# Anywhere to buy nitric reasonably cheap?



## ssharktu17 (Dec 10, 2021)

Everywhere I check it is insanely high. Any good places to buy? Maybe even in bulk. I am trying to refine scrap silver but the costs so far seem way higher than just selling it to a refiner.


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## ssharktu17 (Dec 10, 2021)

Maybe it’s better to distill it?


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## orvi (Dec 10, 2021)

ssharktu17 said:


> Maybe it’s better to distill it?


Depend on how you look at it. If you add the value of your time, than distilling is big no no. From my experience, distilling nitric from nitrate/sulfuric acid is nasty process, require ALL GLASS apparatus (any plastic/rubber except PTFE will disintegrate in short time), and proper fume hood. Not advised to do on large scale, cleaning of the sulfate cake from the flask is often painful, and imagining how to prepare like 5 litres... man, never  Maybe the only relatively doable distillation what comes to my mind is from reaction of calcium nitrate tetrahydrate with sulfuric acid and controlled ammount of water. Keeping excess of sulfuric (like 0,5-1 M sulfuric in the end liquor) will lower the solubility of formed gypsum. Tricky to do it well, filtering is also painful (filter paper will probably die, fritted glass is better choice), not mentioning you will never get full recovery of acid, washes contain some CaSO4 as well. And still, contamination with sulfuric acid could be real even after distillation. Also not advised, only in the case of real nitric crisis  if you attempt this, be careful and start with small ammount of reagents (eg less than 50g of nitrate) to see what you will be dealing with. Add sulfuric slowly. And fume hood is strongly advised.
Best option is to buy it. What is the price for liter ? just for comparison, here where i live the cost (like 2,5 euro for liter, bulk is far cheaper) is not the issue. Public sale of nitric here is prohibited completely.If the feedstock is sterling, silver cell is maybe the best solution. If source is something like contact points, thick silver plated items, then you could eat up base metals with HCl/air, leaving silver and AgCl mostly undissolved. Then you could melt it and refine in the cell


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## ssharktu17 (Dec 10, 2021)

Well sounds like a lot of trouble to distill it! Thanks, Here it seems to be quite expensive like $4,500 USD for a 55g drum of it. The prices I am seeing per liter are absurd Like $50 USD. Maybe I will have to research this silver cell. I have mostly silver between 75-95%.


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## Elemental (Dec 10, 2021)

__





nitric | Duda Diesel Alternative Energy, Chemicals & Industrial Supply Store






www.dudadiesel.com





This is who I use for nitric. 

Elemental


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## orvi (Dec 10, 2021)

ssharktu17 said:


> Well sounds like a lot of trouble to distill it! Thanks, Here it seems to be quite expensive like $4,500 USD for a 55g drum of it. The prices I am seeing per liter are absurd Like $50 USD. Maybe I will have to research this silver cell. I have mostly silver between 75-95%.


I mean, it could be done. If you have no other option, but to use nitric, which is 50 bucks per liter, than i will spend a minute thinking, how to get it cheaper. But unless you have some experience with general distillation, ground glass apparatus greased with concentrated sulfuric acid... I dont think it is a good idea. Hot nitric vapour is insanely nasty stuff. So are the contents of the boiling flask, mostly sulfuric/nitric acid at nearly 200°C. Overheating could cause bumping, leading to the flask rupture and... big bad  If you will need like few liters, then flask should be like 2-4 liter in capacity... Not the safest operation.
75% is relatively low for the cell. With 90% it could be possible, but purer is better. If you are aiming on 99+.
Some chemical feed for refining operation is necessary, not every chemical could be eliminated. Deviating from well established procedures causes problems and many times results in tedious separations/filtrations/poor purity of products.


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## ssharktu17 (Dec 10, 2021)

orvi said:


> I mean, it could be done. If you have no other option, but to use nitric, which is 50 bucks per liter, than i will spend a minute thinking, how to get it cheaper. But unless you have some experience with general distillation, ground glass apparatus greased with concentrated sulfuric acid... I dont think it is a good idea. Hot nitric vapour is insanely nasty stuff. So are the contents of the boiling flask, mostly sulfuric/nitric acid at nearly 200°C. Overheating could cause bumping, leading to the flask rupture and... big bad  If you will need like few liters, then flask should be like 2-4 liter in capacity... Not the safest operation.
> 75% is relatively low for the cell. With 90% it could be possible, but purer is better. If you are aiming on 99+.
> Some chemical feed for refining operation is necessary, not every chemical could be eliminated. Deviating from well established procedures causes problems and many times results in tedious separations/filtrations/poor purity of products.


Definitely sounds like I need to just shop around for the cheapest nitric in the country and buy in bulk. Thanks for the excellent explanation much appreciated!


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## orvi (Dec 10, 2021)

Elemental said:


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lucky you  10 liters for 150... very good price. i once thought about getting license, but this would be dive into the pile of s*it here.
for liter, it is like 2,50+-, but tech grade 50% stuff in bulk (1000 L) is going below 60 cents.
my whole refining is impaired by this restriction. practically speaking, only HCl is sold restriction-free for public here. luckily, i have access to some more "exotic" chemicals, mostly old stuff... to substitute the nitric. hence my experience with making it  that was like 5 years ago, i have done it the last time.

