DeNOxing Gold Bearing Solutions: The Whys and Hows of it

In this video I discuss deNOxing of gold bearing aqua regia solutions. Why it may be necessary, and various to do it. I'm trying to clear up some confusion and misconceptions about the subject I am seeing in my emails and the comments of some of my videos. Please visit www.mdpub.com/UrbanGoldMining/... for more information.
Equipment used in these videos:
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Chemicals used in these videos
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[@IsettasRock]

Two methods I use exclusively depending on what material I have in AR Dirty solutions from gold recovery = add copper. This denoxxes and drops the gold with one step Clean gold refines = add more gold. This uses up the excess nitric and keeps the other weird salts out of the wastes

[@mikestewart4752]

Excellent explanation my man! As a relative noob to recovery/refining, I have always chosen small doses of nitric when refining gold. I figured that if the more experienced were touting it’s benefits, there must be something to it. Low and behold, it wasn’t hard to become proficient at the technique. A useful tip: I have found that diluting a small amount of nitric to 50/50 with distilled water after the bulk of your gold has gone into solution, allows you to accurately get the last of the crumbs without overshooting. Great video!

[@NOFX0890]

Lets all say it together now... incremental nitric dosing....✌

[@rockman531]

Fantastic video, Mike!! Your explanation was excellent! Thanks for taking the time to be our chemistry teacher. Take Care, Jim

[@stivers56]

Great informational video. That's what I like about most of your videos. You take the time to explain the procedures.

[@timdunk7278]

Hey, thank you so much for your clear and generous demonstration.

[@shaneyork300]

Those that are wondering about denoxing are probably at the beginning of there learning since that is a step that most people that do gold recovery do almost everytime they process. Great video and explanation!!

[@PHUCKyoutube689]

Those that learn incremental nitric dosing don't denox every time. In fact they rarely denox if ever.

[@shaneyork300]

@@PHUCKyoutube689 Yes, you are right, but when you are doing certain types all the time like ic chips ash it's hard not to put a little extra nitric in when getting the base metals & silver out. I guess I should've explained my comment better or just probably not left one at all. Thanks for pointing out what you did.

[@PHUCKyoutube689]

@@shaneyork300 That makes sense. My experience is in purifying placer gold. Haven't messed with the recycling yet.

[@shucksful]

Try guessing how much nitric you need for microscopic gold, in gold ore. 😂. Enjoying those boiling sessions, yet? Not me..I just picked up a container ofSulfamic acid crystals at Home Depot. The brand name is…”Aqua mix” Ten dollars well spent.

[@jeffholmes1362]

Good explanation, the only other way I know is to put a previously refined gold bead in until it stops desolving . Weigh the button before and after to see how much gold you’ve added then subtract that weight at the end if you care about recovery for that job.

[@NOFX0890]

The fact that iv never heard of this is a clear indication that i have not delved deeply enough into GRF as a resource. Thanks for sharing.

[@mrrongsoker8070]

Sulfuric acid complaining...🤭😂, Nice information dude..best video ,love it..👍

[@SilverStoll]

You have been so helpful with my new hobby. Wow is it cool. Thank you!

[@aussiescraphunter7808]

Thanks for a clear and concise explanation of the process and it's necessity, l knew it had to be done, l did not know why, now l do, once again thanks mate (fyi australian here)

[@macfixer01]

On the GRF, the preferred method some of the admins advocated was keeping around a previously-refined sacrificial gold bead, that they would put in at the end to use up any remaining nitric acid. They’d weigh the bead before and after each use, so they knew how much of it went into solution that session. Then they’d subtract that amount from the yield to get an accurate figure.

[@NOFX0890]

Very interesting, thanks...

[@TheEggman51]

Thanks for making this great video lesson. You have cleared up a bunch of unanswered questions for me. I've had the best results with the boiling down method as stated in the Hoke book. It is very time consuming and must be very closely watched. I will try sulfamic acid the way you've shown. Cheers!!!

[@weremouseworkshop8206]

Great information video thanks for sharing 👍

[@MrVeryCranky]

watched many videos on recovery of precious metals but don't recall this being explained before. Nice presentation, I'm not prepared for disposal of wastes from method one and reagents for method two are not generally available to Joe Public so I guess I'll be giving both proceedures a miss.😂

[@rottenlezaguilar8060]

Thanks for sharing your knowledge.

[@baja221]

Thank you! Very informative.

[@RandomActsOfRandom]

Beautiful and thank you.

[@rogerwalker8328]

And thank you for sharing!!

[@WaffleStaffel]

The energy required to detonate urea nitrate is similar to anfo, so there's no real risk of explosion. In fact, according to the Science Madness wiki, urea nitrate actually possesses fire retardant properties. It is a shitty de-noxer though, and as stated, the best thing to do is add nitric acid in small portions so you don't end up with an excess.

[@user-wm5zz2lc8t]

اشكرك علئ هذا التوضيح. كنت بحاجه اليه شكراا كثيراا ونتمنئ المزيد من الفديهوهات لتوضيح طرق الترسيب ص

[@OnsloVest]

Nice one

[@richardoconnor7162]

I use the boil down, or add more gold in a known amount to use it up. If I Denox I always then filter the solution because there might be dropped metal I want out of it be fore the drop of gold.

[@omegageek64]

I knew there was another method I was forgetting. I was going to mention the use of extra gold for deNOxing, but it totally slipped my mind.

