# AR



## p13t_chan (Jul 18, 2011)

Guys...I had try already for percipitated AR and i got the solution look like a jelly.any one ever happen like i did.


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## Harold_V (Jul 18, 2011)

What material did you process, and how? 

Did you eliminate base metals before dissolving the values?

From your description, I get the idea you included tin or aluminum. Both should be eliminated before dissolving gold. 

Harold


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## p13t_chan (Jul 18, 2011)

Yes i had eliminate mud use nitric acid then i neutrelized by urea then i used AR for dissolving gold for percipitate i used SMB but before that i was use HCl and Hot water.any wrong?


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## Harold_V (Jul 18, 2011)

What material did you process?

Harold


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## p13t_chan (Jul 18, 2011)

Materials is aluvial mud


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## Harold_V (Jul 19, 2011)

p13t_chan said:


> Materials is aluvial mud


Why do you suspect you have any values present? 
Processing mud (dirt) by acid is rarely successful. 

Harold


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## p13t_chan (Jul 19, 2011)

This mud had processed use carbon active and cyanide and they get the gold.So i had conviction this mud gold contain.
So i process used nitric and AR


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## Oz (Jul 19, 2011)

I hope you are being sure to destroy any traces of cyanide before you are adding acids!


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## Harold_V (Jul 19, 2011)

p13t_chan said:


> This mud had processed use carbon active and cyanide and they get the gold.So i had conviction this mud gold contain.
> So i process used nitric and AR


It would be very important that you had an assay on the mud before attempting to recover any values. It would be even more important that the cyanide that was used was killed, otherwise you risk exposure to hydrocyanic acid, which is known to be lethal. 

I expect that the material in question will be VERY low in gold content---most likely yielding virtually nothing for your efforts. Remember me telling you that ores (mud, in this case) are not usually successfully processed with acids? This one is like that---that's why cyanide was used. 

Did you test the resulting solution with stannous chloride? What did the test indicate?

Harold


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## p13t_chan (Jul 20, 2011)

Yes i did. and no react in cotton bud.i think it's very weird too.I think it's very small gold content.There is the most reasonable answer.Thanks harlord


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## p13t_chan (Jul 20, 2011)

Had you ever doing test from AR you neutralize with urea then AR would be back to be HCl.Isnt it?
my question is possilble if i processed gold with AR then i put urea in solution till to be HCl then i catch gold with electrochemistry use silver anode and silver cathode?What do think?cause platinum plate/rods is rare.


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## Harold_V (Jul 20, 2011)

p13t_chan said:


> Had you ever doing test from AR you neutralize with urea then AR would be back to be HCl.Isnt it?
> my question is possilble if i processed gold with AR then i put urea in solution till to be HCl then i catch gold with electrochemistry use silver anode and silver cathode?What do think?cause platinum plate/rods is rare.


You must pay attention to what you're being told. To attempt to recover gold that doesn't exist makes no sense. 

For starters, you mentioned that the material in question has already been processed with cyanide. It's used primarily on low grade ores, so even ores that haven't been processed are highly unlikely to respond to acid treatment. You can waste tens of gallons of acid on a sample of ore and get nothing, which is what I expect is happening to you. 

Forget about trying to recover values from ores that have already been treated. If cyanide is leaving gold behind, it won't be worth the effort unless those that are processing don't know what they're doing. 

The exception to what I'm telling you would be if you had an assay performed and it indicated that there was a considerable amount of gold present (several ounces per ton). I expect that is not going to be the case. 

Harold


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## p13t_chan (Jul 20, 2011)

> Harold_V said:
> 
> 
> > p13t_chan said:
> ...



No this is another test.I curious in theory AR made from 1 HNO3 : 3 HCl.the problem appear when the AR solution was dilute some gold then i put urea for neutralized and make it to be HCl.After that i put HCl (gold content) tp process electrolysis.
is it make sense??Cause in logic i think is make sense but if just try without basic i looked like dumb.


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## Harold_V (Jul 20, 2011)

I never attempted to extract gold electolytically, but a gold cell is known to work with a gold chloride solution, so, yes, it may work, but I expect that the gold will probably cement on the silver. I may be wrong----I never exposed anything to my gold chloride solutions aside from a proper precipitant--when I wanted to recover the gold. 
It might pay you to explore a Wohwill cell. That's the name of the cell that is used to electolytically refine high quality gold. Take note that the anode AND cathode are made of gold, not any other material, in an attempt to limit cementation. 

Harold


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## Geo (Jul 21, 2011)

sounds like you may need a good old fashioned gold pan. :lol: i had some friends that was processing soil that had what they called "flour gold".particles so small as not to be seen with the naked eye.what they did was to incinerate the soil with addition of a flux,twenty mule borax might work.you can do this in a sturdy cast iron pan.as the contents of the pan get to the stage of less than cherry red stir the soil with a piece of steel,if gold is present it will stick together and make larger pieces which will make it easier to work with.buy a gold pan and if you dont know how to pan for gold get a 10 gallon wash tub and a bag of play sand then get some small lead pellets from a shotgun shell #8 works great,flatten with a hammer.place ten pieces in a pan of sand and practice.when you can wash all the sand out and keep all ten pellets you should have no problem keeping your gold.then your AR should work just fine on the gold you find.