Edit: bad maths, i missed one zero :/ anyway, if i could get it for 15/liter, i would go all in


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## ssharktu17 (Dec 10, 2021)

Ok maybe I am missing something but most searches are saying 150ml nitric to dissolve one ounce of sterling? Even 10liters at $150 ($200 after taxes +shipping) is almost $3 per ounce to dissolve??


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## ssharktu17 (Dec 10, 2021)

Elemental said:


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Do you melt a lot of sterling?


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## orvi (Dec 10, 2021)

ssharktu17 said:


> Ok maybe I am missing something but most searches are saying 150ml nitric to dissolve one ounce of sterling? Even 10liters at $150 ($200 after taxes +shipping) is almost $3 per ounce to dissolve??


I think it should be far less. If we talk about dissolving pure silver, idealized reaction would be:

Ag + 2 HNO3 ---> AgNO3 + NO2 + H2O

So 2 moles of nitric required for one mol Ag. One mol Ag is 107,9 g. Two moles of nitric required (68% w/w) are 185,3 g = 123 ml. 
So you can ideally dissolve 107,9/31,1 = 3,47 ozt of Ag with 123 ml of concentrated nitric. 
In real world, some nitric evaporates, also some NO2 would react with oxygen back to nitric again... But you lose more than you gain. Also sterling is mostly 92,5%, so 7,5% of mainly copper is inside. Copper require two times more nitric (molar scale) than silver, but it is more complicated. 
For 63,5g copper you need 246 ml of nitric. Ideally. In this case, number is usually lower than this, due to deeper reduction of nitric acid. But not always. Generally lower temperature and dilution help nitric to be reduced partly to NO, not NO2, gainig two electrons more.
Concluding 100 g of sterling require 105,5 ml nitric for silver and 29 ml for copper = 134,5 ml of 68% nitric.
That is roughly 42 ml of 68% nitric for 1 ozt of sterling. In ideal world.
If my math is incorrect, please correct me.

If you have access to hydrogen peroxide, you could compensate the loss of NO2 by adding stronger hydrogen peroxide to the reaction, which convert most of the NO2 back to nitric acid, thus regenerating your precious reagent. But i never done this on scale-up, so i will be careful with this. Maybe somebody more experienced, who done this shed more light to this  because mixing two strong oxidants together... For the first hearing, it sound somewhat dangerous.


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## Elemental (Dec 10, 2021)

ssharktu17 said:


> Do you melt a lot of sterling?


I am new to this but have about 3kg of fine silver that I have refined so far. The chemistry isn’t too complex for me as I am school trained in it. Melting, pouring, etc has been where my learning curve has been steepest. As part of learning and experimenting I’ve used about 5 liters of nitric. 

My apologies for providing an American company. I saw your location was LA and assumed Los Angelos, California. Where specifically are you?


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## Elemental (Dec 10, 2021)

orvi said:


> lucky you  10 liters for 150... very good price. i once thought about getting license, but this would be dive into the pile of s*it here.
> for liter, it is like 2,50+-, but tech grade 50% stuff in bulk (1000 L) is going below 60 cents.
> my whole refining is impaired by this restriction. practically speaking, only HCl is sold restriction-free for public here. luckily, i have access to some more "exotic" chemicals, mostly old stuff... to substitute the nitric. hence my experience with making it  that was like 5 years ago, i have done it the last time.
> 
> Edit: bad maths, i missed one zero :/ anyway, if i could get it for 15/liter, i would go all in


No license was required to get 10 liters shipped to my house. Although when they sent the first shipment they sent me 5 gallons of pure acetone. They were quick to fix it which is why I still recommend them. (Plus they let me keep the acetone!)

I’m sure I’m on some watchlist now but who isn’t. (That’s a joke Agent Anderson…)


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## ssharktu17 (Dec 10, 2021)

Elemental said:


> I am new to this but have about 3kg of fine silver that I have refined so far. The chemistry isn’t too complex for me as I am school trained in it. Melting, pouring, etc has been where my learning curve has been steepest. As part of learning and experimenting I’ve used about 5 liters of nitric.
> 
> My apologies for providing an American company. I saw your location was LA and assumed Los Angelos, California. Where specifically are you?


I am in the US. Louisiana. Thanks for the source!


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## orvi (Dec 10, 2021)

Elemental said:


> No license was required to get 10 liters shipped to my house. Although when they sent the first shipment they sent me 5 gallons of pure acetone. They were quick to fix it which is why I still recommend them. (Plus they let me keep the acetone!)
> 
> I’m sure I’m on some watchlist now but who isn’t. (That’s a joke Agent Anderson…)


sweet


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## ssharktu17 (Dec 10, 2021)

orvi said:


> I think it should be far less. If we talk about dissolving pure silver, idealized reaction would be:
> 
> Ag + 2 HNO3 ---> AgNO3 + NO2 + H2O
> 
> ...


