Electrochemistry Valid Refineit nitric cell alternative?

[Debbi Brys]

Could I use a regular coffee filter as the anode filter bag in a nitric cell?
Or would a paper coffee filter will fall apart in hot nitric after 12- 24 hours, and tear as I remove it with my gold?
Why is ashless filter paper recommended?
Deb

 

[Debbi Brys]

Come on guys you can do better than that!
Avoiding my questions and passing the buck?
That isnot going to fly with me.
Could I use a regular coffee filter as the gold alloy anode filter bag in a nitric cell?
Would a regular paper coffee filter will fall apart in hot nitric after 12- 24 hours?
Why is ashless filter paper recommended?
What is the micron rating of the filter paper required?
Anyone know ?
Deb

 

[Gold]

Now why on earth would you post a question wait 10 mins and then chastise people for not answering you by demanding an answer almost immediately. Do you feel that is motivation for someone to answer you? Then you want someone to freely share knowledge with you, but yet you demand it almost as if you are entitled to it just for the sake of asking. The answers to what you are asking are here i can guarantee it! Don't get frustrated, search!

 

[solar_plasma]

@gold
He or she has asked that before in this thread.

@deb
There are many possibities why a question not gets answered. Sometimes it shows too clearly, that someone hasn't searched enough and the answer is already given some hundred times by those, who know the answer. If this is not the case, maybe nobody feels sure enough to answer it with proof facts. The only people here who are in the position to tell what "flies" and what not, are the moderators and noxx and maybe some of the most merited veterans. If you want to get many answers in future, it might be a good idea to get very polite and modest in the next words you are posting. I don't want to offend you, it is only a well meaned advice.

 

[rickbb]

@deb, people are not here all day every day. Most of us just check in once a day if that much. Not a place for instant answers.

 

[NobleMetalWorks]

Come on guys you can do better than that!
Avoiding my questions and passing the buck?
That isnot going to fly with me.
Could I use a regular coffee filter as the gold alloy anode filter bag in a nitric cell?
Would a regular paper coffee filter will fall apart in hot nitric after 12- 24 hours?
Why is ashless filter paper recommended?
What is the micron rating of the filter paper required?
Anyone know ?
Deb

I have to admit that I'm a little shocked by the way you are demanding.

All the information you seek in here, in the forum. All you need to do is search for it.

Also you can use google and use terms like "what is ashless filter paper"

If you use paper in Nitric Acid, you run a chance of creating Nitrocellulose

http://en.wikipedia.org/wiki/Nitrocellulose

I gave you an example of what you should use, they are used for exactly the purpose you are asking about, if you choose to ignore it I am not sure what else to tell you.

If you are asking for information so that you can build a system of your own, you might want to search the forum as well for examples of those types of solutions and what other people have done before you. If you are looking for information so you can build, and sell these types of units then you really should learn a bit more about the process, which in turn would answer your questions, before you attempt to do so.

As I am posting this, I am also working, refining my own material, matter of fact I only have a few days to do so because I have to be somewhere to help a family member. I would venture to say that most people who have the type of information you are hoping to find here, are also working, that's why they have this information because this is the type of work they do. If you do not get an answer right away, it's probably because there is nobody available with free time to answer you back.

I can tell you this, and you can search for it in the forum so you understand what I mean. People who have a sense of entitlement are offensive. It's been talked about more than a little bit.

Also you might want to remember that the time that people take to answer you, is time out of their life that they are devoting to answering your questions. They are not paid, they are not rewarded for doing so, and in many cases they are imparting hard won knowledge that may have taken them years to accumulate. People who do not attempt to help themselves before they ask questions are also talked about on this forum.

And finally, what really concerns me is that you are seeking information it seems, to build your own system, but have not yet learned enough to understand how the process works, that nitric acid alone does not dissolve gold, and if coffee filters can or should be used. If you are truly attempting this on any level, you should already have learned enough to know these things. My suggestion to you would be to stop, stop thinking about operating a piece of equipment like this, stop asking questions you should be learning during the process of learning about refining. Pick up C. M. Hoke, Refining Precious Metal Waste, it's on this forum in electronic format and will give you a good start.

As far as I am concerned, I am done attempting to answer your questions, or helping you, until such a time as you show that you are trying to help yourself. It's not the responsibility of people on this forum to answer your questions, and certainly not at your beck and call.