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## freechemist (Jul 26, 2011)

Hello p13_chan,

In your last post you stated:
_"No this is another test.I curious in theory AR made from 1 HNO3 : 3 HCl.the problem appear when the AR solution was dilute some gold then i put urea for neutralized and make it to be HCl.After that i put HCl (gold content) tp process electrolysis. is it make sense??Cause in logic i think is make sense *but if just try without basic i looked like dumb*."_

Having read through your's and Harold's posts, I must say, that your very last statement about trying without basics is perfectly true. Please, be patient before working further, and acquire the basics needed first. In this respect I agree entirelly with Harold's countless posts on reading.
I understand your curiousness and your need for practice, to consolidate the theoretical basics. Therefor a few hints for your further work from my own experience:
1.) A test-experiment never starts with unknown substances. It has to be carefully planned, using weighed amounts of material with most possible detailed known composition, such as pure gold, carat-gold, silver, other PM-alloys and so on. Only then you are able to choose appropriate chemical reagents and to calculate, measure and weigh their needed quantities.
2.) Working with AR in a wider sense means to work with mixtures of HCl and HNO3, using calculated excess quantities of HCl to generate chloro-complexes of the PM's involved and with the smallest possible quantities of HNO3 to oxidize PM's and possibly contained base metals in their alloys. An excess of HCl never becomes harmful, whereas a big excess of HNO3 can become really annoying.
3.) Never use urea to neutralize excessive HNO3. It won't do the job, and if working properly, it simply won't be necessary. It will stay together with it and HCl in solution, mostly unaltered, but hydrolyzing (reacting with water)more or less slowly, depending on temperature, forming CO2 (carbon dioxide) and ammonia, which immediately will neutralize every acid, forming ammonium salts like NH4Cl and NH4NO3. In industrial PM-refining urea probably can be used, to neutralize the reduction products of HNO3, namely gaseous NOx, formed in the dissolution process of PM-alloys in AR (and HNO3 only). At least, there exist some patents covering this subject.

@Harold: Gold, from a concentrated solution in acid and gold, like used in the Wohlwill-process, will indeed rapidly cement on silver, forming a thick porous cover of dark violet, nearly black colour, consisting of metallic gold and solid AgCl.


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## p13t_chan (Jul 27, 2011)

@freechemistry

I had tried for my experiment and everything was going like you said.
AR is not perfectly straggling when i put urea cause in chemical HNO3 cant perfectly straggling when they was mixed well.
Few days ago i processed 70grams alloy metal (density 10.8 g/cm3) and i get 1.06 grams gold and only 43 grams silver.my question is why losses many.Whereas i have tested alloy before,and composition are 2% Au,87% Ag and many more like Al,Zn,Cu in small scale.


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## dtectr (Jul 27, 2011)

i believe the density of gold is around 19.8g/cu. cm. The alloy you started with ...

EDIT: I stopped myself there - all of this discussion is getting away from the most important issue - There was no gold to recover. Hoke prescribed experiments with varying concentrations of gold in solution, quantified in advance, then tested with stannous chloride. The point of the experiment was to teach us that stannous chloride will detect even very minute concentrations of gold in solution. The application of this fact, as it applies to your situation, my friend, is that if no positive for gold was present when you tested (if it was performed properly) that for all intents and purposes, (as it applies to a profitable recovery of values), there is no gold in your materials.

Harold said: 


> For starters, you mentioned that the material in question has already been processed with cyanide. It's used primarily on low grade ores, so even ores that haven't been processed are highly unlikely to respond to acid treatment. You can waste tens of gallons of acid on a sample of ore and get nothing, which is what I expect is happening to you.
> 
> Forget about trying to recover values from ores that have already been treated. If cyanide is leaving gold behind, it won't be worth the effort unless those that are processing don't know what they're doing.



Cyanide has been used in the western United States, to leach gold from mines that were no longer profitable by any other method. The gold was likely micron in size. This occurred when gold cost $360.00 USD. As irresponsible as this sounds, a family friend worked for a company flooding workings with cyanide solution. 

My friend, if you want to begin to learn processes that do work on ores, or to begin to learn the refining process, I suggest that you begin another thread, in the appropriate section, with pertinent questions that follow accepted standards of practice. There has already been a massive amount of sound advice given on the original issue raised by this post.

An even better idea, would be to lay down your tools for now and begin reading. A good place to start is lazersteve's profile (go to "members", select "lazersteve", then view his "profile". It will contain links to pertinent information and accepted practices, such as the "Forum Rough Guide").

I'm sure you'll understand by now that _processing alloys_ and _processing ores_ require two entirely different approaches.