Interesting Thank you for working out the science for me! That makes more sense. Also, wow copper consumes a lot. I have a fair amount of 75% and 80% silver so that is going to consume a lot more. Interesting Idea with H2O2 I will definitely have to research that as well! So I could probably say close to 50ml per ozt of sterling which would cost me $1 per ozt in nitric still not too cheap but getting reasonable.


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## Nickster (Dec 11, 2021)

I purchase my nitric from ebay, how they get around special handling charges with shipping I'm not sure. But it's always sent fast and well padded.


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## Hombressino (Dec 11, 2021)

I recently found a video of NurdRage, a person probably well known to the community. He shows how to recycle HNO3 from copper nitrate, And even copper itself. Very instructive with lot of chemistry background information. Plenty of us would probably found it helpful or ať least enlightening:


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## Elemental (Dec 11, 2021)

Hombressino said:


> I recently found a video of NurdRage, a person probably well known to the community. He shows how to recycle HNO3 from copper nitrate, And even copper itself. Very instructive with lot of chemistry background information. Plenty of us would probably found it helpful or ať least enlightening:



An interesting video, but a lot of extra work and a new waste stream is created (copper sulfate + sulfuric acid). I am curious as to what the concentration of his final nitric acid was before fractional distillation. My assumption is most of what he distilled was really water with <1M nitric acid left over. This appears to be hours worth of chemistry just to regain a little bit of nitric acid. Don't get me wrong, definitely useful for those of you in countries where purchasing nitric acid off the shelf is not permitted, but as it's been stated here before, time is also a cost, not to mention a new reagent (sulfuric acid), waste stream, distillation and fractional glassware, etc. 

As an aside, when he displayed his glassware that was not clean (covered in fibers and the solution sticking to the side walls of the e-flask, a scale covered in filth, and a dirty bench, it did raise a red flag and show a lack of lab cleanliness. I would hate to rest my arm on his lab bench, not knowing what I might be getting on my lab coat. The chemistry all sounded pretty good though and he put a lot of work into this. Thanks for sharing @Hombressino

Elemental


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## orvi (Dec 11, 2021)

Elemental said:


> An interesting video, but a lot of extra work and a new waste stream is created (copper sulfate + sulfuric acid). I am curious as to what the concentration of his final nitric acid was before fractional distillation. My assumption is most of what he distilled was really water with <1M nitric acid left over. This appears to be hours worth of chemistry just to regain a little bit of nitric acid. Don't get me wrong, definitely useful for those of you in countries where purchasing nitric acid off the shelf is not permitted, but as it's been stated here before, time is also a cost, not to mention a new reagent (sulfuric acid), waste stream, distillation and fractional glassware, etc.
> 
> As an aside, when he displayed his glassware that was not clean (covered in fibers and the solution sticking to the side walls of the e-flask, a scale covered in filth, and a dirty bench, it did raise a red flag and show a lack of lab cleanliness. I would hate to rest my arm on his lab bench, not knowing what I might be getting on my lab coat. The chemistry all sounded pretty good though and he put a lot of work into this. Thanks for sharing @Hombressino
> 
> Elemental


NurdRage have a wonderful channel, i gained so much watching his videos. Very illustrative, clear and full of explanation what is really happening  also, his series on the making of Pyrimethamine are just perfect. Making fairly complicated pharmaceutical from household chemicals 
But most notable thing what he issued, optimized and share with public was process of making sodium without electrochemistry.


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## ssharktu17 (Dec 12, 2021)

Sounds like a silver Cell would be far more economical considering the price of nitric.


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## Elemental (Dec 12, 2021)

I use a silver cell for after chemical refinement to get the silver from ~98-99% pure to four 9's fine silver. Putting sterling silver into a silver cell will quickly foul the electrolyte with copper nitrate.


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## ssharktu17 (Dec 12, 2021)

Elemental said:


> I use a silver cell for after chemical refinement to get the silver from ~98-99% pure to four 9's fine silver. Putting sterling silver into a silver cell will quickly foul the electrolyte with copper nitrate.


Ah ok so then it is only used for getting to 9999 silver really. So the most economical way to refine sterling to 999 is dissolving with nitric acid.


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## Elemental (Dec 12, 2021)

Here is the basic recipe that I follow. Although I have a spreadsheet now to calculate distilled water/acid/sterling ratios. 

