# Concerning Nitric..



## AuMINIMayhem (May 23, 2007)

Ok. I have a bunch of stuff coming that is "gold filled" of various karats. Everything from 12-18k. I don't fully understand how Nitric works (and I'm not sure this would be the correct placement for this post.. mods, please ove to the appropriate area if necessary..  )

When using Nitric, in theory, what is left at the bottom once all material is dissolved? According to lazersteve's tutorial, it is gold, however is it gold in it's original karat or does it refine it to a higher karat?.. IE: I put something that is "gold filled" 1-20 14k into some nitric after having cut it to expose the base metals. I give it overnight to do it's thing and come back the next morning to see some precipitates at the bottom of the dish. Am I looking at 14k precipitates or am I, in an ideal situation mind you, looking at refine gold possibly as high as 24k? I do know there are other steps to further refine the precips after a nitric bath, I'm just trying to figure out exactly how it works as I will within the next couple of weeks be attempting this for the first time.

Thanks guys,
Derek


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## goldsilverpro (May 23, 2007)

If the gold is 10K or less, hot nitric will dissolve the base metals and silver from the karat gold laminate plus the entire substrate (the core), leaving only gold powder undissolved.

Nitric won't attack any karat gold over 10K. It will dissolve only the core, leaving the karat layer intact. However, the nitric must find an opening in order to get at the core. You'll have to cut or break the pieces to expose the core to the nitric. The problem with cutting is that you pinch the cut ends together. If you're talking about that necklace, you've got your work cut out for yourself.

You might consider dissolving the whole thing in HCl plus sodium nitrate. Ask Catfish. He had good luck recently dissolving regular karat gold this way.


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## AuMINIMayhem (May 23, 2007)

GSp.. yeah, the necklace as well as some GF wire and other goodies.. hmm that actually might be easier.. so anything over 10k has to be inquarted before nitric would "refine" it.. ok, no it's starting to make sense..

I'll have to go back and read how catfish did that.. he had a really good yield form what I saw.. and the cool thing is, I have both of those ingredients at my disposal, now!..


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## goldsilverpro (May 23, 2007)

You don't have to add anything to it to inquart it. If you just melt and shot it, it will be automatically "inquarted" because of the core material. This would actually be the best way to go, if you only wanted to use nitric.


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## AuMINIMayhem (May 23, 2007)

yeah, that might be the best way for me at the moment.. besides that'll give me a chance to try you method of chruning the water with a prop-blade on a cement mixer... I have no idea why I have both, but I do.. should make some very tiny shot.. the smaller the better, correct?..


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## catfish (May 23, 2007)

Hi Mayhem:

You may want dissolve the filled or rolled gold in a solution of HLC and Sodium Nitrate or Nitrate Soda (same thing). I don’t think you need to worry about shooting it or or hitting it with nitric. I just finished 20 grams of 10 and 14 karat regular gold jewelry yesterday and today. I refine quite a bit of karat gold. I use the following:

8 oz of Nitrate Soda mixed with 480ml of very hot water and dissolve it.
960ml of HLC (32%) mixed with the nitrate soda and H2O solution. Stir the solution and let it set for about 5 minutes. Salt will form on the bottom of the container. I just pour off the clear solution. This amount of (sic) Aqua Rega will dissolve 140 grams of metal (plated or filled Material) or 48 grams of solid karat gold. 

I cut up the solid gold into small pieces and put them in the solution. Then take and place it on a hot plate and slowly bring it up to a boil and let boil until all action stops. should take about 15 to 20 minutes. Every thing should be dissolved. If for some reason some of the gold is not dissolved and is coated with silver chloride, then take that material and boil it in ammonia hydroxide and it will clean up to shiny gold again and put it in AR again until all is dissolved. I never use any Nitric acid or shot it. This has always worked for me and I can achieve excellent yield results out of my karat gold. I consistently yield 41% on 10 k and 58% on 14 karat. This is + or – 2% tolerance of Manufacturing standards.

