Things which may be of interest to members

[kurtak]

Kurt it depends on what type of solutions you are running in the cell and what metals you have in solution, it will do an excellent job of recovering values from base solutions which can be melted and sold as is or refined if that is your preference , with acidic solutions I believe by varying the voltage/ ampage it can be made selective to a degree or so I believe, trials were been conducted by another firm into how it could be done but assays are needed to check what is been stripped or left.

Nick

I get all of that --- concerning the underlined above I also understand that Jon is using it to "recover" his gold from his cyanide stripping solution so it seems to me that because the gold is being deposited at the cathode (carbon felt) the gold is then tied up with in the matrix of the felt & therefore you would then need to recover the gold from the felt

Being carbon it seems to me that you would therefore need to incinerate the felt to turn it to ash so that you could then ether smelt it to slag off the ash (& depending on the ash to gold ratio maybe even add a collector metal) or incinerate the felt to turn it to ash to re-leach the gold from the ash

Or am I missing something here ?

Kurt

 

[Anonymous]

Kurt it's perfectly fine to put your felt in AR and dissolve the gold from it.

Edit of course you need to wash it first if you're using a cyanide leach.

 

[kurtak]

Kurt it's perfectly fine to put your felt in AR and dissolve the gold from it.

Edit of course you need to wash it first if you're using a cyanide leach.

That doesn't make sense to me - as we know "carbon loading" is another method of recovery used to recover low PPM from acidic solutions --- that's why we ALWAYS advise that when leaching gold bond wires from incinerated IC chip that you make sure the epoxy is incinerated to "complete" ash - other wise if there is carbon in the ash you will suffer some degree of your gold due the gold chloride loading on the carbon --- not ?

Kurt

 

[kurtak]

The other option would be to sell the felt (once it is loaded with gold) to another refiner - but I would assume you would take a bit of a hit on price - which is not always a bad thing --- kind of like selling dore metal from a smelt - you take a bit of a hit on what you get paid for the PMs - BUT - you save on the chems needed & the time spent & the waste created trying to recover the PMs from the dore yourself

Kurt

 

[Yggdrasil]

Hi!

The way I understand it, you can AR the felt and extract most of the values.
Then attach the felt again and continue stripping with it until a point where you decide the felt is spent.
At that time incineration/fusion/smelting or similar methods has to be applied to completely recover whats in the felt?
Correct me if I'm wrong but the felt could be fine until its too degraded to retain its form.
Do anyone know how a felt like this, would hold up in weak or even strong sulfuric acid?

 

[g_axelsson]

If it's loaded with gold you should be able to melt it directly, if you are using an oxidizing flame (or environment / flux) the carbon should just burn away. Just like melting gold in a filter paper that some members do regularly.

Another solution would be to run the cell in reverse, using the felt as anode and deposit the gold on a massive carbon cathode or a metallic cathode, preferably of pure gold. This could be made as a second smaller loop. If it's possible to increase the amperage with a more concentrated electrolyte it would take shorter time to run the "unload" phase.

Göran

 

[kurtak]

Do anyone know how a felt like this, would hold up in weak or even strong sulfuric acid?

Probably not well - it would most likely ash the felt - its called wet ashing

Kurt

 

[Yggdrasil]

Thanks Kurt.
So its wise to keep the sulfuric out of the leach if one plan to run this cell :lol:

 

[kurtak]

If it's loaded with gold you should be able to melt it directly, if you are using an oxidizing flame (or environment / flux) the carbon should just burn away. Just like melting gold in a filter paper that some members do regularly.

Göran

Yes - doable - however not quite as simple as putting a paper filter in a melting dish & ashing it - paper readily ashes - not all carbon readily ashes (keep in mind diamonds are carbon)

Example - here is carbon fiber felt used for welding blanket insulation that withstands 1800 degrees (I assume that is 1800 F) :arrow: http://www.autobodytoolmart.com/velvet-shield-carbon-fiber-welding-blankets-p-39772.aspx?utm_source=bing&utm_medium=cpc&utm_campaign=Bing%20Shopping&utm_term=1100001935516&utm_content=All%20Products

That's close to the melt temp of gold (1947.52 F) so its not going to readily ash - & the felt cathode from the cell is quite large so its not going to happen in a dish with a torch

You could load the felt in a crucible & then "first" ash it in the furnace - then add your flux --- however I am not sure you would get complete ashing because the gold is loaded "on" the fiber - therefore the gold is going to be somewhat of a passive layer preventing oxygen from getting to the carbon to completely ash it - so you would likely need to add an oxidizer to the flux ( like potassium nitrate - very hard on crucibles) --- if the gold to ash ratio is not high enough (in gold) you would also need a collector metal (silver would be preferred though copper would work) to prevent ball metal hanging up in the slag - in which case you then would need to part the gold from the collector metal

Another solution would be to run the cell in reverse, using the felt as anode and deposit the gold on a massive carbon cathode or a metallic cathode, preferably of pure gold. This could be made as a second smaller loop. If it's possible to increase the amperage with a more concentrated electrolyte it would take shorter time to run the "unload" phase.

