Turn 999 gold to 9999 gold

[Argentum Auricle]

I can appreciate the effort for making your own nitric acid because of the expense in lower quantities that hobbyists use.

The benefit for Hydrochloric Acid escapes me because the amount of gaseous losses getting down to azeotrope concentration, unless of course you are trapping those gasses in a gas washing bottle. Plus, any impurities in the liquid are concentrated in the azeotrope strength acid, which is roughly half the volume of the 34% you can purchase.


As far as crystallization goes the, purity is only improved if you know beforehand what the impurities in the original product are. Otherwise you can easily bring down impurities with the recrystallization of the original salts.

This being said, the chemistry of it all is fun. Can you post a photo of your distillation apparatus?

It doesn't look like I have any pics of my full apparatus in action, but here is a picture of the end of a WFNA distilation with the gas capture flask removed and the heating mantle turned way up to melt the potasium pyrosulfate in the boiling flask - to make it easier to remove from the flask without having to wash out with water.

 

[Yggdrasil]

It doesn't look like I have any pics of my full apparatus in action, but here is a picture of the end of an HNO3 distilation with the gas capture flask removed and the heating mantle turned way up to melt the potasium pyrosulfate in the boiling flask - to make it easier to remove from the flask without having to wash out with water.

No picture in here

 

[Argentum Auricle]

This being said, the chemistry of it all is fun. Can you post a photo of your distillation apparatus?

Can't upload pics until i figure out how to re-size. GRF wont allow me to upload existing file size.

 

[Argentum Auricle]

No picture in here

Trying. Only pic i have is 108MP. How can I resize to upload? Usually sites give you the option to re-size instead of flat-out rejecting the file.

 

[Yggdrasil]

Trying. Only pic i have is 108MP. How can I resize to upload? Usually sites give you the option to re-size instead of flat-out rejecting the file.

Open it in your favorite picture app and save it in lower resolution as a jpg file or png file.
800 by 600 should be fine.

 

[Argentum Auricle]

Here it is! I had to text this photo to myself to reduce size. This was WFNA distillation - starting with 98% H2SO4 and 99.9% KNO3 (dry method).

 

[Argentum Auricle]

Here it is! I had to text this photo to myself to reduce size. This was WFNA distillation - starting with 98% H2SO4 and 99.9% HNO3 (dry method).

Basic set-up with no vigreux... only a spiral condensation column.

 

[Argentum Auricle]

I'll also add that I am so OCD, I even purify table salt to get the calcium silicate anti-caking agent out, before using for silver chloride!

 

[4metals]

As far as purifying my dry chemicals, It seems to me that many times, the suspected contaminants are insoluble - easily filtered out after the solute is dissolved. Then recrystallizing the salt after filtered. I am always concerned there are other salts contaminating my materials, which is why analysis is often part of my process. Via analyses, I am able to confirm the purity of my products, within 95% confidence.

I have no doubt that manufacturers making products like stump out seek out the cheapest lowest grade to make their product so it stands to reason that there will be impurities in their "pure" product. The stump will never know!

 

[4metals]

The HCl I buy is almost always contaminated. The last gallon bottle was so contaminated with iron it was a vibrant yellow color.

Usually the Hydrochloric Acid purchased for karat refining is tech grade called Muriatic Acid, and I've seen it past the point of being yellow all the way to green.

However, for the purpose we are discussing in this thread, karat gold can be refined to .999+ with green muriatic and tech grade nitric. I only use reagent grade for assays. But most karat refiners miss out on the Bill Nye science guy moment!

 

[4metals]

Here it is! I had to text this photo to myself to reduce size. This was WFNA distillation - starting with 98% H2SO4 and 99.9% KNO3 (dry method).

Before someone else kvetches at you, I see this setup is outdoors on your deck. Good for you.

 

[Argentum Auricle]

Before someone else kvetches at you, I see this setup is outdoors on your deck. Good for you.

I DIY'd my fume hood. Ive gone through 3 in-duct fans now, because I'm too cheap to buy a proper chemical exhaust fan. I'm still without a functioning fume hood as I dont want to spend $40 on another fan, so I've been working outside on my deck for the last 6 months or so, while using gas capture/fume scrubbers.

 

[Argentum Auricle]

However, for the purpose we are discussing in this thread, karat gold can be refined to .999+ with green muriatic and tech grade nitric.

Maybe its the perfectionist in me, but I dont like the idea of using contaminated reactants. There are so many ways to miss the .999/.9999 mark... using pure chemicals is one of the easier to control variables though.

Even so, using contaminated HCl may be okay for a 1st stage refine (in my humble opinion), but I would not want to use contaminated HCl in the last stage refining or to do a final wash/boil with my end .9999 fine product. It seems like it is another potential vector for contamination of the final product - especially if not rinsed properly. I'd rather eliminate that risk.

Then again... I'm an OCD hobbyist, and not an actual refiner working to efficiently refine high volumes.

For what it's worth.

 

[4metals]

Then again... I'm an OCD hobbyist, and not an actual refiner working to efficiently refine high volumes.

I have literally refined and set up refiners to process commercial sized lots to produce fine gold. But honestly it is the small producers and hobbyist refiners that have taught me the most. Guys like yourself who need to, or choose to, make their reagents and process smaller lots using atypical chemistry in small lots stretch the limits and teach us all the most. It is much easier to refine to high purity in larger lots than in 1 ounce lots.

So as strange as it may sound, thank you for all you and your ilk have taught me.

 

[Argentum Auricle]

I have literally refined and set up refiners to process commercial sized lots to produce fine gold. But honestly it is the small producers and hobbyist refiners that have taught me the most. Guys like yourself who need to, or choose to, make their reagents and process smaller lots using atypical chemistry in small lots stretch the limits and teach us all the most. It is much easier to refine to high purity in larger lots than in 1 ounce lots.

So as strange as it may sound, thank you for all you and your ilk have taught me.

You honor me. Thank-you!

I would be much less knowleagable without this forum. While I have a strong chemistry background from my time at University, I would not know anything in the realm of metallurgy, if not for the information I gleaned from all of you. I started refining in 2018, with 99% of my early knowledge coming from this forum and C.M. Hoke's book.

So... thank-you!