AR Reocovery Process Authentication Needed

[chrisv]

HI All, I'm very new to this forum and line of interest.
For the past 4weeks now, I have been researching, learning and in the past week, putting this method to trial. I am processing cell phones, I cut off all the gold plate and put it in one container, once that is all stripped, I put the blow torch to the circuit board for a minute and scrape off all the chips, etc to be left with a nice clean circuit board. I then cut off all the gold plate with a pair of pliars and put that in another container. Now I try and process the gold plated metals seperately to the gold plated circuit boards. Now the chemical process I've been trying out is as follows.
1oz gold plate/curcuit board, soak in 40ml Nitric Acid(tech grade) for and hour,
Then filter out the acid, mix a AR solution ( 30ml Nitric Acid & 120ml Hydrochloric Acid 36%) and pour it in with the gold plate. Leave it over night.
Then I filter the acid, which leaves me with a clear green acid, add 1pound Urea dialuted in 950ml boiling water, I add the Urea solution to the acid untill there is no more reaction, then I add 30g Sodium Metabisulphite dialuted with 950ml boiling water to precipitate the gold...

1) what do you think about this process?

I have tried it twice now, 1st time round, I forgot to filter the solution b4 adding the Urea and then the Sodium M and landed up with a greyish powder after rinsing and drying it which doesn't seem to melt at all.

I tried it again last night, but b4 I added the Urea and Sodium, I halfed the acid with the disolved gold, carried on with this whole process with one half of the solution and with the other half, I have been told to try and boil the Nitric Acid out instead of adding Urea and then just adding some Sodium M dialuted in some water and leave over night..
I also mentioned above, that b4 I put in the AR, I filter out the Nitric acid. I did this so I can try and recover the silver that would of got desolved.

 

[glorycloud]

You may want to read up again on the formulas for processing.
If you only have 1 ounce of cell phone boards, I would be surprised if you even had a gram of gold. I see you added a pound of urea and then
30 grams of SMB????? Where on earth did you get those amounts?

 

[lazersteve]

The green color of your AR solution suggests you are not driving your nitric reaction to completion.

Your initial nitric treatment should be performed on a hotplate at near boiling temperatures. You need to dilute your nitric acid with distilled water to 35% concentration.

Don't mix you nitric and HCl outright when using AR. Instead start with equal volumes of HCl and water ( 120 mL of HCl per ounce of gold ) and add the nitric to the heated HCl and gold in small increments until you either dissolve all of the gold.

Follow the above advices and you will no longer see the copper I chlorides (gray powder) and you can save the money you are spending on urea.

Steve

 

[chrisv]

You may want to read up again on the formulas for processing.
If you only have 1 ounce of cell phone boards, I would be surprised if you even had a gram of gold. I see you added a pound of urea and then
30 grams of SMB????? Where on earth did you get those amounts?

I got that formula from Ehow.com and there was a post which was very much the same that was written by some jeweller. I've been trying to find a formula that matches to somebody elses formula, I have noticed that out of every say 20 differant formulas/processes used, not one will be the same. I think the one from Ehow was copied from the jewellers as his one went into more detail as to reactions, etc and the one from Ehow was a bit more simplified.

 

[philddreamer]

Thanks Steve, I'm going to do just that on my next AR batch, first the HCL/water & then the nitric in increments. That should cut down on time spent in trying to evaporate the nitric, excess nitric comsumption... I like it!

Phil

 

[chrisv]

The green color of your AR solution suggests you are not driving your nitric reaction to completion.

Your initial nitric treatment should be performed on a hotplate at near boiling temperatures. You need to dilute your nitric acid with distilled water to 35% concentration.

Don't mix you nitric and HCl outright when using AR. Instead start with equal volumes of HCl and water ( 120 mL of HCl per ounce of gold ) and add the nitric to the heated HCl and gold in small increments until you either dissolve all of the gold.

Follow the above advices and you will no longer see the copper I chlorides (gray powder) and you can save the money you are spending on urea.

Steve

How long would you recomend that I do the initial treatment for?
And for the Second phase, shall I still filter out the nitric that contains contains silver? Then add new nitric to the heated up HCL and gold?
And Finaly, shall I not use the Urea anymore?
Thanks you guys for your help and advice, now the missus wont grind me for spending cash on things that iterrest me and not her

 

[lazersteve]

How long would you recomend that I do the initial treatment for?

Until the base metals are all dissolved and the gold/foils float freely around the beaker.

And for the Second phase, shall I still filter out the nitric that contains contains silver?

Yes.

Then add new nitric to the heated up HCL and gold?

After thoroughly washing the powder/foils.

Steve

 

[chrisv]

How long would you recomend that I do the initial treatment for?

Until the base metals are all dissolved and the gold/foils float freely around the beaker.

And for the Second phase, shall I still filter out the nitric that contains contains silver?

Yes.

Then add new nitric to the heated up HCL and gold?

After thoroughly washing the powder/foils.

Steve

Thanks a MILLION Steve,
I'll give this a trial tonight again, hopefully I'll crack it this time round.
Once the Nitric acid is added to the HCL solution with foils/powder, do I just heat/boil untill all the foils are disolved and the fumes produced turn white to indicate the Nitric has be boild out? And Finaly, how would I precipicate the gold with the Sodium M? I was thinking of weighing the foils and powder so I know more or less how much Sodium M to use.
I already cant wait to try this formula out tonight

 

[lazersteve]

Watch the fizzing bubbles coming off of the gold, as the bubbles decrease the nitric is be used up and the brown fumes will be gone. Before the last addition of nitric add a little extra HCl to see if the tiny bubbles begin again, if they do, you may not need any more nitric. This process is my version of GSP's original suggestion and practices.