[@knowldedge5012]

nice

[@MrRavipalsingh]

Excellent explained Sir, I have a query, is gold lost if we evaporate or gold evaporates if we denox by boiling

[@beverlybaehm8119]

Want to know what I did wrong put sulfamic acid in aqua Regis to neutralize to late in evening to finish. Next a.m. went to turn heat on to finish denox found sulfamic solidified in bottom still strong acid present.

[@richardhulbert9480]

So denox with urea mixed with sulfamic acid with a bit of sulfuric just to be safe. Thanks all clear now. Now your wearing blue gloves how can you tell left from right. I think I bought a whole box of left handed gloves

[@robertsletten7466]

I would tend to think if someone is deNOxxing with wrong acid because they misunderstood the difference... They should NOT be doing this at all or should study a LOT more ... before starting ... Or you'll at best make a mess ... or You may blow your self and your family up ... be careful people As always Thanks for making these videos PS. more information about what can and can't go in Stock Pot ... As well as nitric acid production w/a clean-up included.. Thanks again

[@lesliemorrison1305]

Do you have a video on the equipment that you use for the gold and silver recovery I can not find any place in my area that sells glass beakers or the glass stirring rod's so I was just wondering where you buy yours

[@omegageek64]

I don't have a video, but there are links to buy a lot of it at Amazon in the video description, since I get this question a lot.

[@cemilayarevi]

after adding sulfamic acid, there is no free nitric acid left .Because it turns into sulfuric acid.Can I get potassium gold chloride from here adding KCl

[@roberthainline4552]

I’m not going to use any more urea however if I do find this how do I dispose of it?

[@rogerwalker8328]

Question did you make the sulfamic solution with distilled water or hydracloric?

[@roberthainline4552]

What would set that explosion off does it need heat spark a flame just wanna know because I have been using urea and I don’t wanna have any problems

[@bully9917]

So, if i just add a very very small amount of spetricide stump remover (potassium nitrate) along with muratic (maybe 1/8th tsp), then do you think the resulting solution could be denoxed and precipitated all at once with bodide stump remove (smb), maybe 1/4th to 1/2 tsp mixed into solution with water ? I have heard SMB will denox to some degree, and wondering where that special spot was. I am recovering trace amounts of gold from very low grade rocks in a non-gold bearing region (ie. - gold exists, but not in commercial levels)

[@amrabdelmonen8569]

i used hcl and bleach to dissolve gold and tried to precipitate the gold using zinc and aluminum but it didn't work only naoh sodium hydroxide gave me an orange reddish precipitate but it looks like mucus in the beaker with removing the solution I heared that naoh is not preferred as it can dissolve some of the gold precipitate again but it is the only method that gave me that precipitate ...... is there a recommended method on how to use naoh or it is bad? why other methods didn't work ? I think I have added to much bleach . can you help me ,please?

[@bully9917]

second question sorry, Can you just let the solution sit in fresh air for a few days and allow the nitric acid to evaporate ? Will nitric evaporate first, or faster than the rest of the solution ?

[@user-tl7tz9lb9w]

Do you think the alcohol can do DeNOxing?

[@himmatbadal3696]

When I mix sulfamic acid the AR doesn’t turn colorless ... is there a way to make AR Colorless... I want to keep my gold in colorless AR as I live in a country of thieves

[@user-tl7tz9lb9w]

Very good information, but what if the AR were add SMB already before DeNOxing, how to make gold precipitation?

[@NOFX0890]

Keep adding SMB. Its a waste of material but it will cause minimal problems. A mildly expensive learning curve.

[@user-tl7tz9lb9w]

@@NOFX0890 Appreciate your reply, but I had once couldn't precipitate the gold by adding a lot of SMB till white crystal precipitated at bottom of beaker, I still don't know why until now, the gold I dissolved is about 0.2g only.

[@NOFX0890]

.2g throw it in your stockpot? Find another .2g to practice with. Id imagine it makes it more difficult chasing such a low yield. Maybe your concentration of solution complicated things. Good luck my friend youll get that .2g back eventually. If you can get those crystals to go back into solution, there is always copper.

[@reyhanaltunbas2683]

Merhaba yeni abonenizim harika videolariniz var severek izliyorum size nir soru sormak istiyorum üre yerine beyaz ispirtoyla nöturelize edenler var vede oluyor sizin bu konuda fikrinizi almak istiyorum bende deniyecegim cevap verirseniz çok sevinirim teşekurler

[@shaneyork300]

Question: This might sound like a strange question but, is the weight of gold different from the solid form and the liquid form?? I've seen videos of several ounces of gold in solution. Can the weight of the gold in solution weigh less than the gold recovered? I'm thinking of when the solution is boiled down, maybe too low.

[@omegageek64]

The weight of the solution will be the weight of the muriatic acid plus the nitric acid plus the dissolved gold minus the nitric acid that leaves the solution as nitrogen dioxide gas (orange-brown fumes). If you dissolve a lot of gold in a little aqua regia, you will have a very dense liquid indeed.

[@shaneyork300]

@@omegageek64 I don't mean the weight of any liquid just the gold in the liquid vs metal gold?

[@altinara9099]

🇹🇷🇹🇷🇹🇷👍👍👍👍❤️

[@j.brubaker2717]

sodium bicarbonate.