# Nitric acid



## mido_akkad8 (May 4, 2021)

Greetings 
How much nitric acid needed to work on 200g gold plated pins for gold refining 
Without counting the nitric that used for making AR


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## Martijn (May 5, 2021)

No nitric for deplating. AP or sulfuric stripping cell is what i use. When you use nitric, the cost will be higher than the yield. 
For 200 grams of copper or brass pins, you will need 800ml of nitric. 

From 200 gram plated pins, you can expect 0.5 grams of gold. Or less. Depends on the thickness of the plating and the size of the pins. Thinner pins, bigger yield. 

Martijn.


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## mido_akkad8 (May 5, 2021)

Martijn said:


> No nitric for deplating. AP or sulfuric stripping cell is what i use. When you use nitric, the cost will be higher than the yield.
> For 200 grams of copper or brass pins, you will need 800ml of nitric.
> 
> From 200 gram plated pins, you can expect 0.5 grams of gold. Or less. Depends on the thickness of the plating and the size of the pins. Thinner pins, bigger yield.
> ...


Thank you for the satisfying answer you just gave me
The thing is syria is a war zone so it’s hard to get the AP or Sulfuric striping cell , although i do have sulfuric acid would it work?
Tip :The cost of 1L sulfuric acid witch i have is much higher than what would I pay for 1l nitric acid 


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## Martijn (May 6, 2021)

I have stripped 4 kilo's of pins in 200ml H2SO4 96% and it's still good to use. Just let the gold settle and siphon off the clear acid or use a pipette. 

Be very carefull with concentrated sulfuric. Keep water away from the cell and cover it when not in use. It draws moist from the air if left open. 
Water in the acid will cause copper to dissolve. 
Use a pyrex beaker with a plastic lid as the cell. 

Study it first very well. 

Nitric is used up in one go. It's much harder to recover (part of) what you've used in the process. 

Martijn.


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## Ray Levi (Nov 9, 2021)

mido_akkad8 said:


> Greetings
> How much nitric acid needed to work on 200g gold plated pins for gold refining
> Without counting the nitric that used for making AR
> 
> ...











JSP® Nitric(HNO3)Acid 1/2liter 500mL(16.9oz)Lab Grade Gold Refining FREE SHIP | eBay


1/2 LITER (16.9oz) 500lL Concentrated Nitric Acid HNO3 67% Reagent Grade. Polyethylene (PTFE, LDPE) and even HDPE are unsuitable for storing Nitric Acid. Storage Temperature: < 75ºF. When diluting concentrated acids like Nitric Acid, always add the acid to water slowly.



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## Martijn (Nov 9, 2021)

1: you don't need lab grade gold refining nitric to dissolve base metals. Which makes absolutely no sense by the way..
2: 200gr of pins will yield about 0,5 grams of gold, if your'e lucky. so a couple of hours/days work and health and environmental risks further for what?
3: Roughly 4ml of nitric is needed for every gram of base metals, equals roughly 800ml of nitric for 200gr of pins. With nitric acid @ 50 dollars per 500 ml you will loose money: 

2 bottles of 500 ml HNO3, 100 dollars at least for 0,5 grams max. of gold which eqauls about 25 dollar. 
shall I give you my bank account number? You can throw away your surplus money there please. 

Really, STOP. and study.


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## Alabama938 (Nov 9, 2021)

What do you use for a basket, trying to devise that has been my main deterrent from attempting a cell


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## Martijn (Nov 9, 2021)

Copper wire weaved into a basket for larger pieces. And a piece of fine copper mesh draped around a copper wire frame like a sieve for really thin pins. 
I had a bunch of copper wire twisted together to push down with on the pins in the basket and make better contact on different points to get the last bits off. Connected to the positive lead off course. 
Have an Amp meter in series to see the current drop. That's when there's no more gold being stripped.


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## Alabama938 (Nov 9, 2021)

That is awesome construction! Thx


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## Martijn (Nov 9, 2021)

And keep any water away from the cell!! No spray bottle anywhere near it! If a drop of water falls in the acid, it can react violently. 
I also put the glass or beaker in a stand with a hole for the glass cell so i can't knock it over. 

These glasses are from cocoa spread. The lids are neccessary to keep moist out of the acid when its not in use. Catch bassin was removed for the photo.


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## GoIdman (Nov 10, 2021)

mido_akkad8

To prepare AP you can use regular descaler solution which you can find at any general store where they sell food and some basic household chemicals too, and use 3% peroxide which you can find at any pharmacy whatsoever. The descaler contains between 15% and 20% of HCl. I use it as it is no huss and fuss with the pharmacy H2O2 and it works just fine. The total cost is around 1,5-2 $ (1$ the 1l descaler, 0,5-1$ for 300ml 3% H2O2)
This is the simplest and cheapest method I have found so far to create AP solution.

Be safe and good luck.

Pete.


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## cejohnsonsr1 (Nov 10, 2021)

Muriaric acid from a hardware store (Ace) is HCL and is suitable for both AP and AR.


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