# RenoVare electrolytic cell



## jsargent (Mar 20, 2009)

Check this out: http://www.renovare.com/docs/RRII-4003-0.DewBroch.pdf

They're using a carbon felt mat as the PM collecting cathode instead of a two dimensional electrode. They claim this dramatically increases the loading capacity and solution stripping ability of the cell. Anyone know any more details on this particular system?


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## Palladium (Mar 20, 2009)

jsargent said:


> Check this out: http://www.renovare.com/docs/RRII-4003-0.DewBroch.pdf
> 
> They're using a carbon felt mat as the PM collecting cathode instead of a two dimensional electrode. They claim this dramatically increases the loading capacity and solution stripping ability of the cell. Anyone know any more details on this particular system?



Bucky Balls    

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


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## jsargent (Mar 20, 2009)

Palladium said:


> jsargent said:
> 
> 
> > Check this out: http://www.renovare.com/docs/RRII-4003-0.DewBroch.pdf
> ...


 Maybe so... but I think it's plain old carbon felt mat they're using as the cathode. They want $25,000 for a bench scale model. They can't seem to understand why this hasn't been more popular in the mining industry. :roll:


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## qst42know (Mar 20, 2009)

That seems like a very clever design. A electrical filter of sorts that doesn't rely on pore size but instead close proximity to the charge. By passing the solution through the cathode they grab near all targeted metal 8)


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## jsargent (Mar 20, 2009)

qst42know said:


> That seems like a very clever design. A electrical filter of sorts that doesn't rely on pore size but instead close proximity to the charge. By passing the solution through the cathode they grab near all targeted metal 8)



Yep it's brilliant. According to the rep I spoke with, it was invented in England many years back and since been bought by their company. Essentially the carbon contribtes enormous surface area and does what carbon usually does in adsorbing metals, but the process is amplified by the electron flow thru the electrolyte. Huge loading capacity and strips gold and other PM's down to the low ppm range, whereas regular activated carbon performs not nearly so well. The device also uses a semipermeable membrane to keep reactive molecules such as halogens, away from the anode where they would otherwise form reactive halides. 
I bet I can build one of these.


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## bobinpasask (Apr 2, 2009)

If you happen to be successful in creating one of these beasts, I'm sure someof us would be very onterested in how you made it, how much it costs and, of course, if it actually works. !!

Some of us don't know as much chemistry as many of the folks on this forum and therefore, are at a disadvantage. It seems like this "Renovare" offers us the simplest way to recover PM's once we get them into solution and then become "stuck".

I have followed this forum for several years just watching and this is my first post. I have tried the "other" Steve's method using AR and got as far as dissolving several batches of fingers and one of CPU's. 

Now I sit looking at a 5 gal bucket of solution scratching my head trying to figure out what went wrong and no idea whyI only recovered 10% of what everyone else is getting.

So, you can see that the Renovare seemed like a good idea. But waaaaaayyyyy too expensive. On top of all the other kudo's you guys have received, thanks for sharing 
.


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## Harold_V (Apr 3, 2009)

bobinpasask said:


> using AR and got as far as dissolving several batches of fingers and one of CPU's.
> 
> Now I sit looking at a 5 gal bucket of solution scratching my head trying to figure out what went wrong and no idea whyI only recovered 10% of what everyone else is getting.


I trust you meant AR, not AP. If that be the case, and you've been around as long as you claim, perhaps you've read at least one post from me in which I mention that processing base metals with AR is one of the dumbest things you, or anyone, can do. 

I don't mean to be rude, but it is very important that you, as well as all others, understand this message. Believe it or not, it is an attempt to help you. 

There are no advantages to processing all the base metal along with the values, and lots of negatives, one of which is the risk of losing some of the values because they are precipitated on any remaining un-dissolved base metals. It's all too easy to toss them out when that happens, particularly if you aren't aware that it _has_ happened. 

I also fail to see any advantage in precipitating gold from dirty solutions, which is always the case when you dissolve base metals with the values. It assures you won't achieve great quality. 

There are occasions where dissolving with AR may be a requirement. Pins and/or fingers are not one of them.

Harold


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## bobinpasask (Apr 3, 2009)

Harold, There's no question I have been around as long (and longer than I care to admit ) as I claim. Problem is, there are so many good posts that I can't keep up with them all. I just happen to have purchased a method from the other Steve (not Laser Steve) and attempted to follow his method to the nth degree. That method detailed the use AR, so I did. 