Repeat the above process until the last of the gold is just barely dissolved and the tiny bubbles stop. In the beginning you'll have a fair amount of brown fumes (NOx) and lots of foaming/fizzing. As the nitric is used up the brown gas is no longer seen and a stream of tiny bubbles can be seen streaming off of the gold. When the fizzing stops, add a touch more nitric.

SMB is the easy part. After filtering the cold solution 100% clear add dry SMB powder 1-2 grams at a time while stirring (no more than 2 grams per estimated gram of gold in solution). You'll see some brown/purple foam possibly and more fizzing. Stir until the SMB dissolves. If stirring doesn't dissolve the solid SMB add a small amount of water, just enough to dissolve the powder. Once you see the solution turn brown do not add any more SMB until the brown settles a little and you can see the color of the solution. If the solution is not clear to faintly pale green add more SMB up to the estimated maximum. When you add SMB and the foam turns white you have likely precipitated all of the gold.

After adding SMB let the gold settle to the bottom of the beaker. Pure gold will settle very fast. Siphon off the liquid and rinse the powder twice with water and swirling to rinse the SMB out of the brown powder. Put this siphoned liquid in another beaker and heat gently until it is warm to drive off the excess SMB, any particles of gold suspended in the solution should settle to the bottom. Siphon and rinse any additional gold powder into the first beaker with the bulk of the gold powder. Test the spent solution with stannous chloride for residual gold or PGMs.

Wash the gold as per the standard process defined by Harold and summarized by me in other posts.

Steve

 

[chrisv]

Watch the fizzing bubbles coming off of the gold, as the bubbles decrease the nitric is be used up and the brown fumes will be gone. Before the last addition of nitric add a little extra HCl to see if the tiny bubbles begin again, if they do, you may not need any more nitric. This process is my version of GSP's original suggestion and practices.

Repeat the above process until the last of the gold is just barely dissolved and the tiny bubbles stop. In the beginning you'll have a fair amount of brown fumes (NOx) and lots of foaming/fizzing. As the nitric is used up the brown gas is no longer seen and a stream of tiny bubbles can be seen streaming off of the gold. When the fizzing stops, add a touch more nitric.

SMB is the easy part. After filtering the cold solution 100% clear add dry SMB powder 1-2 grams at a time while stirring (no more than 2 grams per estimated gram of gold in solution). You'll see some brown/purple foam possibly and more fizzing. Stir until the SMB dissolves. If stirring doesn't dissolve the solid SMB add a small amount of water, just enough to dissolve the powder. Once you see the solution turn brown do not add any more SMB until the brown settles a little and you can see the color of the solution. If the solution is not clear to faintly pale green add more SMB up to the estimated maximum. When you add SMB and the foam turns white you have likely precipitated all of the gold.

After adding SMB let the gold settle to the bottom of the beaker. Pure gold will settle very fast. Siphon off the liquid and rinse the powder twice with water and swirling to rinse the SMB out of the brown powder. Put this siphoned liquid in another beaker and heat gently until it is warm to drive off the excess SMB, any particles of gold suspended in the solution should settle to the bottom. Siphon and rinse any additional gold powder into the first beaker with the bulk of the gold powder. Test the spent solution with stannous chloride for residual gold or PGMs.

Wash the gold as per the standard process defined by Harold and summarized by me in other posts.

Steve

Hi Steve,
I just busy trying this new method out that you've recommended, but just one last thing, Im just about finished on the 1st stage, I've made a water and nitric solution, brought it just b4 boiling point, stripped most of the gold plating off the circuit boards, but some of it is still attached, do I just filter out the nitric, clean the flakes/powder and boards with plating on and chuck the load in the next stage of MCL, water and Nitric??

 

[lazersteve]

Please slow down and read my first response carefully again. Rushing things will only lead to more work in the long run.

Each stage must be run to completion before moving to the next step. Some steps require more time than others. Dissolving base metals is one of the longer steps. Sounds like you need a little more nitric and water with heating.

Steve

 

[chrisv]

Please slow down and read my first response carefully again. Rushing things will only lead to more work in the long run.

Each stage must be run to completion before moving to the next step. Some steps require more time than others. Dissolving base metals is one of the longer steps. Sounds like you need a little more nitric and water with heating.

Steve

Hi Steve,
I gatherred that after asking the question. I ran the 1st stage about three times last night untill most of the gold had lifted of the circuit boards and all the base metals were gone. I'll carry on from where I left off later on during the day. It is really looking better this time round than previous try's. Thanks again Steve

 

[chrisv]

Please slow down and read my first response carefully again. Rushing things will only lead to more work in the long run.

Each stage must be run to completion before moving to the next step. Some steps require more time than others. Dissolving base metals is one of the longer steps. Sounds like you need a little more nitric and water with heating.

Steve

Hi Steve,
I gatherred that after asking the question. I ran the 1st stage about three times last night untill most of the gold had lifted of the circuit boards and all the base metals were gone. I'll carry on from where I left off later on during the day. It is really looking better this time round than previous try's. Thanks again Steve

Hi Steve,
Me again, Im sure you getting fed up of me asking you question after question. I'm going to procceed with the second phase tonight but I just need one more question aswerred please. After a couple of 1st phase treatments, the gold has come off, the base metals have disolved, I've filtered it a couple off times but along with the dust and gold flakes are some green foils from the circuit board, I have removed most of them with a pair of tweezers but there is still traces of them, do I need to completely remove b4 going onto the second phase or will the second phase dislove them?

 

[nickvc]

The green foils shouldn't be a problem if they are non metallic as when your gold dissolves and you filter your solution they will be caught on your filter paper again.