We wish you success, but we also wish you to be alive.

dtectr

EDIT: clarity


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## Harold_V (Jul 28, 2011)

freechemist said:


> @Harold: Gold, from a concentrated solution in acid and gold, like used in the Wohlwill-process, will indeed rapidly cement on silver, forming a thick porous cover of dark violet, nearly black colour, consisting of metallic gold and solid AgCl.


Thanks, kindly, for that response. It is one of the questions that always haunted me. So much so that when I built a Wohwill cell (which was never used), the racks were built of titanium to avoid the possibility of cementation on silver, as I'd read was the norm. 

Working as a refiner when you have the degree of ignorance I have is not always easy. 8) 

Harold


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## Palladium (Jul 28, 2011)

I was wondering about this same thing the other day, but in a different kind of way. I was thinking about shor's fizzer cell and how the anode was suspended from a silver wire. Then i thought once the power was off would the gold cement to the wire? I to also thought about titanium Harold. I guess that would hold true for all concentrations ? The more concentrated the faster the reaction ?


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## Harold_V (Jul 28, 2011)

So far as I know, titanium is inert, so it should work fine in gold chloride, in spite of concentration. I welcome a correction if I'm wrong. 

I'm not convinced that concentration would make a difference, though. If a material will cement another, there isn't a magic number where it won't, which is why a stock pot is so successful at recovering values. 

Harold


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## freechemist (Aug 10, 2011)

25 years ago, at the very beginning of my activities in industrial recovery/refining, I had to operate some Wohlwill cells the very first time, instructed by the engineer who planned and installed the whole chemical and electrochemical refining units. The racks to hold and contact anodes and cathodes were made of plain silver. The very first electrolysis-experiment rapidly showed up as a disaster, caused by heavy corrosion of the silver, leading to a rapid growing of the cell resistance and thus to rapidly sinking current flow. So the racks had to be replaced, and titanium was the material chosen. It worked successfully nearly endless, even without traces of corrosion.
Titanium as such is a very reactive metal, like aluminum, but covered with a very compact oxide layer on its surface, protecting it efficiently against attack with mineral acids, elemental halogens and strong bases. This very high chemical resistance leads to its industrial use as so called dimensionally stable anodes (DSA) in chlor-alcali-electrolysis and different electrochemical processes. In a DSA the original titaniumoxide surface layer, which is a very good electrical insulator, is replaced by a mixed oxide layer, for example a mixed titanium/ruthenium-dioxide layer, which conducts electrical current and is able to oxidize chloride to elemental chlorine at even lower potentials than a platinum- or a graphite-anode.


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## Harold_V (Aug 11, 2011)

freechemist said:


> 25 years ago, at the very beginning of my activities in industrial recovery/refining, I had to operate some Wohlwill cells the very first time, instructed by the engineer who planned and installed the whole chemical and electrochemical refining units. The racks to hold and contact anodes and cathodes were made of plain silver. The very first electrolysis-experiment rapidly showed up as a disaster, caused by heavy corrosion of the silver, leading to a rapid growing of the cell resistance and thus to rapidly sinking current flow.


That's interesting! I recall reading that, at one time, silver was the metal of choice for the buss in a Wohwill cell, and I expected that it would be troublesome. 



> So the racks had to be replaced, and titanium was the material chosen. It worked successfully nearly endless, even without traces of corrosion.


Thanks for confirming my hunch. I built a small Wohwill cell years ago, right down to making the mold for the anodes (roughly 5 ounces per anode). Never put it to work, in spite of having cast some anodes to part. I used titanium for the buss and racking system, hoping it would respond as you suggested. Now I have regrets for never having tried the system. I was so comfortable doing a second refining chemically (AR) that I simply stayed the course. Sold the cell, along with the refining business when I retired. To my knowledge, it was never put in service. 

Harold


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## utelectrode (Mar 16, 2022)

Mixed metal oxide coated titanium anodes are exclusively used in the metal recovery system. The system is composed of the deposition of an electrolytic cell at the cathode, in the metal you want to obtain. MMO coated Titanium Anodes that are immersed in a fluidized bed of non-conducting particles , this ensures that there are high levels of mass transport and low power requirements. The metal recovery system is used for the efficient recovery of metals from dilute solutions where conventional electrolysis cannot be considered.

The metals that can be recovered by this method are copper, nickel, zinc and cobalt, and used in the recovery of cyanide-based electrolytes of gold, silver, copper, zinc and cadmium cyanide is electrochemically destroyed, due to the enhanced anode efficiency.

Titanium substrate shapes: squares,rectangular sheets, strips, foils, plates, expanded metal and meshes, corrugated and perforated metal plates, wires, rods, discs, bars,tubes or according to clients' requirements.​


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## Elemental (Mar 16, 2022)

@utelectrode,

Any particular reason you are resurrecting a 11 year old post?

Elemental


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## Martijn (Mar 16, 2022)

Let me guess.... Spam marketing of shitty chinese products before markets get closed by international sanctions..... Ostriches. 
Full country's IP ban? 
That's about as political I dare to be here..sorry but I couldn't help it. 

Back to refining.


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