Elemental's Steps for Refining Silver

Melt sterling silver and slowly pour into water basin to make silver corn-flakes. (This step can be skipped, but dissolving the silver takes longer)
Measure out 110 grams of silver corn-flakes and place in a clean 500mL beaker.
Add 150mL of distilled water to beaker.
Heat the beaker on a hot-plate to 80 degrees Celsius
Add 50mL of 70% concentrated nitric acid
Cover with a watch glass allow reaction to proceed until no more brown fumes are generated.
Add 50mL of 70% concentrated nitric acid
Cover with a watch glass allow reaction to proceed until no more brown fumes are generated.
Add 50mL of 70% concentrated nitric acid
Cover with a watch glass allow reaction to proceed until no more brown fumes are generated or all the silver is consumed.
If all the silver has been consumed, add more silver in 5-gram increments until no more fumes are generated and there is silver in the bottom of the beaker. (This will ensure all the nitric is used up)
Decant solution into a clean 1,000 mL beaker.
Add 150mL of distilled water to beaker. (Don't be afraid to use extra water here, if your silver nitrate is too concentrated, it forms a shell on the copper wire and stalls the reaction)
Add a coil of copper grounding wire to the beaker by hanging it above the bottom using nylon string, agitate or stir with magnetic stir-bar.
Add 5 drops of concentrated nitric acid to the beaker. (This helps with starting the cementation process)
Allow reaction to proceed until no more silver cements out of solution on a clean piece of copper wire. (Or take a few milliliters of solution in a test tube and add a drop of hydrochloric acid or sodium chloride, a white cloud indicates silver still in solution, note: this test is very sensitive)
Decant copper nitrate solution into a silver stock pot. Place used coil in stock pot
Wash silver cement multiple times with hot water until solution is clear. Add washing water to stock pot.
Dry silver cement in small crock pot
Transfer silver “cement” dust to a melting crucible and melt at 2,000 degrees Fahrenheit
Pour purified silver into graphite bar mold and drop into water basin to make silver anode bars.
Setup a silver cell and generate purified silver crystal. Need to mix electrolyte while crystals form.
Electrolyte: 150 grams of silver dissolved in nitric and diluted to one liter for electrolytic solution
Place anode bars in anode bag/basket, push 3.5v across anode bar and stainless steel cathode (this will be >3.5v on the power supply
Monitor daily for any long crystals(knock these down) and how blue solution gets from dissolved copper.
A drop or two of nitric acid daily assists with keeping silver in solution
Run all anode bars until stainless steel bowl is full of crystal or you run out of anode bars.
Decant used electrolyte, dilute with distilled water and add copper wire coil to cement out remaining silver, re-use cement for next electrolyte solution or add to next batch of sterling processing.
Rinse crystals well in plenty of hot water
Dry, melt and pour bars of four 9's silver using tabletop furnace and graphite mold
Weigh, stamp, and stash away for daughter's college fund.
Clean all the glassware, silver cell, and do waste processing!
You can dissolve some crystals in nitric acid. It should be crystal clear. You can then add a drop of ammonium hydroxide to a test sample and if it turns blue it has copper in it.

Elemental


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## FrugalRefiner (Dec 12, 2021)

Elemental said:


> I use a silver cell for after chemical refinement to get the silver from ~98-99% pure to four 9's fine silver. Putting sterling silver into a silver cell will quickly foul the electrolyte with copper nitrate.


But it is still more cost effective than dissolving the feed stock in nitric, cementing, melting to cast anodes, then running in the cell. Sure, sterling will build up the copper level faster than 3N feedstock, but what is the cost for nitric and copper to get the feedstock to 3N?

For lesser material, you can run it as a two step operation. The first cell is a break down cell. Monitor it as it runs. As copper builds up, replace part of the electrolyte to keep it running. Where I live, electricity is cheaper than nitric. Then you can melt the crystal for anodes and run it through a second cell if needed.

Dave


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## Elemental (Dec 12, 2021)

Dave,

You're right about it being cheaper to just run a couple of parallel silver cells to get from sterling to fine silver. For me it was more about a hobby that let me do wet chemistry than it is as a side business (all my refined metal is being stashed away for my daughter's college/wedding fund). As a hobby I don't really expect to make money on it, nor invest the time to as efficient as possible (although I certainly do try my best). I'll give the dual-silver cell process a try next spring when I open the lab back up. It'll be something new to try and document. Thanks for pointing it out. I'll also be starting my first attempt at gold refining next spring as well. I'm really looking forward to getting to refine the "real" metals!

As for a bit of math on costs, I spent $230.64 on 10L of conc. nitric acid. To refine 3kg to four 9's fine silver, I've used half of it (5L), so about a $100. (Some of that was used in simple experimentation as well.) Below is my invoice for nitric acid:

Product Name: Nitric Acid, 4 x 2.5L, 67.2% Concentration by Weight,
4 x 2.5L PVC-Coated Bottles
Item#: na10l
Unit Price: $208.02
Quantity: 1
Shipping Method: Fedex Home Delivery S&H

Fedex Home Delivery S&H: $22.62
Grand Total: $230.64

Elemental


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## orvi (Dec 12, 2021)

Elemental said:


> Here is the basic recipe that I follow. Although I have a spreadsheet now to calculate distilled water/acid/sterling ratios.
> 
> Elemental's Steps for Refining Silver
> 
> ...


