What did I do wrong?

[matafy]

I've been curious for a very long time now and this is my first time ever trying this. I'm not much into the gold business, but I have always been wanting to experiment with this process...

The method I used was as follows:
1) 5 Pentium processors (in coffee pot)
2) Muriatic Acid 14% / Swinning pool Chorine 10%
Poured HCL enough to cover 1/8 inch over the top
Slowly poured about 1/4 cup of CL
waited for about 15 min to dissolve
3) filtered solution with 3 coffee filters
the solution was bright yellow
4) heated to a low simmer for an hour to kill any
chlorine left over
5) Let it sit for 24 hours just in case
6) Stirred slowly and poured SMB (Stump-Out)
it turned the solution dark brown, but no
precipitation...

7) Need help with what I did wrong.

 

[NobleMetalWorks]

1. Was the coffee pot clean?

2. You're HCl is a diluted solution, you might want to warm it until it evaporates some of the liquid so that you have a more concentrated HCl. But do NOT boil it, just hot enough to start the evolution of steam. I use poor man's AR to process CPU's, I have not tried the HCl / Cl method on CPU's. I am comfortable using AR to process CPU's and have stuck with it since. But it takes longer than 15 minutes for a HCl / Cl solution to dissolve gold. Did you test with Stannous Chloride for gold content? You should be proving gold content before you filter.

3. LaserSteve has a video and instructions on what you are attempting, you might want to watch them. I believe you should add water, if you evaporated off some, you might not have enough to react properly with the stump out.

4. I believe you should add water, if you evaporated off some, you might not have enough to react properly with the stump out. Did you decant into ice? Stump out will not work good in hot solution.

You can search the forum, the correct way of doing this is posted all over the forum, also there are YouTube video's.

Hope this helps a little...

 

[Geo]

any gold that was dissolved cemented back out as fast as it it dissolved. did you test this yellow liquid with stannous chloride to see if it had gold in it?

 

[lazersteve]

What does the MSDS of your brand of Stump Out list as the ingredients?

The brand of stump out that contains potassium metabisulfite is Bonide. Several other brands of stump out use nitrates as the active ingredient.

Steve

 

[matafy]

Sorry for responding late. I've been very busy researching this process a bit more. So, my equipment is clean. I used stannous chloride and revealed positive for Au and I'm using stump out by bonide. The active ingredient is sodium metabisulfite, not potassium metabisulfite. Could this be the issue (sodium vs. potassium)?

 

[butcher]

It most likely still contains some chlorine. the HCl percentage seemed a bit low and the chlorine content a bit high, I would evaporate the solution down some, add a little HCl while still very hot, and then dilute and cool, and see if you have a brown powder in the morning.

 

[Palladium]

The active ingredient is sodium metabisulfite, not potassium metabisulfite. Could this be the issue (sodium vs. potassium)?

Both will work.
Potassium metabisulfite has a molar mass of 222.32 g/mole
Sodium metabisulfite is 190.1 g/mole

So you'll need to use about 17% more (by weight) of the potassium salt to deliver the same effective SO2 as the sodium salt.

 

[Westerngs]

Is there enough gold to precipitate out? I don't know how much gold is contained in 5 pentium processors, but if it is very little, the gold might be so little that it may be in a fine particles suspended in solution. If so, in a day or two they would settle to the bottom of the vessel, but you might have a hard time collecting it.

 

[unitedgl]

So what iam seeing here is that HCL/CL can be used in one step to remove gold from CPU’S directly into solution therefore skipping a AP process?

Also “potassium metabisulfite” can be used instead of “sodium metabisulfite” to drop the gold from solution?

 

[lazersteve]

In my orignal response above I missed the part about the use of HCl-Cl directly on the Pentium Pro processors. I feel you may not have allowed everything to dissolve based upon the times you referenced in your post and the use of HCl-Cl directly on non-foils.

Are there any metallic solids left in the original reaction vessel? If yes then you did not complete the dissolution and have more work to do.

I suggest hot dilute nitric acid (35%) until on any gold top ceramic cpus until all of the repective pieces fall apart (top plate, bottom cover, gold foils lift, dies fall loose, and legs fall off). Once this stage is reached filter out the blue solution and add HCl to recover the silver as a chloride.

The solids (all parts and foils) are then placed in a clean beaker and cover with twice their volume of HCl (30%+). Now place this vessel on the burner with low-medium heat and a watch glass. Add 1 mL 70% HNO3 per pentium pro cpu processed. Let this react until no further action is observed.

If you still see metallic solids (pins and foils only) add another dose of nitric as above. Repeat until all metallic solids are dissolved and there remains no visible gold on the dies or ceramic housings.

Ice and filter the cool solution until 100% transparent. Add 1 gram of SMB to transparent solution per pentium pro cpu processed.

Test the left over solution with stannous chloride. If positive add enough SMB to remove the positive result. Add in small increments allowing to settle and testing between additions. Beware of brown flase positives.

Process the brown powder by traditional washing, drying, and melting techinques.

Steve

P.S.: I will upload photos later.