This is also doable - I guess my point is that with recovery by "winning" with this cell involves added steps before your final product of a melted bar/button --- unless I am missing something

The positive side to the winning cell is that you recover your leach solution so that it can be re-used thereby significantly reducing your waste

Edit to add; - by the way - I think I just found a more affordable source for the carbon felt in the above link - that price is way lower then other prices I have seem

Kurt

 

[Yggdrasil]

Hi!
A couple of thoughts.

If it is hard to ash it in an oven/kiln/furnace etc.

Yggdrasil wrote:
Do anyone know how a felt like this, would hold up in weak or even strong sulfuric acid?

Probably not well - it would most likely ash the felt - its called wet ashing

Is it possible to wet ash it as mentioned above? (It has after all relatively low carbon volume)
Or would a passive layer come into play even then?

And if so, how would one treat it after, to recover the values?

I found the same welding mats, but guessed that they were made of a different quality carbon and disregarded them..
Since it is made from"carbon fiber" I was of the idea that each fiber is stronger slicker and has a more compact form.
The carbon felt for sound proofing would be better off, if they were made of more porous graphite style fibers.
If this is correct this carbon felt, may have a significantly lower ashing temperature.
Anyone here with some actual information to set me straight?

 

[Anonymous]

Kurt it's perfectly fine to put your felt in AR and dissolve the gold from it.

Edit of course you need to wash it first if you're using a cyanide leach.

That doesn't make sense to me - as we know "carbon loading" is another method of recovery used to recover low PPM from acidic solutions --- that's why we ALWAYS advise that when leaching gold bond wires from incinerated IC chip that you make sure the epoxy is incinerated to "complete" ash - other wise if there is carbon in the ash you will suffer some degree of your gold due the gold chloride loading on the carbon --- not ?

Kurt

Are you sure you're not talking about activated carbon?

 

[Anonymous]

If it's loaded with gold you should be able to melt it directly, if you are using an oxidizing flame (or environment / flux) the carbon should just burn away. Just like melting gold in a filter paper that some members do regularly.

Another solution would be to run the cell in reverse, using the felt as anode and deposit the gold on a massive carbon cathode or a metallic cathode, preferably of pure gold. This could be made as a second smaller loop. If it's possible to increase the amperage with a more concentrated electrolyte it would take shorter time to run the "unload" phase.

Göran

No that defeats the whole object of the cell Goran. Think surface area and a single path of liquid from outside to inside. The liquor outside has values, inside it does not.

 

[g_axelsson]

If it's loaded with gold you should be able to melt it directly, if you are using an oxidizing flame (or environment / flux) the carbon should just burn away. Just like melting gold in a filter paper that some members do regularly.

Another solution would be to run the cell in reverse, using the felt as anode and deposit the gold on a massive carbon cathode or a metallic cathode, preferably of pure gold. This could be made as a second smaller loop. If it's possible to increase the amperage with a more concentrated electrolyte it would take shorter time to run the "unload" phase.

Göran

No that defeats the whole object of the cell Goran. Think surface area and a single path of liquid from outside to inside. The liquor outside has values, inside it does not.

You have to see it like a silver cell, in this case we would disconnect the carbon felt cell from the original leach tank and replace the weak cyanide solution with something more concentrated, like a gold plating solution.
If we are using the felt with the gold deposit as an anode then we could just put a cathode in the center of the cell and have the gold deposited on it.

But it all comes down to the price of the carbon felt, if it is cheaper and more convenient to just replace it

Göran

 

[Anonymous]

If it's loaded with gold you should be able to melt it directly, if you are using an oxidizing flame (or environment / flux) the carbon should just burn away. Just like melting gold in a filter paper that some members do regularly.

Another solution would be to run the cell in reverse, using the felt as anode and deposit the gold on a massive carbon cathode or a metallic cathode, preferably of pure gold. This could be made as a second smaller loop. If it's possible to increase the amperage with a more concentrated electrolyte it would take shorter time to run the "unload" phase.