Very nicely written. Good lead for anyone attempting this sequence

In terms of evaluating cost effectiveness... If I purchase nitric here for registered company, it would cost somewhere around 2,5 euro per liter (65%), so i will definitely go for nitric path in the start.
But the idea with two cells in series is appealing  as long, that i could only dream about steady supply of this cheap nitric  or better said, any nitric


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## voidforged (Dec 12, 2021)

I get my nitric from Legend Mining in Reno, there are no shipping/hazard fees if you choose in-store pickup. $167 for a case of 6 2.5L bottles. I just place an order about a month ahead of when I make a trip up there and pick it up while I'm already in the area for other things. I would look into similar mining supply companies in your area.


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## ssharktu17 (Dec 12, 2021)

FrugalRefiner said:


> But it is still more cost effective than dissolving the feed stock in nitric, cementing, melting to cast anodes, then running in the cell. Sure, sterling will build up the copper level faster than 3N feedstock, but what is the cost for nitric and copper to get the feedstock to 3N?
> 
> For lesser material, you can run it as a two step operation. The first cell is a break down cell. Monitor it as it runs. As copper builds up, replace part of the electrolyte to keep it running. Where I live, electricity is cheaper than nitric. Then you can melt the crystal for anodes and run it through a second cell if needed.
> 
> Dave


Great point this really sounds more realistic. Especially considering nitric prices could even soar higher along with shipping and taxes... Nitric adds up fast if you are going through a lot of sterling.


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## ssharktu17 (Dec 12, 2021)

voidforged said:


> I get my nitric from Legend Mining in Reno, there are no shipping/hazard fees if you choose in-store pickup. $167 for a case of 6 2.5L bottles. I just place an order about a month ahead of when I make a trip up there and pick it up while I'm already in the area for other things. I would look into similar mining supply companies in your area.


That sounds a lot more reasonable. Local pickup would definitely be the way to go.


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## Ray Levi (Dec 12, 2021)

ssharktu17 said:


> That sounds a lot more reasonable. Local pickup would definitely be the way to go.


If you want to buy


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## Ray Levi (Dec 12, 2021)

This is a link to the least expensive Nitric Acid you can buy. It's on Ebay and there is no hazardous surcharge. 








JSP GT544 Concentrated Nitric Acid - 33.8oz for sale online | eBay


Find many great new & used options and get the best deals for JSP GT544 Concentrated Nitric Acid - 33.8oz at the best online prices at eBay! Free shipping for many products!



www.ebay.com


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## voidforged (Dec 12, 2021)

Leoesch said:


> This is a link to the least expensive Nitric Acid you can buy. It's on Ebay and there is no hazardous surcharge.
> 
> 
> 
> ...


That's not even close to the least expensive you can buy it for. And its kind of sketchy to me that the seller reviewed their own product.


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## ssharktu17 (Dec 12, 2021)

voidforged said:


> That's not even close to the least expensive you can buy it for. And its kind of sketchy to me that the seller reviewed their own product.


Haha ya that is one of the highest prices of seen! He gave himself 5* review lol.


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## kurtak (Dec 13, 2021)

orvi said:


> I think it should be far less. If we talk about dissolving pure silver, idealized reaction would be:
> 
> Ag + 2 HNO3 ---> AgNO3 + NO2 + H2O
> 
> So 2 moles of nitric required for one mol Ag. One mol Ag is 107,9 g. Two moles of nitric required (68% w/w) are 185,3 g = 123 ml.



Concerning - "how much acid (nitric) it takes to dissolve a given amount of metal (silver)" - there needs to be some clarification made here

When dissolving metal with acid (nitric in particular) there is NO SUCH THING as "it takes" or "you need" or "required"

Whether trying to calculate it by moles of acid to moles (of a given) metal --- or trying to calculate it by X ml acid per X grams metal (when referenced as - required, it takes or you need) you will almost always if not always be wrong

Why ? --- because those are "rules of thumb" not "absolute laws"

The "actual" amount of acid it takes to dissolve a given amount of metal will depend A LOT on the conditions involved in dissolving the metal

Depending on the conditions it can & will "more likely" ether take more acid or less acid to dissolve your given amount of metal & that can very - more or less - by a lot

Therefore - the advice of how much acid it takes to dissolve a given amount of metal should NEVER be given in terms of - it takes or you need or required --- that will only lead to people "wasting" acid

Therefore - using "rule of thumb" numbers the advice should ALWAYS be that it takes or you need or it requires ABOUT - X amount acid to X amount metal

Example; - the advice - often given - is that "IT TAKES" 1.17 mil 70% nitric plus 1.17 ml distilled water to dissolve 1 gram of silver --- & that just is not true because depending on the conditions in dissolving the metal you will MOST LIKELY end up dissolving all of the metal with left over "free acid" - or not dissolving all the metal & needing to add more acid --- both of which means you are WASTING acid --- so those numbers are a rule of thumb of "about" how much acid it takes - not an absolute law of the acid required

As a rule of thumb it takes ABOUT 1 gallon of 67 - 70% nitric to dissolve ABOUT 8 pounds of silver - BUT - 1 gallon of nitric will only dissolve ABOUT 2 pounds of copper --- so it takes ABOUT 4 times more nitric to dissolve copper then to dissolve silver

Or ABOUT 1 ml 67 - 70% nitric per gram silver - or ABOUT 4 ml nitric per gram copper

If you control the conditions that you dissolve your metal under you can almost always - if not always use "less" (even much less) acid then the numbers I just gave you

So that you do not go wasting acid you will be best served by using about 70% of the above numbers when you first add your acid to the metal you want to dissolve (in other words - with silver - start out with about .7 ml nitric per gram silver) you can always add more nitric - if need be)

I have posted about this "many" times before

here are "some" links that will better explain the "conditions" & if you follow what I have posted about "conditions" you will ultimately end up saving yourself a lot of acid thereby cutting your cost & making more money - read everything I have posted in these threads & as will read any link provided in those post 









Dissolving the Copper in Sterling (nitric Qty?)


