ewaste gold recovery for science fair project

[mechsupply]

Hello
I am a IT reseller so I tend to accumalate a lot of ewaste as a byproduct of that we normaly just sell it off to bulk buyers but I have a son who is interested in doing some chemical gold recovery for his science fair project. He is the one who generally does the tear down on the machines when we get a few shelves full and has always been interested in process. I would like to keep it safe and simple and actual yields are not anything we would worry about. ( he would love if he could get a little BB of gold though)
Currently he has saved about two pounds of pins from some telecom and networking backplanes, 2 pounds of cpu's and about 1 pound of gold finger trims. I am not sure what would be the easiest for him to do or if the process would be the same for all three and that is why I am here. I know there are a ton of tutorials on the web but I wanted to ask you experts on what would be the best (safe and educational) way for what we are trying to do.
Thanks in advance for any and all advise.

 

[lazersteve]

The easiest and quickest route to a BB is using the small scale AP experiment I describe here:

Acquaintence With Acid Peroxide

and for more AP details

AP FAQ

Don't forget to check out the Guided Tour link below as well.


Steve

 

[kkmonte]

Or better yet, click on LaserSteve's link in his signature to his store and buy his Recovering Gold using AP from fingers DVD. Best money you'll ever spend, each step is clearly demonstrated. You should also thoroughly read through the safety section (and so should your son) Safety should be the number one concern.

 

[mechsupply]

Steve
Thanks after a quick glance it looks like this is exactly what I wanted to find. Off the shelf chemicals and all.

 

[mechsupply]

Hello
I am going to get my materials for this as we are going to start this tonight and hopefully will have some results by sunday. Here is my list of what I think I am going to need
muriatic acid) from Lowes
3% Hydrogen peroxide
glass bowls glass jars plastic lids etc
funnels various sizes
plastic tweezers
rubber gloves
face mask
spray bottle
clorox bleach
hot plate??
strainer plastic
Does it look like I am forgetting anything? Anything pointers?
I am not sure if we are going to refine the foils we get and it really depends on how much more material we need to make his presentaion for the science fair. We may just explain that part of the process and display the foils in a glass jar. (kind of like the soveniers you see in the black hills or other gold areas)

 

[kkmonte]

Shouldn't need a hot plate to do AP, unless you are in a big hurry, and if you heat up AP too much, I think you could dissolve some gold.

One other thing you will need is some coffee filters to fit the strainer to dump your liquid through, while you are decanting (pouring off the top part of the liquid), you'll want to dump through a coffee filter in case some of the foils come out, but try your best to keep them in the bucket. Then once you have dissolved your gold (if you do), you'll want to run your auric chloride through a filter to get any non-gold out. (Make sure you wash all the yellow out of the filters with a spray bottle). Also when you do the first part, wash down all the gold foils that fell into the filter back in the bucket after you have gotten out 95% of the liquid.

 

[Lou]

Glad to see your son is doing science! I have been in and judged science fairs so if he needs any help, I'm happy to help.

I always thought a really good science fair project would be to optimize the conditions of a silver cell to give large crystals.

Best,

Lou

 

[mechsupply]

Coffee filters I have on hand.The hot plate was more of a after thought and I had hoped to find one at the thrift store but no luck. '

We have the fingers soaking and Joe (my son) is pretty impressed with reaction and how fast it started. He decided he wants to go ahead and refine them so now I have to order some sodium metabisulfite. Unless someone can point me to some type of local place that may stock it or is there a possible off the shelf substitute?

 

[Golddigger Greg]

Try any place that sells wine kits in your city, they should have it.

 

[mechsupply]

First thanks everyone for the tips and I have a great respect for what you guys do hear as we have been watching videos and reading the forum and there is a lot more to this then I ever expected. The shear mass of material covered on this forum is mind boggling.
We just started a batch of backplane pins as the plan is to be able to demonstrate the different phases and have samples of each ( HCl-Cl in liquid state) then one of the gold powder and then if everything goes right a gold bb button.
Our first batch seems to be going a lot faster then what I had anticipated and is wondering is that a sign of something bad? It has been less than 24 hours and the gold fingers seem to be 99.9% clean already and we had expected it to be tomorrow around noon.(From reading on the forum)

 

[lazersteve]

Small runs of fingers in AP strip very fast due to the high liquid to scrap ratio. The more scrap you put into smaller amounts of liquid will tend to saturate the solution faster and slow the process. When you work with a small scale reaction you have very little copper and plenty of room for agitation. Agitation of the AP liquid is one of the primary keys to getting the fingers to strip rapidly.

