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SapunovDmitry

SapunovDmitry

Well-known member
Joined
Dec 7, 2007
Messages
332
Location
Moscow
Guys....Again i have a problem with the cell.
This time i use lab grade sulfuric without any buffers,6-12 v power supply for sulfuric acid battaries "Piece of mind PM674", lead negative electrode and pins as positive electrode.
I dillute sulfuric to 80-85% by volume.
And i put pins into the cell. They deplate in 3-5 sec and then, when i take them out of the cell they are copper pink.
I use pins that 110% have nickel layer. If i leave them in the cell they start buzzing and bubble untill all the copper is eaten....
I thought if i use 6 volts deplating process will stop after all the gold has been removed, and i will see nice nickel surface.
When i use microscope x10 to look at the pins i have just deplated i see a copper coloured "moon" surface with large number of "craters".
Can this be glycerine? I don't know what to think after all i've done......
 
But it does deplate pins. The only problem is that it "deplates" everything.
Did you ever had something like that Steve?
More dilluted sulfuric attacks nickel?
Does the nickel layer always stay in a right setup?
 
Even concentrated sulfuric will attack nickel slowly - the more dilute, the faster the nickel will dissolve. As Steve said, don't dilute with more than 10% water, by volume, or you will start dissolving copper. I prefer only a 5% dilution, since the strong sulfuric will also absorb some moisture from the air.

You're right. The weaker H2SO4 you used will deplate the pins. Even 35% battery acid will deplate the pins. However, it will also dissolve the copper at 100% efficiency.

This is a balancing act. You need a little water to speed up the reaction. Too much water and you will dissolve the copper. This defeats the whole purpose of the stripper, which is to strip the gold without eating the copper.
 
Since were discussing cell issues.....

my cell seemed to slow down, after only about 4 - 6 hrs use. I did about 1/4 lb CPU Lids and a bunch of "other" things "you know the look at what my new cell can do part...


i used "clobber" drain cleaner for the acid i think it was 97% sulfuric

and after some further advisement, i toned it down from the 10A setting to 2A becuase it was getting HOT

so as per Steves videos, i removed the black powder, to find about 5.5 grams, i used the bleach, HCL method to disolve, and it still appears rather dark, compared to other powders i have delt with.

I am not complaining about the yeild, although next time i want the cell to run longer to get a bigger yeild, as thats alota work (more like waiting) to get everything diluted and siphoned off.

so questions:

why did the cell slow down?

is it normal to have to refine the black powder more than twice?

what exact brand of drain cleaner did steve use and where does he get it?

what role does the glycerin play in all this? (i didnt use any)

what can i do in the future to prolong the cell acid ?

as always thanks in advance Ryan
 
Thanks guys gor help. I will try 93-95% acid tonight and will bring microscopic pics of what has happened with my previous pins.
I always add a teaspoon of glycerine, cause acid doesn't splash too much if you do so. If you don't add it nothing bad will happen. It won't affect the process. It will simply result in slightly bigger acid bubbles from your pins.
 
Gold Trail said:
why did the cell slow down?
Click to expand...
You would benefit from reading the original patent on this process.

As I understand the function, in the proximity of the anode (your pins), persulfuric acid is formed by the current. It is capable of dissolving gold, silver and other precious metals. As the electrons leave the proximity of the anode, the persulfuric acid reduces to sulfuric acid, which is not capable of dissolving these metals, so they precipitate as the black residue which is your target.

Armed with this idea, you can see that as the values are removed, the material loses its ability to emit electrons, so the current level falls. When you become familiar with your particular cell, it's possible you can judge when you have removed the preponderance of the values by the amperage involved.


is it normal to have to refine the black powder more than twice?
Click to expand...
Did you do anything to improve the quality of the powder before it was dissolved?

I have long maintained that it should be incinerated, then given a boil in nitric acid to remove unwanted substances. After a careful rinse (tap water is acceptable), it can then be dissolved, and processed for recovery of values. If you have not performed these two operations, it's entirely possible you are dissolving a great deal of base metals with the values, a portion of which will report in the final product, especially if you do not use a good washing procedure.

Harold
 
Gold Trail said:
why did the cell slow down?
Click to expand...

How large is your cell? Normally, the amps will drop during the stripping and, when the parts finish stripping, the amperage will go to zero. However, when too much gold builds up in the solution, the gold powder, being metallic, will create a partial short, the amperage stay at a constant level and will not eventually go to zero (it can actually increase), and the parts can stop stripping. When this happens, it's time to harvest the gold.