I'm trying to determine how much nitric I need. I've read that about 2ml will dissolve 1gr of silver. But how much more to account for the copper? For example, if I had enough sterling to yield 10ozt silver, I'd also have about 1ozt copper. According to my calculations I'd need about 660ml to...




goldrefiningforum.com













First attempt at silver refining


After drying it sat in my toaster over for couple of hours heres the weight dry. For batch 3 Its hard to make out but its 624.9, the weight of the empty vessal weighs in at 306.59 grams leaving me with 318.31 grams yeild. I started with 347.11 of clean sterling. Giving me a recovery of 91.7...




goldrefiningforum.com





Kurt


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## ssharktu17 (Dec 13, 2021)

kurtak said:


> Concerning - "how much acid (nitric) it takes to dissolve a given amount of metal (silver)" - there needs to be some clarification made here
> 
> When dissolving metal with acid (nitric in particular) there is NO SUCH THING as "it takes" or "you need" or "required"
> 
> ...


Yes I agree it would never be exact. I guess for this question though I am attempting to come up with a good average for cost analysis. So far, with the cheapest nitric acid I have found being about $200 for 10L, I am looking at about $1 per ounce to refine sterling assuming about 50ml per ozt of sterling. Thats nearly a 5% cut off the margin plus time required so its not that great and then finding a buyer will also be another issue.


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## orvi (Dec 13, 2021)

kurtak said:


> Concerning - "how much acid (nitric) it takes to dissolve a given amount of metal (silver)" - there needs to be some clarification made here
> 
> When dissolving metal with acid (nitric in particular) there is NO SUCH THING as "it takes" or "you need" or "required"
> 
> ...


I didn´t meant to post a universal number, maybe it was misunderstood. I wanted to correct the first assumption:


ssharktu17 said:


> Ok maybe I am missing something but most searches are saying 150ml nitric to dissolve one ounce of sterling? Even 10liters at $150 ($200 after taxes +shipping) is almost $3 per ounce to dissolve??


The issue from start was financial analysis, if that expensive nitric (50 USD/liter) could be used to make some profit with refining silver. I was pointing out many times, that the reaction and numbers are idealized to the corresponding equation to give estimated consumption of nitric per ozt. sterling, as there are other options of refining if the nitric cost will be to high. I just wanted to show that it is easy to estimate your consumption of acid, to know roughly how much you will need for your batch.


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## ssharktu17 (Dec 13, 2021)

orvi said:


> I didn´t meant to post a universal number, maybe it was misunderstood. I wanted to correct the first assumption:
> 
> The issue from start was financial analysis, if that expensive nitric (50 USD/liter) could be used to make some profit with refining silver. I was pointing out many times, that the reaction and numbers are idealized to the corresponding equation to give estimated consumption of nitric per ozt. sterling, as there are other options of refining if the nitric cost will be to high. I just wanted to show that it is easy to estimate your consumption of acid, to know roughly how much you will need for your batch.


I still have trouble justifying refining sterling. It seems like the only reason to do it would be if you are actually starting a full retail business to sell bars at a premium to customers. Even still I don't know how these guys make a profit. Bars usually only go about 10% over spot at best. So if you can get 90% melt value from a refiner then that is going to be a lot of work for just an extra 10% or less of profit after expenses. Especially considering some sterling may even get melt value. Seems like the only reason to refine it would be to make small high premium rounds. Maybe I am missing something.


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## Elemental (Dec 13, 2021)

orvi said:


> lucky you  10 liters for 150... very good price. i once thought about getting license, but this would be dive into the pile of s*it here.
> for liter, it is like 2,50+-, but tech grade 50% stuff in bulk (1000 L) is going below 60 cents.
> my whole refining is impaired by this restriction. practically speaking, only HCl is sold restriction-free for public here. luckily, i have access to some more "exotic" chemicals, mostly old stuff... to substitute the nitric. hence my experience with making it  that was like 5 years ago, i have done it the last time.
> 
> Edit: bad maths, i missed one zero :/ anyway, if i could get it for 15/liter, i would go all in





ssharktu17 said:


> I still have trouble justifying refining sterling. It seems like the only reason to do it would be if you are actually starting a full retail business to sell bars at a premium to customers. Even still I don't know how these guys make a profit. Bars usually only go about 10% over spot at best. So if you can get 90% melt value from a refiner then that is going to be a lot of work for just an extra 10% or less of profit after expenses. Especially considering some sterling may even get melt value. Seems like the only reason to refine it would be to make small high premium rounds. Maybe I am missing something.