The more "elbow room " in the container, the faster the fingers strip. The small scale experiment I outline in the referenced thread typically is finished overnight or only slightly longer. Pulling the fingers and rinsing as they strip clean helps speed things along as well as the fingers don't shield each other from the solution.

Steve

 

[mechsupply]

Steve
Thanks. I just ordered your Acid Peroxide Refining Booklet and hope you do not mind if we use that as cite reference in his project.

 

[mechsupply]

OK so far we have been successful in the cleaning of the foils and dissolving them in the HCl-Cl and we just now are bringing it back with the smb mix. My next question and I apologize as I cannot find the next procedure so I am assuming that we filter out the powder after allowing it to settle. After that should I be rinsing the powder in plain water or ? and how many times do we need to rinse? Last is there anything else I need to do before we do the melt?
Thanks in advance for any and all advise.

 

[lazersteve]

Before you add SMB you need to be sure the solution is 100% transparent. You should be able to read the paper through the solution.

After the gold is precipitated and slowed to settle, pour off the clear liquid.

The washing process is found in the Guided Tour --Reaction list #8 the first item in this section.

Steve

 

[mechsupply]

Steve
The solution went clear within about 5 minutes and we even gave it about another 10 after that watching (again) your videos. I just did another order off your website for the tin as I forgot about the stannous chloride. To keep moving forward i will just keep the solution back and test when the tin comes in and just start cleaning the mud that we have already.

 

[mechsupply]

Gently pouring off didn't work well for us and I think it is because I used a round pyrex bowl that does not lend to pouring out of very well. I am going to have to try to figure out a siphon method or maybe steal the turkey baster.
Are the powders normally this fine? I guess I was expecting them to be more dense and stick together. I even tried filtering and the particles went right through.

 

[lazersteve]

Pouring works best with heavy gold that settles fast.

If your gold is so fine that it drifts up from the bottom with any motion of the container, siphoning may be best. You could also invest in some lab grade medium speed filter paper (eBay) and fold it so it fits in your funnel. Make sure to get the 'ash less' filter papers as they burn away clean and leave the gold behind. If your gold is dark brown or black it needs a second refining use a minimal amount of solvent on the second go around. Try to keep your gold solutions concentrated as this tend to precipitate better and settle with ease. If you can get light brown to blonde colored gold precipitated, pouring should be a breeze.

Steve

 

[Palladium]

Gently pouring off didn't work well for us and I think it is because I used a round pyrex bowl that does not lend to pouring out of very well.

A trick that one can use when pouring from a round container or from something without a lip or spout is to hold a glass stirring rod against the lip. The stirring rod will break the surface tension of the liquid and allow it to guide the liquid into the receiving vessel instead of pouring over the lip and running down the bowl.

 

[mechsupply]

I did a second round of refining and used siphoning (from Steve's video) I dried my powder and it has the color consistent of a light cocoa. I am assuming I am OK now. We ended up with 3.5 grams. We started with 14.5 oz of finger so is 3 grams close to normal or did we miss some?

On the second batch where I am using pins about 90% of them seem to be unaffected and still show all their gold. I am assuming a non copper base metal. What would be the next easiest to do? (CPU or ram)

 

[mechsupply]

Thanks for all the info you have been giving me on the forum for my sons science project. In my rush to get material for my second batch I tried to do a batch of pins and processors. Big mess! This turned my ap black but 90% of what I added did not strip at all. I have since rinsed it down and it just looks like a mess. I hate to waste this as it about 5 pounds of material and if anyone is interested let me know and I will mail it off. (most is heavy plated back plane pins plus about 2 pounds of mixed cpu's)