After you totally dissolve the gold then I mix up 8 oz of urea in very hot water and neutralize the AR. You probably won’t need all the urea, but I always mix a certain amount incase all the nitric hasn’t been used up. If you get too much urea in the solution, no big problem for it is in liquid form, wont hurt anything. It’s better to have too much than not enough. Filter your solution good, I use a vacuum filter and then add 1 oz of SMB mixed with very hot water, and stir good. Let it set for a few hours if you are not in a hurry. Some folks heat it up to speed up the precipitation. When you get to be an old fart you stop being in a hurry. When you let the gold precipitation. Always test the spent solution for gold with test solution. Never, never leave the table with possible gold left.

Make sure you use a heat resistance container. I use Erlenmeyer Flasks and always a glass stirring rod.

If you would like some more info on this method, PM me and I can send you an excel sheet with all my formulas on all different amounts of plated, filled, rolled, karat gold and also CPU chips. Also how to test a pins for a educated guess on just how much you can expect from a plated item.

Catfish


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## lazersteve (May 23, 2007)

Catfish,

Sounds like you've got a very good system! :wink: I've been inquarting everything first. I've used the nitrate muriatic mix, but I didn't like the BFRC (Big Freakin Red Cloud!!!) floating around my neighborhood!! What do you do to contain the fumes? What do your neighbors and animals think of the BFRC? :lol: 

You should do a tutorial on this on. I for one am very interested in seeing it done.

Thanks for the awesome post!!

Steve


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## catfish (May 23, 2007)

Steve.

The only reason I boil the solution is to dissolve it in about 20 to 30 minutes. I do it outside and there isn’t too much fumes. I also sometime just put it in AR and let it set over night. Just normal AR fumes. Nothing bad. I use my wife’s hot house to do all the AR and dissolving. (No Plants).

My wife’s old lack lab doesn’t mind it at all. She has learned to stay away from my shop and activity. When she was a pup she ate all the wires on my bass boat trailer twice. I let her chew on an extension cord and guess what she doesn’t like to come around my shop any more.

She also doesn’t chew wires any more either. 

Catfish

PS if any one is interested in this spread sheet, just send me your email address and I will send it to you.


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## catfish (May 24, 2007)

Hey guys:

I want to reemphasize that all chemical processes that we use for recovery and refining gold is dangerous and that all safety precautions should always be taken when working with any chemicals.

The process that I have used and shared with some of you folks is very dangerous and one should wear a good quality air respirator at all times when performing this work. Please remember that I live in the country with lots of pine trees. I live in very middle of 60 acres and my nearest neighbor is about ¼ mile away. I also use my wife’s hot house to do all my chemical work, such as Aqua rega, crock pot with Hydrochloric and nitric acid dissolving and etc. 

One needs to assess each and every case when using dangerous chemicals and make absolutely sure that you use every safety precaution. Noxx’s little saying sez it very clear, “No gold is worth your safety”.

I am working on a small chemical vapor scrubber by using 2” PVC pipe, a small muffin fan, and a chemical respirator filter element, and all in series to vent the filtered fumes out side up in the air. The pipe will fit over a 1000ml Erlenmeyer flask. Will let you folks know when I get it going.

Be safe and good luck.

Catfish


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## AuMINIMayhem (May 24, 2007)

Cat, will this work without boiling, perhaps mild warming?.. my crockpot doesn't seem to get to boiling temps and I realllllly don't think it'd be a good idea to use the "old lady's" expensive pots on the stove.. if I wasn't dead from the fumes, she'd finish the job, if ya catch my drift.. :shock: :lol: :lol: 

BTW.. Steve, BFRC! Too Funny! I gotta remember that one.. :lol:


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## catfish (May 24, 2007)

Hi Mayhem:

Yes it will work very good cold. That is the way I normally do it on all pins and chips. I mainly do the karat gold this way so I can make it happen fast. I have also done lots of karat gold on a cold basis. Just let it set for 24 hours no heat at all. Just remember that in very cold weather you will get some solids like ice due to the nitric, but you can heat it and it will dissolve.

The only thing with karat gold, if for some reason you have some that don’t totally dissolve, you will have to boil it in ammonia hydroxide to get the silver chloride off it and redo the AR process on the gold. This could take two days or more for the dissolving process. You will find that karat gold will drop fast if you properly neutralize the solution. Like 30 minutes or so. Gold from pins and chips etc. doesn’t drop that fast, in fact I let mine set for 24 hours before I decant it off and start cleaning it up.