Scott

Edited:

I wanted to say thank you to Debbi Brys for sending me a PM and being so nice. I understand much better now, and probably was a little harsh in my response, if I was I apologize.

Scott

 

[Gold]

You should be able to use a double layer of Muslin cloth. It's cheap, economical, and efficient. You can find it online or at Wal-Mart.

 

[Geo]

some people use vacuum cleaner bags. cut out the shape you need. i believe most bags trap particles as small as 1 micron (a coffee filter is 5 microns).

 

[Debbi Brys]

I am currently reading Hoke, Seems that the average beginner backyard gold refiner has many choices of refining technique. Chemicals, electrolyte process, etc.

 

[g_axelsson]

Come on guys you can do better than that!
Avoiding my questions and passing the buck?
That isnot going to fly with me.

Hi Debby,

maybe no one is answering your question as you are asking the wrong ones. I haven't heard of anyone on the forum that actually uses a nitric cell for recovering gold from pins. I can't find any reason to why anyone would like to do that.

I'm no expert on electrolytic cells but I've been interested in them for a long time.

A couple of years before GRF I tried to run a copper cell with sulfuric acid (aiming for removing the copper from gold plated pins) but it soon got depleted of copper. I then tried to add some copper nitrate and at that time I learned that acid and a salt creates the corresponding salt in the end. I could feel the smell of nitric acid. I don't know if it was just a reaction with the sulfuric acid in the electrolyte or a result from the electrolysis of a nitric salt. The result was that I finally had to shut down the cell in the end.

Based on my tiny bit of experience and what I have read about the subject I wonder if there wouldn't be a couple of big disadvantages with running a parting cell based on nitric chemistry compared to the classical sulphate cell?

- Nitric ions could be (is?) turned into nitric acid via electrolysis and can escape as gas.
- Nitric acid reacting with metals releases NOx gases and uses up the nitrates.
+ Sulphate ions that is turned into sulfuric acid which is absorbed and stays in the solution.
+ The only gases escaping from a sulphate cell is hydrogen and oxygen, easily replaced with some water.
- If you have too high voltage in a nitrate cell you can oxidize the gold into gold nitrate that is soluble and could be deposited on the cathode. (I don't know this but I would guess it could be that way)
+ If you have too high voltage in a sulphate cell any gold dissolved is precipitated back as a black powder as the gold sulphate is thermodynamic unstable.

This is only something pulled from my fallible brain so please comment.

Is there any reason to select nitric chemistry for a cell except a silver cell?

Göran

 

[NobleMetalWorks]

Based on my tiny bit of experience and what I have read about the subject I wonder if there wouldn't be a couple of big disadvantages with running a parting cell based on nitric chemistry compared to the classical sulphate cell?

- Nitric ions could be (is?) turned into nitric acid via electrolysis and can escape as gas.

You are using Nitric Acid as the electrolyte, I don't understand what you mean by "turned into nitric acid" it already is.

- Nitric acid reacting with metals releases NOx gases and uses up the nitrates.

The process does produce some toxic fumes, how much depends on the amount of silver for example, present in the gold alloy.

+ Sulphate ions that is turned into sulfuric acid which is absorbed and stays in the solution.

Are you talking about a sulfuric cell? Or are you talking about sulphate ions being present in a Nitric Acid Parting Cell? I don't understand, I will assume that the + means that it's a sulfuric cell you are talking about. In a Sulfuric "stripping" cell, simply stated, the sulfuric acid is transformed during the electrolytic process to persulfuric acid. Sulfuric acid does not dissolve gold alone, but persulfuric acid can. When the electrolysis is stopped, the persulfuric acid simply returns to sulfuric acid, and since sulfuric acid cannot hold gold in solution, the gold drops out of solution as a fine black sand. But you are not creating anymore sulfuric acid, it's just transitioning from one state to another.

+ The only gases escaping from a sulphate cell is hydrogen and oxygen, easily replaced with some water.

You do not want to add water to a sulfuric cell, you don't want to add water to sulfuric acid as it will spatter on contact, you never add water to acid but rather acid to water, You should be using as high a concentration of sulfuric acid as is possible, so if you loose any water, this actually would be a good thing. Matter of fact, you should cover or contain the sulfuric acid when not used because it will gain water if exposed to humidity and become less concentrated if exposed to air for too long a period of time.

