Sub Zero

I have some AR from the Sub Zero Method. After 3 pounds of SMB in Hot water Added to this mix it still shows Gold in the Mix Black-Purple.
Any Ideas on how to clean up the last of it. The mix is 1/2 HC1 and 1 pound Sub Zero. I did about 30 pIII CPUs. Also so about 1.8l water was added. I wonder at putting more and more SMB in but if I need to I can.

Destroyer,

3# of SMB is a lot to add to a solution containing only 30 PIII's worth of gold. Something doesn't seem right about it. Has any gold dropped out? Did you neutralize the excess nitric with urea? Have you let the solution sit overnight ? If you have already done everything I just mentioned, you should take a few small volume samples of the solution and try several tests to determine what you are dealing with. Try more urea in one of the samples. Try evaporating another, and try one with more SMB. Hopefully one of these tests will point you in the right direction. Harold, Chris, and Catfish probably have some tips also.

Steve

Hi Destroyer:

If what I understand is correct, (the ½ HCL mixed with 16 oz (1 lb) of Sub zero), do you mean that you mixed ½ gallon of HCL to 16 ounces of sub zero. That is about the right mix. You want about 4/1 mix HCL to sub zero (sub zero is about the same thing as sodium nitrate or nitrate of soda.

Two things, P111 CPU’s don’t have very much gold. You will be lucky to get about .5 to 1.5 grams of gold from these CPU’s, just not much.

My next concern is the amount of SMB you added. You may want to make a note; you only add the equal amount of SMB to the amount of the expected gold yield. I realize that is difficult to do, so I come up with a predetermined amount of SMB according to the amount of solution and metal that I dissolve. (Best case scenario) I always let it sit for 24 hours before I siphon off the liquid from the residue. (Gold)

I never add more than 1 oz of SMB to 1 qt of HCL and 8 oz of sodium nitrate (Nitrate Soda), with 150 grams of metal regardless the gold content, except karat gold. On the above amount, 1 oz should be plenty, for like I said there is not much gold in the P111 chips.

You may want to try and neutralize the solution again. If the gold won’t fall, try to add some more dissolved urea to the solution and check for any action. My formula for Aqua Regia of this amount I use 16 oz of urea dissolved in about 500 ml of very hot water to make sure the nitrate is neutralized. This amount of chips will not use much nitric acid to dissolve and you will have to add quite a bit of urea to totally neutralize. This is where a good PH tester comes in handy. Also if you are using commercial precious metals test solution, remember that it will detect 4 parts per million. Also once you have made absolutely sure the solution is neutralized, then you may want to heat it to about 150 to 170 degrees F and this will speed up the fall of the gold. Gold will not fall unless the solution is completely neutralized.

If none of this works, you may have to start all over. The gold is still there. Just keep the forum posted on your progress and we can tell you how to start over if you have too.

Catfish


PS If you will send me your email address via PM, I will send you a spread sheet on Aqua Regia and the chemicals needed and amounts. I dont like the Sub Zero mix and my mix is a lot cheaper and readly available at your nearest feed store and Lowes.

I think that sub zero has a little more kick than sodium nitrate. At least that's what I thought when I used it.

I remember once, when I had the same trouble. I read that heating the AR to around 150F. would help to drop the gold. Well, once I got it hot, I added a little urea to it, just to see what would happen. It fizzed like crazy when heated and did not fizz at all when cold.

So now I always heat the AR to around 120F before adding the urea.

On my 2nd refining, I try to control my nitre and evaporate any off that is left. But I still add a few pellets of urea to make sure all the nitre is gone.

I agree. It is better to have too much urea than not enough. I always disolve the urea in hot water, for it works better and if you get a little to much urea, it is not a big problem.

Catfish

Following the Shor directions I added Urea till it stopped fizzing. I will try this step in hotwater im about 600ml each and let it sit and see what else I get.

I followed Shors directions which say add more SMB. So adding more Urea make since to.

I will let you know how it all turns out but. What do you mean start over like with a fresh AR bath added to the old bath? then follow the step again?

So I don't leave anyone out because it was all helpful Thanks everyone!
I am thankful for your support.

lazersteve said:

Destroyer,

3# of SMB is a lot to add to a solution containing only 30 PIII's worth of gold. Something doesn't seem right about it. Has any gold dropped out? Did you neutralize the excess nitric with urea? Have you let the solution sit overnight ? If you have already done everything I just mentioned, you should take a few small volume samples of the solution and try several tests to determine what you are dealing with. Try more urea in one of the samples. Try evaporating another, and try one with more SMB. Hopefully one of these tests will point you in the right direction. Harold, Chris, and Catfish probably have some tips also.

Steve

Click to expand...

Yes some Gold did drop out. I did not have to put much Urea in to make it stop fizzing. I did let it sit over night but if it was short on Urea and I only put it in dry and cold that maybe the problem. Maybe some testing paper would be better instead of the no fizz Shor has in the directions. But what Ph should it be 7.35 7.45. Maybe if that is right I will shoot for that number before droping Gold in the future.

Destroyer,

I seem to remember reading that Catfish said to make the pH 1. You should wait for his reply to this question to confirm my memory.

Steve

Somehow same message got posted three times.