For me sterling silver refining is a primer for gold refining. Gold refining is a big investment. The small amount of gold jewelry scrap I’ve been able to find is expensive for someone looking to make this a hobby. Silver also allows me to practice my wet chemistry skills which were pretty rusty.


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## ssharktu17 (Dec 13, 2021)

Elemental said:


> For me sterling silver refining is a primer for gold refining. Gold refining is a big investment. The small amount of gold jewelry scrap I’ve been able to find is expensive for someone looking to make this a hobby. Silver also allows me to practice my wet chemistry skills which were pretty rusty.


that makes sense good practice. I don’t deal with gold at all just sterling. If I find some gold I usually just sell it for melt pretty quickly on marketplace. I find a lot more sterling though.


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## timsiggins (Dec 13, 2021)

So this is the best deal I have found it is Nitric Acid, 4 x 2.5L [na10l] | DudaDiesel Biodiesel Supplies and 4 gals for 145 +shipping


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## ssharktu17 (Dec 13, 2021)

timsiggins said:


> So this is the best deal I have found it is Nitric Acid, 4 x 2.5L [na10l] | DudaDiesel Biodiesel Supplies and 4 gals for 145 +shipping


Yup that is the cheapest but shipping and taxes adds almost $50 for me.


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## Elemental (Dec 13, 2021)

Another option (I tried this unsuccessfully), is to contact your local university Chem Store. I tried this with University of Virginia and they said they would only sell to students, but their rates were really good. (Nitric Acid, Reagent Grade, 2.5L $ 29.66) Now that my wife is a grad student there, I might have her try to buy me some, along with some other lab supplies. It may be worth contacting one of the Chemistry Professors or the Chem Store direct and let them know you are a hobby chemist/refiner.

Elemental


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## ssharktu17 (Dec 13, 2021)

Elemental said:


> Another option (I tried this unsuccessfully), is to contact your local university Chem Store. I tried this with University of Virginia and they said they would only sell to students, but their rates were really good.  (Nitric Acid, Reagent Grade, 2.5L $ 29.66) Now that my wife is a grad student there, I might have her try to buy me some, along with some other lab supplies. It may be worth contacting one of the Chemistry Professors or the Chem Store direct and let them know you are a hobby chemist/refiner.
> 
> Elemental


This is probably the only way to make it viable. Contact refiners and chem departments locally. Good idea I wouldn’t have thought about universities.


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## Ray Levi (Dec 14, 2021)

Leoesch said:


> This is a link to the least expensive Nitric Acid you can buy. It's on Ebay and there is no hazardous surcharge.
> 
> 
> 
> ...


This is even cheaper. 1.57 gallons for $139.








JSP® Nitric(HNO3)Acid 6 liter (1.57 gallons)Gold & Silver Refining (gt544x6) | eBay


6 x 1 LITER (33.8oz) = 1.57 gallons Concentrated Nitric Acid HNO3 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.



www.ebay.com


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## ssharktu17 (Dec 14, 2021)

Leoesch said:


> This is even cheaper. 1.57 gallons for $139.
> 
> 
> 
> ...


That is still a lot higher than the other ones listed here.


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## orvi (Dec 14, 2021)

ssharktu17 said:


> that makes sense good practice. I don’t deal with gold at all just sterling. If I find some gold I usually just sell it for melt pretty quickly on marketplace. I find a lot more sterling though.


Where I am, the market is tight as hell, silver and gold. People here mostly know what they have, and they arent realistic about selling price. They try to sell the jewelery for more than gold value most of the times  pawn shops generally control the market with used jewelery, and are mayor buyers here. Deals with jewelers here are something like taboo  but maybe I was unlucky. I tried about 7 in two towns, get rejected with any kind of offer (even very very good %tage for sweeps), stopped to try anymore.
Sad that something like "garage sales" is not really a tradition here, so people like me can´t find some good deals on sterling that easy.
So my input doesn´t come from jewelery, just scrap. I would be happy if I could buy and process some jewelery, goes faster and cleaner than soldered pins in AR (which is my usual deal)


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## ssharktu17 (Dec 14, 2021)

orvi said:


> Where I am, the market is tight as hell, silver and gold. People here mostly know what they have, and they arent realistic about selling price. They try to sell the jewelery for more than gold value most of the times  pawn shops generally control the market with used jewelery, and are mayor buyers here. Deals with jewelers here are something like taboo  but maybe I was unlucky. I tried about 7 in two towns, get rejected with any kind of offer (even very very good %tage for sweeps), stopped to try anymore.
> Sad that something like "garage sales" is not really a tradition here, so people like me can´t find some good deals on sterling that easy.
> So my input doesn´t come from jewelery, just scrap. I would be happy if I could buy and process some jewelery, goes faster and cleaner than soldered pins in AR (which is my usual deal)


Ya I am lucky here in the US there is a lot of sterling that gets sold as just silverware or dishes. Garage sales are key. Not gold though I rarely find any that is even below melt.