Sooooo, 2 things. 
1. I will have to retrace my steps and learn the AP method and I will research it before I try it. (any suggestions as to where to start ?) and
2. Can I go back on the batches that I tried and screwed up and possibly recover any of the gold that is tied up in them ? Or is that a straight loss on the learning curve ?

Mr. Spevak's method was to use the AR, then neutralize with Nitrogen fertilizer, then drop out the gold using SMB. I returned 2 gm. powder from 500 gm fingers...... which I thought was approx. 10% of suggested return.

I truly appreciate your comments, Harold. They are easy to take in the context of learning (and hopefully not ruining too many more batches). 

I have lots of experience with gravity separation of fine gold from cons. from hardrock mining. This is my first try at the chemistry side of things.


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## Harold_V (Apr 3, 2009)

bobinpasask said:


> Harold, There's no question I have been around as long (and longer than I care to admit ) as I claim. Problem is, there are so many good posts that I can't keep up with them all. I just happen to have purchased a method from the other Steve (not Laser Steve) and attempted to follow his method to the nth degree. That method detailed the use AR, so I did.


First, it should be stated that I am not down on the other Steve. He's a fine individual, and has done his best to disseminate instructions pertaining to refining, but (good) information is hard to come by unless one had the good fortune to discover Hoke's book, which I did. Then, of course, later came Ammen's book, which I have not read. I assume it, too, has good information that would benefit a novice refiner. 



> 1. I will have to retrace my steps and learn the AP method and I will research it before I try it. (any suggestions as to where to start ?)


Certainly you can't go wrong by following the links provided in Lazersteve's sig line. He is likely the authority on the subject. I have never experienced refining by any other means than nitric and aqua regia. I am not familiar in the least with the other methods, although they are closely related. 



> 2. Can I go back on the batches that I tried and screwed up and possibly recover any of the gold that is tied up in them ? Or is that a straight loss on the learning curve ?


It all depends on what you've done. It's pretty hard to lose values unless you toss some of the material. If what has happened is what I suspect, you likely eliminated the values in filtration. If that be the case, if you still have the filter, you still have the values. If you found some dark fine particles in your filter, perhaps even leaning towards a dark brown, that would pretty much indicate that is the case. 

If your values are still tied up in the solution, which will be very dirty, it should test positive with stannous chloride. If it does not, and did not after you precipitated the values, it's safe to assume that the solution is barren. Make certain by testing your stannous chloride with a standard gold solution, then test again. 



> Mr. Spevak's method was to use the AR, then neutralize with Nitrogen fertilizer, then drop out the gold using SMB.


All effective, to be sure, but it's always better to eliminate as much of the base material as is possible before attempting to dissolve the gold. That typically results in a much cleaner product, and also smaller volume of solutions. Volume may not be important in the small amounts in question, but when you have multiple ounces of gold to process, vessel size becomes a serious issue. 



> I returned 2 gm. powder from 500 gm fingers...... which I thought was approx. 10% of suggested return.


I wish I could comment, but I ran very little e scrap when I refined, and that was never controlled. I ran it because it came to me free. I refused e scrap from customers. As a result, I know nothing about projected yields of such material. 



> I truly appreciate your comments, Harold. They are easy to take in the context of learning (and hopefully not ruining too many more batches).


Thank you. I tend to speak to the point, and am occasionally not understood well. 

I spend way too much of my time trying to help others, not only on this forum, but on one for machining. I am spread very thin, so I try to get directly to the point and expect that I am dealing with rational human beings that understand that I am offering a service with no strings attached. Those with wisdom can benefit, while those with an attitude are likely to be left behind. 

How about a report when you've checked your materials? It would be nice to hear you found the missing gold. 

Harold


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## goldsilverpro (Apr 3, 2009)

Your yield was 2 grams per 500 grams of fingers. That figures out to be about $53 US per pound. That sounds about right to me for average fingers. Of course, that would depend on the source, whether they are single or double sided, and how you trimmed them. In 40 years, the best fingers I have ever seen ran about $200/pound, based on the present gold prices. Your expectation of $530/pound is way too high. I can't imagine where you got that info.


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## Palladium (Apr 5, 2009)

Interesting facts about Activated Carbon and Adsorption. 