I use an old coffee pot or a very good heat resistance flask to do the cooking of the gold. I then use a good corning ware deep bowl to clean the gold by using Harold’s and Goldsilverpros methods.

Lots of luck

Catfish


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## AuMINIMayhem (May 24, 2007)

Ambient temps around here have been in the 80's-90's during the day and 60's at night, so ice shouldn't be a problem. And I'm not in a terrible hurry, I'd much rather take my time, be safe and be able to post pics of the whole process from start to finish.. it'd be really nice to be able to get a "Wooo Hooo! You did it!" for once.. :lol: 

Now, once I let the mixture set, I use Urea and then SMB as well?..(I'm just referring to your earlier post.) I did read somewhere else where Harold (I think) said sometimes it's good to use multiple precipitants incase the gold is locked up by other metals, etc.. is this why?... 

Now, concerning Urea.. where can I get that?.. is that another one of these you can oly get it at a chemical supply house type deals or can I find it at my local hardware/lawn and garden store.. is there a specific grade I need to be looking for? (same goes for Ammonium Hydroxide)..

I'll peek over to the Chemicals thread to see if I can find any answers.. but a link would be really helpful if you can find one.. 

Thanks again for all your help, I really hope to be able to make a contribution to the Gallery thread soon.. 

Derek


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## AuMINIMayhem (May 24, 2007)

Ambient temps around here have been in the 80's-90's during the day and 60's at night, so ice shouldn't be a problem. And I'm not in a terrible hurry, I'd much rather take my time, be safe and be able to post pics of the whole process from start to finish.. it'd be really nice to be able to get a "Wooo Hooo! You did it!" for once.. :lol: 

Now, once I let the mixture set, I use Urea and then SMB as well?..(I'm just referring to your earlier post.) I did read somewhere else where Harold (I think) said sometimes it's good to use multiple precipitants incase the gold is locked up by other metals, etc.. is this why?... 

Now, concerning Urea.. where can I get that?.. is that another one of these you can oly get it at a chemical supply house type deals or can I find it at my local hardware/lawn and garden store.. is there a specific grade I need to be looking for? (same goes for Ammonium Hydroxide)..

I'll peek over to the Chemicals thread to see if I can find any answers.. but a link would be really helpful if you can find one.. 

Thanks again for all your help, I really hope to be able to make a contribution to the Gallery thread soon.. 

Derek


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## AuMINIMayhem (May 24, 2007)

disregard the chemicals question.. found the link that answered my question for that part..  

http://au-prospecting.com/gr/gr.html

Have I told you what a great resource this site is?..


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## catfish (May 24, 2007)

Hey Mayhem:

You need to go to your local feed and fertilize store or garden center. They sell Nitrate Soda, same thing as Sodium Nitrate, 4 lbs for $6.25. This will be 16% Nitrogen. Manufacture is Hy-Yield and there are other brands too. All about the same price. This is much cheaper than sodium Nitrate and the same thing.

You can buy the Muriatic acid (Hydrochloric acid) called (concrete cleaner) from any builders supply, Lowes or Home Depot, just look in the Paint section. Be sure and ask for concrete cleaner or Muriatic acid, they will not know what Hydrochloric acid is. This will be 31 to 32% Hydrochloric acid. Costs about 4.20 per gallon

You can buy Urea from the same fertilizer stores or garden centers. Cost is $8.60 per fifty (50) lb bag. This will be about 39 to 40% nitrogen.

I buy my Sodium Metabisulfite from the chemistry store. There are many other places that sell it too. All about the same. In fact someone on the forum mentioned about having some for sale. The cost is not bad from The Chemistry Store, (10.50 for 3 lbs) but the shipping is a bitch. (12.50) UPS only

As far as different kinds of precipitants, Harold has recommended different precipitants for different chemicals. I only use the SMB. I always test the solution with precious metal detection solution to make damn sure there is no gold left. Good commercial test solution will last about 6 months and test as low as 4 parts per million. The home made solution will only last about a week and may not consistently test as low as commercial test solution. So far I have never encountered a situation where I needed another precipitant yet, but you must remember, Harold and Cris has been doing this a long time and both are considered professionals in my opinion in this field. I am just a neophyte. You may want to pm them and ask their advice or recommendations.