Göran

No that defeats the whole object of the cell Goran. Think surface area and a single path of liquid from outside to inside. The liquor outside has values, inside it does not.

You have to see it like a silver cell, in this case we would disconnect the carbon felt cell from the original leach tank and replace the weak cyanide solution with something more concentrated, like a gold plating solution.
If we are using the felt with the gold deposit as an anode then we could just put a cathode in the center of the cell and have the gold deposited on it.

But it all comes down to the price of the carbon felt, if it is cheaper and more convenient to just replace it

Göran

No I don't have to see it like a silver cell. Goran this is a practical item that works. You can theory craft as much as you like but you know sometimes you actually have to .. do something? You know? Go out there and build one but until you have, then enough of theoretical improvements that effectively break the principle of something that works in practice.

If you built one you would understand I can promise you.

 

[kurtak]

Kurt it's perfectly fine to put your felt in AR and dissolve the gold from it.

Edit of course you need to wash it first if you're using a cyanide leach.

That doesn't make sense to me - as we know "carbon loading" is another method of recovery used to recover low PPM from acidic solutions --- that's why we ALWAYS advise that when leaching gold bond wires from incinerated IC chip that you make sure the epoxy is incinerated to "complete" ash - other wise if there is carbon in the ash you will suffer some degree of your gold due the gold chloride loading on the carbon --- not ?

Kurt

Are you sure you're not talking about activated carbon?

Yes - activated carbon is what's normally used for gold carbon loading - I am also aware that there are different types of carbon - graphite is a type of carbon - very high temp carbon which is why its used for crucibles & molds & I don't "think" it would load like activated carbon --- concerning the carbon felt I was unsure so had to ask mate :mrgreen: (which is why I kept say - "unless I am missing something") --- after all "your the man" actually running this cell 8) 8)

Looks like I am going to have to buy that 4'X6' welding blanket I posted a link to - $100 is not a bad price

Kurt

 

[kurtak]

After doing a little more looking around I also found this one :arrow: http://www.mscdirect.com/product/details/93215853?src=pla&cid=PLA-Bing-PLA+-+Test&CS_003=61497716&CS_010=93215853&cid=PLA-Google-Shopping+Campaign+Test%28BSC%29_swzaS38Ch|dc_PLA__11490253749_c_S&mkwid=swzaS38Ch|dc&pcrid=11490253749&src=pla

its a bigger piece 6'X8' instead of 4'X6' for $283 so a bit more expensive - but if you look at the description it gives 1800 F as the max heat temp but right under that it also says 200 F "constant" max temp so "assume" it would ash & then smelt if smelting would be the choice of recovery --- & I would assume this would be true with any of the carbon felt welding blankets

Kurt

 

[Anonymous]

They work getting plating solutions down to 1 ppm and have been around for 30 years. They have a platinized titanium anode. Maybe it wouldn't grab everything first pass but they melt nice.

I missed the second part of your post earlier 4metals. Yes a platinised Titanium Anode is great for this cell. The main consideration though for the proof of concept unit that I initially built was cost. For most home users too I would imagine the same would apply. A graphite rod is way cheaper, but for sustained, high volume throughputs I will certainly invest in the anode you suggested.

This in turn raises another point. If you are looking to scale the diameters of the cell down, then you need to replace the single internal return (barren liquor) with at least 4 because it provides a flow from multiple points within the cell and prevents a build up on one point of the cathode. This can be achieved simply by using T pieces on the pipe to provide multiple ends.

Jon

 

[hadriansluicer]

Hi. Is my first post on the forum ,after a lot of reading. English is not my first language so I m apology for mistakes. Firs I want to thank you for the huge amount of knowledge I ghatered here. I understud the rules of board,and when something was not clear I read again and again,until all is settle nice. Reading Deano post about ferocyanate leaching,wanted to try it.i go to eBay to get some ferocyanate and read msds sheet. They wright there -in contact with acids is releasing toxic gases(one of msds speak of hydrogen cyanide :shock: . Deano use is leach at ph 1-3,with addition of sulfuric acid. My question -it is safe? Sorry for taking your time but msds was little disturbing,so I must to ask. Don't want to kill anyone of my neighbors ,thought I like it a lot :lol:

 

[hadriansluicer]

Thyocyanate. Sorry

 

[hadriansluicer]

http://www.labchem.com/tools/msds/msds/75510.pdf thiocyanate,sorry.