- If you have too high voltage in a nitrate cell you can oxidize the gold into gold nitrate that is soluble and could be deposited on the cathode. (I don't know this but I would guess it could be that way)

Gold is one of the least reactive metals on the reactivity scale, it's not going to dissolve into the nitric acid electrolyte, thus it's not going to plate out. I think what you may be thinking about is the Wohlwill process, in where you start with chloroauric acid as the electrolyte and have a pure gold cathode to plate out on, and your alloyed gold you are intending to part as the anode.

+ If you have too high voltage in a sulphate cell any gold dissolved is precipitated back as a black powder as the gold sulphate is thermodynamic unstable.

You should not have too high a voltage, it's the correct voltage and amps applied in the correct way that turns the sulfuric acid into persulfuric acid which can dissolve gold. It doesn't precipitate gold as black powder, but rather cannot hold the gold once the persulfuric acid changes back to sulfuric acid, and thus is forced out of solution as a fine black sand/powder.

Is there any reason to select nitric chemistry for a cell except a silver cell?

Göran

There is a very good reason to use a nitric parting cell, as opposed to a sulfuric stripping cell, and vice/versa. Each recover gold from different types of material. A sulfuric stripping cell works with gold that is electroplated on another metal that is able to conduct electricity. But it shouldn't be used to part gold from other metals that are alloyed together. While a gold parting cell using nitric acid as an electrolyte is able to part alloyed gold, without having to upgrade or "inquart" the alloyed gold prior to processing. They are two totally different methods used for different types of material. Both have merits, and both have downsides just like with any process we use to refine any metals.

Scott

 

[g_axelsson]

Maybe I was a bit unclear, I tried to compare a copper parting cell based on nitric or sulphate chemistry.

I know the proper way to run both a sulfuric deplating cell, a silver cell or a copper parting cell and even a Wohlwill gold cell. I thought the discussion was about a nitrate salt based parting cell and I tried to make a case for the drawbacks by comparing it to a sulphate based parting cell.

I'm not going into details in all your comments as it's based on a misunderstanding of what I tried to say, but I just have one question. As you wrote...

There is a very good reason to use a nitric parting cell, as opposed to a sulfuric stripping cell, and vice/versa. Each recover gold from different types of material. A sulfuric stripping cell works with gold that is electroplated on another metal that is able to conduct electricity. But it shouldn't be used to part gold from other metals that are alloyed together. While a gold parting cell using nitric acid as an electrolyte is able to part alloyed gold, without having to upgrade or "inquart" the alloyed gold prior to processing. They are two totally different methods used for different types of material. Both have merits, and both have downsides just like with any process we use to refine any metals.

Scott

Could you please describe how a nitric parting cell works or give a reference to a posting about it. I have failed to find such a posting so far.
You wrote that

Gold is one of the least reactive metals on the reactivity scale, it's not going to dissolve into the nitric acid electrolyte, thus it's not going to plate out.

Wouldn't carat gold that isn't inquarted shield any alloyed metal unless the gold actually goes into solution? Either carat gold is shielding the base metals and you need inquartation to gain access or you dissolve the gold in some way. You can't have it both ways.

Göran

 

[NobleMetalWorks]

Could you please describe how a nitric parting cell works or give a reference to a posting about it. I have failed to find such a posting so far.

The current passing through nitric acid, acting as the electrolyte, causes oxidation of the silver and base metals in anode. The following ionic reaction then occurs:

AG--AG++e-

Cu--Cu+.sup.2 +2e-

Zn--Zn+.sup.2 +2e-

and so on, depending on the other metal alloys in your anode basket.

When these metal particles come into contact with the cathode, they immediately react with the nitric acid forming nitrate salts, Ag(NO.sub.3), Cu(NO.sub.3).sub.2, Zn(NO.sub.3).sub.2, which are readily soluble in the water present in the electrolyte.

Because gold has a high resistance to oxidation, it never dissolves into solution and thus is left behind in the anode basket filter as fine sand or what some people might call mud, or anode slime, etc.

This is just a basic explanation of what is going on, without giving details on voltage or amperage, the distance from anode to cathode, the percentages of nitric to distilled water and many other details that would be needed in order to build and operate a cell of this nature.