Deleted

Destroyer:

You want the ph of the solution to be about 1.0 plus or minus .4. If the ph is around 1.0 the gold will precitate very good. I never had much luck with litmus paper. It is hard to find a paper to read that low.

If you take your solution and put it in a clear flask or beaker and when you add urea mixed in very hot water, take a glass rod and stir very good and you should see the reaction or the lack of. The solution should be auqua to green. When you apply the SMB, it should immediately turn brown after brisk stiring.

Catfish

I found some 0 to 3 pH papers on sale. Good price - about 60% off. I think they would be OK for urea.

http://www.macbicnj.com/Merchant2/merchant.mvc?Screen=CTGY&Store_Code=online&Category_Code=testpaper

A large excess of nitric will consume a huge amount of SMB. Only when the SMB has neutralized all of the excess nitric, will the gold start dropping. You have to use urea.

SilverPro:

I tried to order some of the litmus paper from the attached site and they have a minimun $25.00 order.

I also agree that urea is a lot cheaper than SMB to neutralize the AR.

Thanks for the web site. When I need some other Items , I can order some of the test strips.

Catfish

catfish said:

Destroyer:

You want the ph of the solution to be about 1.0 plus or minus .4. If the ph is around 1.0 the gold will precitate very good. I never had much luck with litmus paper. It is hard to find a paper to read that low.

If you take your solution and put it in a clear flask or beaker and when you add urea mixed in very hot water, take a glass rod and stir very good and you should see the reaction or the lack of. The solution should be auqua to green. When you apply the SMB, it should immediately turn brown after brisk stiring.

Catfish

Click to expand...

Yippeeee it worked I see that by doing as you said Gold started to drop out. I tried that on some other AR I have the same problem with and of coures it to dropped Gold as well. The Second batch I did would not dissolve any thing I put in it . So bottom Line this is fixing the problem.

Next my third batch I have some AR that had the same problem, that Shor told me to drop Tin fiol into. It still tested positive for gold. I have a dark brown mud I am not sure what all is in it now as I was told putting Tin would drop everything. Also what led me here for advice.


So My plan is with my new found learning is to get the AR I have on hand to the Ph of around one and see how it goes for drop out as I know it now has enough SMB to drop Ft.Knox.

my third batch with the gunk in it I think will need a fresh AR bath to clean up the base metals and then I am going to get the PH right. and see what it does from there.

Bottom line I feel confidant now that I have a better understanding of the importance of the Ph that I can get all the Gold out of this AR. I guess the good news is it tests positive so I know where it is and the flaw in my process that caused it in the first place.

All my batches have dropped Gold but they also tested Positive for Gold as well after SMB so I held onto all of it thinking there must be a way to get it even it I have to get an Electron Microscope and pick it out that way.
Glad I won't have to do that.


Understanding why and what the Ph does helped alot, as opposed to the directions saying put this in till it stops fizzing. That is not as accurate as testing it and getting a real number.

It's not really the pH that does it, in this case. It's the urea that does it. The urea ties up the nitric. It's just that, when you get enough urea in it, the pH happens to be 1. Actually, I guess it's a chicken and egg thing.

Those of you without pH meters might share $25 worth of 0 to 3 pH papers.

goldsilverpro said:

It's not really the pH that does it, in this case. It's the urea that does it. The urea ties up the nitric. It's just that, when you get enough urea in it, the pH happens to be 1.

Those of you without pH meters might share $25 worth of 0 to 3 pH papers.

Click to expand...

LOL I worked on an old Platform we had papers I forgot there were meters.

Destroyer:

I am glad it worked out OK for you. You came to the right place to get help. There are a number of folks on this forum that are really top drawer when it comes to recovery and refining gold. The old saying, “two heads are better than one”.

You can buy the PH testers from eBay for about $25.00. Be sure and get a pack of 1.0 buffer solution to calibrate the tester.

As for as the term “neutralizing the solution”, this is kind of a misnomer. We often think of a neutral PH of 7.01. In this case this is not true. All you need to do is basically neutralize the Nitric acid in the solution. The solution Ph actually winds up about 1.0. (As SilverPro, so elegantly articulated). This is a bench mark to let you know that the nitric acid has been neutralized. You still have a strong presence of hydrochloric acid in the remaining solution. It would take a lot of baking soda or wood ash to bring the solution to a 7.01.

When you have dropped all the gold out and if you are through with the spent AR, then you can add an old hard drive or floppy drive aluminum housing in the solution for a couple of days and drop the copper out and than add one part water and baking soda or any good base and then neutralize the solution to somewhere around 7.0 ph and discard. It is an inert liquid then. If you really want to, you could drop the lead out, if you thought you needed too, before diluting and neutralizing the solution.

Lots of luck,

Catfish

I prefer pH papers over a pH meter, If I can get the right range. I keep them in my pocket. Use pieces only about 1/2 long and a roll will last a long time. The meters are somewhat user dependent. It's possible to get bad readings if you don't do things right - like contaminating the buffer solution.

You are absolutely right about the meters. It took me a while to remember that each time I used the PH meter, I had to recaibrate with acid buffer solutions each time I used the meter.

But after a while you get to be able to just look at the solution while adding disolved urea, to be able to see if it is neutralized. I always double check to make sure I get all the gold out.

The paper would be much faster.

Ctafish