2013)

thanks, your help is very appreciated, one LAST thing, hvae u ever seen this video (this is the reason of my question about ratio in AP)...he uses 1:1, just bad knowledge of the argument?
http://www.youtube.com/watch?v=rM87TEZXCfg


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## pattt (Nov 4, 2013)

Johele,

read more on this forum ,watch less youtube :!:,or just the youtube vids from our senior members 
or lazersteve's website ( http://goldrecovery.us/forum_search.asp ) and others.

The answers are also already given here in your post,

no need for that amount of peroxide :!: 
for foils you don't need aqua regia, you can use hcl/bleach, so no nitric needed,
if you want to do it in AR, the use of urea is not advised here either :!: 

Pat

edit: to add website


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## joheleh (Nov 5, 2013)

Believe it or not i've found the solution, for me is easiest and cleaner to use nitric acid solution in 50/50 with distilled water, i've ran some test, very fast and clean.


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## bigjohn (Nov 5, 2013)

joheleh said:


> Believe it or not i've found the solution, for me is easiest and cleaner to use nitric acid solution in 50/50 with distilled water, i've ran some test, very fast and clean.




I hope you get your nitric cheap. Chemical cost could Eat your profit on those.


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## joheleh (Nov 5, 2013)

7$\Lt


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## bigjohn (Nov 5, 2013)

Thats not bad at all. I pay $9 a pint plus hazmat shipping. My nitric is as valuable as my gold. :lol:


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## joheleh (Nov 16, 2013)

here i'am with a little update, i've collected all the gold leaves with nitric solution (10Kg of pcb's with 4Lt Nitric acid/distilled water 1:1) and i've putted them in AR...now i'll drop the gold with SMB and wash properly the powder as seen in gold'n'scrap site ( water, ammonia and Clhoridric)


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## joheleh (Nov 18, 2013)

my precipitation....as u see stannous chloride test gave me orange color...i'll wash the powder with boiling HCl, water baths, and ammonia
http://www.youtube.com/watch?v=4CG_oLN2T0E


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## goldenchild (Nov 20, 2013)

Just one thing about your video. One of the functions of the ice is to ppt any silver chloride that may be in solution. So after adding the ice and stirring you should filter your solution once more to remove any silver chloride. You should also let your gold settle more before testing. Overall looks good though.


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## Harold_V (Nov 21, 2013)

goldenchild said:


> You should also let your gold settle more before testing.


I disagree. If gold chloride solutions have been properly evaporated, precipitation is virtually instantaneous. You can see that clearly if you use ferrous sulfate, already dissolved in water. It's a little different when you use SO2 gas, as you must introduce the gas continually, until all the gold is down. Therefore, you must test regularly, while precipitating. 

Generally, the only reason not all of the gold comes down is a lack of enough precipitant, and time won't change that. Testing should come on the heels of having introduced the precipitant, so you'll know if the solution needs more attention. I also suggest that the gold that comes down should be stirred, to liberate any trapped gold chloride that may have been dragged down. That, of course, applies only to a heavy concentration of gold. Very dilute solutions are highly unlikely to suffer that fate.

Harold


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## moose7802 (Dec 14, 2013)

$7 a liter for nitric sounds pretty expensive to me! I pay $7 a gallon and still would not run these boards in a 50/50 nitric bath. AP is definitely the way to go, it's called patients which is a virtue. 

Tyler


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