You wrote that

Gold is one of the least reactive metals on the reactivity scale, it's not going to dissolve into the nitric acid electrolyte, thus it's not going to plate out.

Wouldn't carat gold that isn't inquarted shield any alloyed metal unless the gold actually goes into solution? Either carat gold is shielding the base metals and you need inquartation to gain access or you dissolve the gold in some way. You can't have it both ways.

Göran

If I were using strictly a hydrometallurgical method to dissolve the metals into solution, such as Nitric Acid without using electrical current, I would have to upgrade the silver content or "inquart" so that the silver content was a high enough percentage that the gold was not able to protect it from being attacked by the Nitric Acid.

However, when you use Nitric Acid as an electrolyte, you are oxidizing the base metals, and then turning them to their salts at the cathode which are soluble in water. So to make simple what I am saying, instead of converting the base metals directly into their nitrate salt state, they are oxidized first, then change to their nitrate salt after contact with the cathod and soluble in water so dissolve into solution right away.

Sometimes, if too much voltage is applied to the anode, the gold can build up with the oxidized metals and create a shell that can protect for a short time the metal underneath, but as soon as the metal underneath is oxidized, it breaks the layer of oxidized metals on the outside, and the gold caught in the oxidized layer falls to the bottom of the anode basket.

I hope this clears things up a little.

Scott

 

[Geo]

you can inquart with copper but it would take 4 times as much nitric acid to inquart with copper rather than silver. the principle is the same but the economics tell us to use silver.

 

[Debbi Brys]

Thank you everyone so much for helping me, with my newbee questions. Are facts about the original Refineit Gold Refining System here in the forum? May I ask. Anyone actually have experience with it? Will someone please direct me to the correct area within this forum to look? I am not demanding answers. But I am still curious. I am still having a filter choice problem. Yes, muslin cloth and vacuum filter was recommended by a couple of you here. I am wondering if this material is ashless when burned along with the refined gold. And, from what I am learning. It makes sense, that the refined gold in the cell wont plate out on the cathode if the power supply is adjusted within a reasonable limit. Later, Deb

 

[Debbi Brys]

I am posting this in two different places. I hope I don't get into trouble. I am sorry if I just broke a rule. Thank you everyone so much for helping me, with my newbee questions. Are facts about the original Refineit Gold Refining System here in the forum? May I ask. Anyone actually have experience with it? Can anyone please direct me to the correct area within this forum to look? I am not demanding answers. I am still curious. I am still having a filter choice problem. Yes, muslin cloth and a vacuum filter bag was recommended by a couple of you. I am wondering if this material is ashless when burned along with the refined gold. And, from what I am learning. It makes sense, in a typical nitric cell, the refined gold in the cell wont plate out on the cathode. If the power supply is adjusted within a reasonable limit. Later, Deb

 

[jimdoc]

I am posting this in two different places. I hope I don't get into trouble. I am sorry if I just broke a rule. Thank you everyone so much for helping me, with my newbee questions. Are facts about the original Refineit Gold Refining System here in the forum? May I ask. Anyone actually have experience with it? Can anyone please direct me to the correct area within this forum to look? I am not demanding answers. I am still curious. I am still having a filter choice problem. Yes, muslin cloth and a vacuum filter bag was recommended by a couple of you. I am wondering if this material is ashless when burned along with the refined gold. And, from what I am learning. It makes sense, in a typical nitric cell, the refined gold in the cell wont plate out on the cathode. If the power supply is adjusted within a reasonable limit. Later, Deb

Yes this is a rule. This post will be deleted, so anybody wants to answer, find the other post.

Jim

 

[rickbb]

OK I was going to post in the other place but couldn't find it. :lol:

To get an ash less bag you'd have to buy one made for that purpose, muslin or a vac bag will not be ash less. But ash is not that hard to separate from gold using wash water or standard panning techniques.

 

[jimdoc]

http://goldrefiningforum.com/phpBB3/viewtopic.php?f=86&t=18822&p=190875#p190875

 

[rickbb]

To get an ash less bag you'd have to buy one made for that purpose, muslin or a vac bag will not be ash less. But ash is not that hard to separate from gold using wash water or standard panning techniques.