Based on the amount of material you've run and the fact that you have high amperage, it sounds like that's what is happening. Either harvest the gold more often or get a bigger tank.

I never used glycerin and it's not used in the patent. At some point in time, someone added it for some reason, although no one seems to know why. It doesn't seem to cause any problems.
 
Harold V..... the incineration skipped my mind.... i can blindly recover gold from most escrap, but that incineration ALWAYS seems to get forgotten..... my bad. question answered

my cell holds about 2 qts acid, i thought i could saturate it more than 4-7 grams...

GSP = i am always game for a bigger tank

thanks Ryan
 
Ryan,
I use Rooto brand drain cleaner and it worked great. I think that is what Steve uses also, at least when he made the videos.
Jim
 
Gold Trail,

You're right, 1/2 gallon should hold 4 to 7 grams of gold. I don't remember having any problems until I had about a tr.oz. of gold per gallon. As the parts are stripping, does the amperage decrease? When the parts are stripped, does the amperage go to zero? Can you detail what the amperage does, from when you put the parts in until you take them out - both when the solution was fresh and now? When the gold settles, what color is the solution? Green?

You didn't seem too sure about the strength of the sulfuric you are using. Did it say 97% on the label? Did you add any water to the sulfuric? If it is weaker than what you think, you could have problems. Also, there are additives in the drain cleaners. Maybe, "Clobber" has something in it that causes problems.
 
good thing were having a slow day at work here....

when i started the cell, using the 12 volt 6 amp setting, when the pin was submersed, it would got to 6 A then trickle down to 0 amp

after awhile the amperage would shoot to 6 when the pin was submersed, then wouldnt drop below 2ish and as time went on, i noticed the pins would take longer and longer to strip.

after i preciptated the gold from the hcl / bleech mix ( wich was yellow) the remaing fluid was a brownish color

and the powder was still dark, but I forgot to incinerate, which may have led to the drag down.



JIMDDOC which store stock the rooto brand? ( ihate buying chems on line due to the Hazmat shipping surcharge)

thanks Ryan
 
Actually, I was asking the color of the sulfuric solution.

It sounds like the solution was overloaded with gold, since the amps wouldn't drop below 2.
 
I found mine at a local Ace hardware, they had quarts and gallons.
Gallons were about $20 and a better deal than the quarts.
I haven't seen it in Lowes or Home Depot, but I saw one brand that comes sealed in a plastic bag, that is a hint to further check out the sulfuric percentage whatever brand it may be.
Jim
 
GSP, the color of the sulfuric solution was dark brown, almost black at the time i thought things were going wrong

but from the looks of the responses and some reading i did in the gold refining handbook, vol 1 and 2 (keep em right next to Hoke, btw) things are normal and where they should be.

i am going to find a bigger tank, while 6 ish grams wasnt bad at all for the small amount of materials i stripped, sulfuric acid isnt cheap, it takes quite a bit of time to seperate the powder from the acid, ect.

i would prefer to do it once in a while and see a troy ounce plus for the time involved. so off to find a suitable 2 gallon tank it is.

thanks for all your input

Ryan
 
Here is an MSDS sheet on clobber. Says it is just acid and water mix. I use it on a regular basis and it is the strongest mix for a drain opener that you can use IMHO.

Link to MSDS sheet:
http://herchem.com/CanadianENGMSDS/MSDS342%20Clobber.pdf

3. COMPOSITION/INFORMATION ON INGREDIENTS
Component CAS Number Wt/Wt % OSHA PEL ACGIH TLV Other Limits

Sulfuric Acid 7664-93-9 93 1 mg/m3 1 mg/m3 15 mg/m3-
IDLH

Water 7732-18-5 7 N/A N/A N/A


HMIS Hazard Rating: 3 0 2 H


Haven't seen this posted so hope it helps answer some questions on the clobber issue.
 
Hello:

Just downloaded the msds for clobber and then read what it had to say.

For disposal is says do not dispose of in the sanitary sewer system. What a joke!!! It is a drain cleaner meant to be put down the sewer pipe to disolve the clogs. I wonder who writes these things. Must be from some other planet! :lol:
 
Gentlemen! I'm back with some closeups of strong vs. weak acid job on pins.
As you can see 80% acid eats gold, nickel and slowly eats copper leaving moon "craters". 93-95% Acid doesn't affect nickel too much. It just stops after eating gold. Images are x 10-20 magnified. It is enough to see the surface. If you use larger magnification you won't see the whole thing, so i tried to use smallest magnification possible in my setup.
 

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