Comparison of Particle Sizes 
1-inch ball 25.4 mm (millimeters) = 25,400 um or μm or “microns” (micro-meters) 
pollen 10 - 100 microns 
smallest item visible to naked eye 40 microns 
fog droplet 2 - 50 microns 
“dirt” 40+ microns 
silt and clay ½ - 20 microns 
pathogenic protozoan cysts 3 - 20 microns 
Cryptosporidium oocysts 3 - 7 microns 
Cyclospora cysts 8 - 10 microns 
Giardia cysts 8 - 12 microns 
Entamoeba cysts 12 - 20 microns 
red blood cells 7 ½ microns 
most bacteria and algae ½ - 5 microns 
“turbidity” 0.1 - 5 microns 
colloids 0.1 - 5 microns 
wavelengths of visible light 0.40 (blue) – 0.77 (red) microns = 400 (blue) – 770 (red) nm (nanometers) 
cigarette smoke 10 – 1000 nm 
viruses 10 – 250 nm 
protein molecules 2 – 50 nm 
individual atoms 0.05 – 0.25 nm 



Adsorption: Not to be confused with absorption (which is what a sponge does), adsorption is the attraction of tiny particles or dissolved molecules to a solid surface and holding them there by weak intermolecular forces. It is similar in concept to magnetism and the attraction due to static electricity, but much weaker. In theory, every atom in the universe has some degree of affinity for every other atom in the universe, just like gravity. But, just as gravity requires enormous masses like planets and stars to show its effects, adsorption requires extremely tiny distances to show its effects. In adsorption, the particle in question is randomly bounced around the solution by collisions with water molecules and other molecules in the water. (This is called Brownian motion. 

It is estimated that an atom or molecule in water is involved in a million-billiontrillion or 1027 collisions with other atoms or molecules every second. This is part of the definition of temperature.) Eventually, by chance, it will be bounced so close to the surface of a wall or another larger particle that there are very few water molecules separating it from the surface. When that happens, those few molecules produce only a few collisions from that side, and the particle is overwhelmed by collisions from the other sides and tends to become “plastered” to the surface by a continual barrage of collisions from the solution. This is the “physical” half of adsorption. The “chemical” half occurs if there is any chemical affinity between the particle and the material of the surface. If there is, the particle will become attached (adsorbed) and stay there; if not, it will bounce off right away or just diffuse away, later. 

The adsorptive forces (called van der Waals or London forces) are so weak that adsorbed substances can become desorbed rather easily—by adding certain acids, by heating the system, or by merely removing the contaminant from the influent water. For example, activated carbon filters or ion exchange beds nearing exhaustion are subject to desorption if the water quality suddenly changes for the better. That shows that these treatment techniques are equilibrium (balance) phenomena in which sorption and desorption both occur and achieve an average condition, like a well-matched tug-of-war. 

Since adsorption requires a surface, commercial adsorbent materials have very large surface areas and are exemplified by activated carbon, activated alumina, and fine powders such as baking soda. But many substances are so very insoluble or otherwise so readily adsorbable that even small surface areas can make a big difference. For example, most heavy metal ions (lead, mercury, copper, cadmium, silver, chromium) adsorb so strongly to the walls of both glass and plastic sample bottles that more than half of the total contamination can be missed in an analysis if the sample bottles are not treated with nitric acid first, to cause desorption. Similarly, many chlorinated hydrocarbons like the polychlorinated biphenyls (PCBs) adsorb so readily to both metal and plastic plumbing and filter materials that even coarse prefilters remove them very well. 

The adsorption and reduction of disinfectant chlorine by activated carbon is a special case. Activated carbon is a mild reducing agent and chlorine is a strong oxidizing agent, so after chlorine becomes adsorbed, it then actually reacts with the carbon. The chlorine is reduced to chloride ion (as in table salt and sea water), one atom of carbon is oxidized to carbon dioxide, and both are released to the solution (desorbed). Meanwhile, most of the spots on the activated carbon where all this took place become “auto-regenerated” back to their original, like new 
condition, ready to adsorb again. For free available chlorine (FAC), this 
takes only about fifteen minutes, which means that a small amount of carbon can achieve an acceptable steady-state condition if the flow rate is slow or intermittent. For “combined chlorine” (monochloramine), the reaction is much slower, and more carbon or more contact time is needed to achieve equivalent reductions. The chemical reactions between activated carbon’s “active sites” (C*) and these forms of chlorine are shown below. Note that any surface oxides on the carbon are recycled when reacted with monochloramine, while they are oxidized to CO2 and lost when reacted with free chlorine. 