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## voidforged (Dec 14, 2021)

ssharktu17 said:


> That is still a lot higher than the other ones listed here.


I have a sneaking suspicion that he's advertising his own eBay listings.


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## Yggdrasil (Dec 14, 2021)

voidforged said:


> I have a sneaking suspicion that he's advertising his own eBay listings.


And his own solution for dissolving and precipitating gold.
In another post.


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## galenrog (Dec 14, 2021)

I would not be concerned about Leoesch. I foresee the BANHAMMER soon making an appearance on his behalf.

Time for more coffee.


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## pawnshop (Dec 15, 2021)

orvi said:


> I didn´t meant to post a universal number, maybe it was misunderstood. I wanted to correct the first assumption:
> 
> The issue from start was financial analysis, if that expensive nitric (50 USD/liter) could be used to make some profit with refining silver. I was pointing out many times, that the reaction and numbers are idealized to the corresponding equation to give estimated consumption of nitric per ozt. sterling, as there are other options of refining if the nitric cost will be to high. I just wanted to show that it is easy to estimate your consumption of acid, to know roughly how much you will need for your batch.


It is not economical to refine silver in just nitric acid. For one, you will not get 99.9 pure silver from the silver cement. It is nearly impossible. The best way to refine sterling is with an electrolytic silver cell. This way the nitric goes much further and the silver is pure until such a point as the electrolyte (10% nitric acid) is oversaturated with copper. 

To get a better price on nitric you have to buy it 15 gallons at a time in a stainless drum. The drum deposit is $800- $900.


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## silver1 (Jan 24, 2022)

Get a business license and buy commercial!
Current commercial pricing.
69% nitric acid in 2016 was .38 cents/lb
69% nitric acid this time last year Sept 2020 was .44 cents/lb
69% nitric acid Jan 2021 was .55 cents/lb
69% nitric acid June 2021 was .60 lb
69% nitric acid as of Oct 2021 will be .67 lb
Hcl 31.45% is at .60 lb and climbing like the rest. This time last year it was .48 lb
Sodium Hydroxide beads have almost doubled to .70 lbs and that's if you can even get them. They are limited in supply and take 2 weeks notice and limited to 500 lb ration. I can't even order Magnesium Hydroxide right now and they don't know when they will have it in stock. Then they tack on a $30 fuel surcharge and you have to add taxes!


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## Gwar (Feb 20, 2022)

My supplier is DUDA Diesel !


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## GarageScientist (Apr 28, 2022)

orvi said:


> I think it should be far less. If we talk about dissolving pure silver, idealized reaction would be:
> 
> Ag + 2 HNO3 ---> AgNO3 + NO2 + H2O
> 
> ...


 I have a medical oxygen concentrator I've rigged up to a little MAPP gas torch. Could I pipe in a low volume of nearly pure oxygen, anything less than, say 3 liters/minute to more efficiently use nitric acid, for extra mileage, or would it be a negligible benefit and/or dangerous?


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## Gwar (Apr 28, 2022)

I could be wrong, but it seems I pay .09 cents per Ml of HNO3..


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## Alondro (Apr 28, 2022)

orvi said:


> sweet


Acetone... you can perform lots of organic synthesis! lol 

I was really good in orgo in college. Got a 99% formation of sulfanilamide for our practical lab. We got to play with chlorosulfuric/chlorosulfonic acid. That was back when college was actually useful.


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## Alondro (Apr 28, 2022)

Elemental said:


> An interesting video, but a lot of extra work and a new waste stream is created (copper sulfate + sulfuric acid). I am curious as to what the concentration of his final nitric acid was before fractional distillation. My assumption is most of what he distilled was really water with <1M nitric acid left over. This appears to be hours worth of chemistry just to regain a little bit of nitric acid. Don't get me wrong, definitely useful for those of you in countries where purchasing nitric acid off the shelf is not permitted, but as it's been stated here before, time is also a cost, not to mention a new reagent (sulfuric acid), waste stream, distillation and fractional glassware, etc.
> 
> As an aside, when he displayed his glassware that was not clean (covered in fibers and the solution sticking to the side walls of the e-flask, a scale covered in filth, and a dirty bench, it did raise a red flag and show a lack of lab cleanliness. I would hate to rest my arm on his lab bench, not knowing what I might be getting on my lab coat. The chemistry all sounded pretty good though and he put a lot of work into this. Thanks for sharing @Hombressino
> 
> Elemental


You can displace the copper nitrate to IRON nitrate, recovering the copper and THEN heating to recover the nitric acid.

Iron(III) nitrate decomposes near the boiling point of water and gives off nitric acid vapor. The iron will turn into iron(III) oxide (Fe2O3) and drop out of solution (hematite). It's MUCH easier to do than with copper nitrate.

I don't know why he decided to use copper nitrate, honestly.


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## VK3NHL (Apr 29, 2022)

I guess I’m luck here ‘down-under’ I get my 70% HNO3 @ A$120 for a 20Litre drum.
Cheers
Tony


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