Palladium precipitation

[Rem123]

Hi. PC DDR RAMs they are like 1kg weight.

 

[Geo]

1kg of DDR will yield more than 1g of gold. The question would be, can you reclaim what's there or not. It depends on your level of experience.

 

[Rem123]

I do first dip the gold fingers in nitric acid for some days. After that I filter the golden foils and dissolve them in AR using minal amound of nitric acid. Later I precipitate with SMB and wash several times with water, and hydrochloric acid and collect the powder. But I am wondering should I precipitate with copperas first and then dissolving again with AR and then precipitating with SMB?

 

[Geo]

The gold on the fingers is only about 1/3 of the gold in ram sticks. The bulk of the gold is in the IC chips. That was my point. If you can't reclaim the gold from the chips, you will not recover 1g per kg.

 

[Rem123]

Yes I know there is gold in IC chips I collect them for another processing. But I have never processed them. I think I should burn them until they get into dust and then process the dust. And does every IC chip has gold in it or not because I opened some and I did not see gold bondings?

 

[Geo]

Assume all IC chips contains gold. The bond wires can be as small as 1 micron in length and is difficult to see a single bond wire, if at all, with the naked eye. It's only after they have been collected in numbers that you can see the gold.

 

[Rem123]

Ok thank you. But can you tell me how is the process about the IC chips?

 

[Geo]

Incinerate until the chips are white ashed. Mill to a fine dust. This will take more than one milling. Mill once and remove heat spreaders, leads and any large pieces that did not incinerate well. This is done by screening the material. I use 1/4 inch hardware cloth to remove really large pieces. Then I screen using window screen, this is where the copper and steel leads are removed. Anything that will not pass through the window screen is milled again. Then it is screen through #100 mesh sieve. Gravity separate the lighter ash from the metal fines using a small sluice. Collect the heavy fines and leach in nitric acid to remove the copper and silver. The only metal to remain will be gold. Dissolve in aqua regia and filter and drop.

 

[Rem123]

Okay thank you my fried. Another question is it better to precipitate gold first with copperas and redissolving and precipitating with smb or only copperas or only smb?

 

[kurtak]

Backing up a bit to the original question about precipitating & testing for Pd with DMG

Making the DMG testing solution

Dissolve 4 grams of NaOH in 100 ml of hot water then add 5.81 grams of DMG - the 4 grams of NaOH allows for ALL the DMG to dissolve thereby giving you a very effective test solution

Unless the (acidic) solution to be tested is VERY DILUTE the NaOH will have NO affect on the DMG test for Pd

Testing the solution; - put 1 ml solution in a test tube - add a couple drops of the test solution - if there is Pd in the solution being tested you "will" get the canary yellow precipitate of DMG Pd

if you get any other color precipitate it is because you used WAY to much NaOH to make your test solution (or you solution is VERY dilute) which is then likely adjusting the Ph up to a point of allowing other metals to precipitate as their hydroxides

In that case acidifying the (test) solution (to Ph 1) should dissolve all the hydroxides leaving behind only the yellow DMG Pd - if there is/was Pd in the solution to start with

if you don't get the yellow DMG Pd precipitate --- there is NO Pd in the soluton

Kurt

 

[Lino1406]

Good to hear from you Kurtak despite shortage of time

 

[Rem123]

Thank you Kurtak I will take your advice and try it. Thanks. If you can please answer my previous question for the gold precipitation.

 

[Geo]

Sorry, I'm not Kurt, but it's best to precipitate from a dirty, mixed metal solution using ferrous sulfate first. Rinse well in boiling water and redissolve. Filter and drop with SMB. This will get you in the high 90's on purity. I usually achieve 99.8% pure using this method.

 

[Rem123]

Oh yes thank you and dont be sorry the question was to the all in the forum not specificaly to Kurt. And can anybody tell me should the copperas be chemicaly pure which in white color or it can be comercial for plants which have greenish color. I have seen a sucessful experiments with the comercial one but which is better?

 

[Geo]

I generally make my own. A couple of ounces of rusty nails in a 1000ml beaker. Add 450ml of tap water. Carefully add 50ml of concentrated sulfuric acid on low heat until the nails dissolves or the reaction stops. Remove from heat and let it cool completely. Filter clear and use. If crystals form, add water until the crystals dissolves and filter and use.

 

[Rem123]

Ok thank you.

 

[spoke27]

Backing up a bit to the original question about precipitating & testing for Pd with DMG

Making the DMG testing solution

Dissolve 4 grams of NaOH in 100 ml of hot water then add 5.81 grams of DMG - the 4 grams of NaOH allows for ALL the DMG to dissolve thereby giving you a very effective test solution

Unless the (acidic) solution to be tested is VERY DILUTE the NaOH will have NO affect on the DMG test for Pd

Testing the solution; - put 1 ml solution in a test tube - add a couple drops of the test solution - if there is Pd in the solution being tested you "will" get the canary yellow precipitate of DMG Pd

if you get any other color precipitate it is because you used WAY to much NaOH to make your test solution (or you solution is VERY dilute) which is then likely adjusting the Ph up to a point of allowing other metals to precipitate as their hydroxides

In that case acidifying the (test) solution (to Ph 1) should dissolve all the hydroxides leaving behind only the yellow DMG Pd - if there is/was Pd in the solution to start with

if you don't get the yellow DMG Pd precipitate --- there is NO Pd in the soluton

Kurt

Dear Kurt Why Hot water ?

 

[Charles1975]

kurtak I thank u for good advice. Simple easy to understand and priceless Information.

 

[Zhazham]

I'm wondering, if it makes any sense to test with zink? I have greenish solution left of processing gold plated silver. Cemented silver, dropped gold already etc. Solution is very diluted. Added way too much SMB and i was then adding lot of water to get rid of SMB ice. Cold conditions, so i didn't get SMB to react with gold at first.

Now i have this solution and would like to know if it has any palladium or other PGM's. Don't have DMG or stannous at the moment. Solution is going in to stockpot anyway but i'm curious to make a small test with what i currently have, while waiting for better conditions.

 

[orvi]

I'm wondering, if it makes any sense to test with zink? I have greenish solution left of processing gold plated silver. Cemented silver, dropped gold already etc. Solution is very diluted. Added way too much SMB and i was then adding lot of water to get rid of SMB ice. Cold conditions, so i didn't get SMB to react with gold at first.

Now i have this solution and would like to know if it has any palladium or other PGM's. Don't have DMG or stannous at the moment. Solution is going in to stockpot anyway but i'm curious to make a small test with what i currently have, while waiting for better conditions.

Zinc will precipitate almost all metals in solution. If you cemented silver with copper metal before, all palladium dropped with silver.

Without proper testing, everything is just guessing. Distinguishing black precipitate of palladium from vast ammounts of copper... I will not rely on this approach.
Make stannous from tin and HCl, it´s easy and bulletproof.