Free Chlorine 
Cl2 + H2O ⇔ HOCl + H+ + Cl − (forming “aqueous chlorine”) 
C* + 2Cl2 + 2H2O ⇒ C*O2 + 4H+ + 4Cl− (the overall reaction) 
C* + HOCl ⇒ C*O + H+ + Cl− 
C*O + HOCl ⇒ C*O2 + H+ + Cl− 

Combined Chlorine: Monochloramine 
C* + NH2Cl + H2O ⇒ C*O + NH3 + H+ + Cl− 
C*O + 2NH2Cl ⇒ C* + N2 + H2O + 2H+ + 2Cl− 
Finally, most dissolved/suspended particles and molecules in drinking water that are highly adsorbable to something usually do become adsorbed to a larger particle before reaching the point of use. Thus, adsorbable contaminants can often be removed by mechanical fine-filtration because the contaminant in question is already adsorbed to a larger particle. If you remove the particle, you remove the adsorbed contaminants along with it. This commonly applies to heavy metal ions, many pesticides, other chlorinated hydrocarbons, viruses, and 
asbestos fibers. About Activated Carbon: Granular activated carbon (GAC) and powdered activated carbon (PAC) are the predominant adsorbents used in our industry. 

They can be made from nearly anything organic: coal, petroleum, wood, coconut shells, peach pits, ion exchange resin beads, fabrics, even waste plastics. The starting material is first charred—heated without air or oxygen, so it doesn’t burn up. Everything that can be vaporized or melted bubbles out as tar or pitch, leaving many holes and channels. Then the charred material is heated further, to above 1000陣C (hot enough to melt aluminum and lead), with the introduction of live steam or other activating chemicals. The superheated water vapor is extremely corrosive, etching more holes and extending channels to an amazing degree. Metallic impurities are preferentially attacked and washed out, resulting 
in a significant purification of the original material. 

However, the heat of activation does more than extend holes and channels and increase the surface area of carbon; it also changes the fundamental crystal form from amorphous “carbon black” to the perfect crystalline array of graphite plates. The carbon atoms in graphite are arranged in sheets or plates of interlocking six-atom rings that look like slices through a honeycomb. Such a perfect arrange-ment causes the London forces to focus and concentrate at the surface, making activated carbon the best (strongest and most general) adsorbent known. 
After activation, the carbon may be treated further to produce specific chemical qualities on the surface. For example, an acidic environment produces carbon with maximum capacity for heavy metals but minimal capacity for chlorinated organics, while an alkaline environment does the opposite. Most grades used in our industry are made for organic adsorption. When activation is complete, the carbon is a delicate, airy material that is so full of holes, it can barely hold together. It is crushed to a powder, and then proprietary binders are added to form granules of the desired size. The final product has a total internal and external surface area of more than 1000 square meters per gram, or half a 
football field inside a piece the size of a pea. 

Activated carbon adsorption is useful because the material has strong chemical affinities for several important classes of contaminants that are common in water. These are: 

1. Disinfectant chlorine: “Free available chlorine” (FAC) is readily 
adsorbed, then chemically reduced, and finally desorbed as chloride ion 
along with one molecule of carbon dioxide, with auto-regeneration of most 
of the carbon’s active sites and nearly infinite capacity. “Combined 
chlorine” (monochloramine) is less easily adsorbed, requiring more 
carbon or reduced flow rate for equivalent performance. 

2. Organic compounds containing chlorine and other halogens: Simple 
halogenated hydrocarbons are highly adsorbable to activated carbon. This 
includes a great many pesticides (DDT, Endrin, Lindane, Chlordane, etc.), 
industrial solvents (trichloroethylene, trichloroethane, tetrachloroethylene, 
carbon tetrachloride, etc.), and disinfection byproducts (THMs including 
chloroform, chloral hydrate, etc.). 

3. Organic compounds containing benzene rings: These include some of the most toxic chemicals, such as benzene, toluene, dioxins, polychlorinated biphenyls (PCBs), and phthalate esters (plasticizers for vinyls). 

4. Heavy metals: Lead, cadmium, and mercury adsorb readily, both as 
dissolved ions and colloidal oxide or carbonate particles, but the capacity 
is limited—similar to the capacity for THMs. 

5. Taste and Odor (T&O) compounds: The substances produced by 
microbes that are responsible for the common musty-earthy-mildewy T&O 
are extremely well adsorbed and with very great capacity 

http://www.everpure.com/pdf/shortcourse.pdf >>>>>>


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## qst42know (Apr 5, 2009)

The only thing you have to keep in mind is gold is elemental. You have not destroyed it only lost it. The trick is finding it and getting it back. It is as simple as that.


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## jsargent (Apr 7, 2009)

qst42know said:


> The only thing you have to keep in mind is gold is elemental. You have not destroyed it only lost it. The trick is finding it and getting it back. It is as simple as that.


 And sometimes it's as simple as unscrambling an egg.


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