When you get all your stuff lined up, hit me on PM and I will walk you through the first batch, it if you want.

8 oz of Nitrate soda .50
32 oz of hydrochloric 1.05
8 oz of Urea .09
1 oz of SMB .48
Total per batch 140 grams	____
of pins or 48 grams of karat	$2.12 
or about $7.00 per pound of pins.
gold.

If you should get some urea that has trash in it, no problem, just let me know and I will tell you how to handle it.

Lots of luck Catfish


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## Harold_V (May 24, 2007)

AuMINIMayhem said:


> I did read somewhere else where Harold (I think) said sometimes it's good to use multiple precipitants incase the gold is locked up by other metals, etc.. is this why?...



The purpose for using a different precipitant is to minimize contamination from something that persists in following the gold. Use only one precipitant per refining-----multiple precipitants would be a waste of time. An example would be to precipitate with ferrous sulfate the first refining, then perhaps sulfur dioxide for the second refining. 

I've rarely found it necessary-but I also refined by different methods than I'm reading here-----I did my level best to eliminate base metals in all instances, before dissolving the gold. The cleaner your gold chloride solution, the cleaner will be the gold that is precipitated. From that you can conclude that you'll have far better luck with gold filled if you first dissolve everything with nitric acid----without melting anything. All that does is make it hard to collect the remaining gold, and does very little to promote cleaner gold. The gold layer is so thin that it will leach the silver and base metals from the gold that is left behind---and you'll not carry them through to the gold chloride. Heating the acid is always best. 

Harold


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## AuMINIMayhem (May 24, 2007)

Awesome, Thanks HV!  I knew I had read a reason for that.. (see, I pay attention..  )


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## AuMINIMayhem (May 24, 2007)

catfish said:


> 8 oz of Nitrate soda .50
> 32 oz of hydrochloric 1.05
> 1 oz of SMB .48



These items I have.. I got the SMB from a "home winemaking" place here in town.. The HCL I'm very familiar with, we used it to clean grout off our hands and tools when I used to do tile with my Dad and Grandfather growing up, so that's covered (and I'm familiar with how it reacts with air/water and fume abatement, etc.. check!) the Nitrate of Soda I picked up at a local store a couple of weeks ago when I was making a poor attempt at a homemade smelting flux.. damn near melted my kiln down (there's pictures on here in one of the threads..) I got a pretty good deal on that cause the place was closing and all their stuff was 50%.. so far, I'm doing pretty good.. yay! 

So really I guess I just have to find the Urea.. should I go looking for the Ammonium Hydroxide while I'm at it?..(from what I'm reading on google, that's the same thing as just plain Ammonia, am I correct?..).. mixing Ammonia, Nitrate and an Acid.. what are the chances of me accidentally making a bit of a boom? :shock: :shock: (not just for me, but a safety concern that perhaps ought to be addressed for anyone reading this..)

Thanks for all the help, again, I'll post pics, stories and experiences as they happen.. I'll be working on it this w/e so wish me lots o luck.. 

Cat.. when I get the rest of the stuff, I'll pm you and let you know.. Thanks!


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## catfish (May 24, 2007)

Mayhem;

Sounds like you are just about ready to go. Ammonia hydroxide is just plain ammonia cleaning solution (sometimes referred to as aqua ammonia) you can buy at any Dollar general store, or your favorite grocery store. About a dollar a gallon.

Listen, if you don't feel comfortable in doing this, don't. The only safety hazzard I am aware of is the fumes that the Nitrate sodia and hydrochloric AR gives off while disolving all the metals. Once you neutralize the spent AR it is very inert. Once you precipitate your gold, then place the spent solution in a five gallon bucket and add slowly baking soda to it and neutralize, or the ashes from your fire place. Once totally neutralized, it is just dark solution, like dirty water. Very safe. Most folks I know then pour it down the drain, but you may want to check your laws inregards to disposal.

catfish

PS I buy baking soda at the pool supply store, much cheaper and in 50 lb bags.


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## Palladium (May 5, 2008)

8)


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