Thanks again Deano.
Things which may be of interest to members
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Hi I'm going to do an unconventional stunt this time.
I'll post a PDF document since it have pictures and text together and I felt it would behave better in a PDF.
Anyways I hope someone has some views and information regarding the content in the PDF.
Regards Per-Ove
I'll post a PDF document since it have pictures and text together and I felt it would behave better in a PDF.
Anyways I hope someone has some views and information regarding the content in the PDF.
Regards Per-Ove
PeterM
Well-known member
Filter through a tight filter, or wash into a porcelain spoon dry, or extract most of the liquid with a small piece of tissue paper, then dry, anneal then scope it... then show me.... if it's gold it will be Crystalline.
The Ore owner has prepared a electrolytic cell with tin cathode as per recommendation from “Extraction of Gold Ore" 1905, Dickey
The funny thing is that when he adds approximate a ml leach to the spoon and then more or less the same with Stannous. Both crystal clear. This black precipitate collects in a point in the bottom. Deano has already said that Hypochlorite leach do not fare well with stannous due to high amount of oxidiser and salt.
But it still is a bit cool how the powder just emerges out of nothing.
The funny thing is that when he adds approximate a ml leach to the spoon and then more or less the same with Stannous. Both crystal clear. This black precipitate collects in a point in the bottom. Deano has already said that Hypochlorite leach do not fare well with stannous due to high amount of oxidiser and salt.
But it still is a bit cool how the powder just emerges out of nothing.
Hi Per, I didnt realise you posted images of the spoon tests, anyway, attached are images of the the spoon test particles (reduced/precipitated by the stannous) as seen through the microscope at 100x, DF, no filters. Sorry for the late posting. The cubic crystals are salt from the hypo leach. Testing is still on going as you know
.Attachments
A wonderful thread by Deano ( many thanks to you ), more to read from him. However, I had a set of questions for clarity and understanding, but I also have another thread lined up for reading so do I post these questions straight up or will it be better to ask after going through this thread below?
https://goldrefiningforum.com/threads/further-things-which-may-be-of-interest-to-members.22978/
https://goldrefiningforum.com/threads/further-things-which-may-be-of-interest-to-members.22978/
Hello again,
Some questions I had after going through this thread,
1, I've found a carbon felt with the following features, please let me know if these would be good enough for this:
3, Speaking of volatilization, is it only gold in chloride from that may evaporate or are we considering its metallic form here as well?
4, (This is for my understanding and anyone going through it) I really like the recirculating cell, but like Deano has mentioned here that undisturbed activated pica carbon would also be a good adsorbent for loading, how if the same was used inside the perforated PVC pipe instead of the carbon felt wrapping? It stays undisturbed and even if attrition does so take place, the miniscule particles may stay within the pipe given it was wrapped by another material or fabric? This is if we entirely substitute the idea of electrowinning.
5, For all of the mentioned techniques and processes, the use of AAS or AA was found very common. These units aren't an easy buy specially for the small scale home refiners. Is it possible to work without these?
More questions for later, for now thanks all for your time on this one
Some questions I had after going through this thread,
1, I've found a carbon felt with the following features, please let me know if these would be good enough for this:
- A blanket-like carbon felt made by pre-oxidation and carbonization of a polyacrylonitrile-based flat felt.
- Soft texture, light weight, small heat, good heat insulation, easy to cut, easy to operate.
- Corrosion resistance, high temperature density and high leakage.
- High life and energy saving.
- Used in vacuum furnace, induction furnace thermal insulation energy storage , experimental conductive electrode gas adsorption material, filtering and removing stains.
- Technical indicators:
- Carbon content: 98% or more
- Moisture absorption rate: 2%
- Use environment: air 350 ° C
- Vacuum 1800 ° C
- Inert gas 2650 ° C
- Specific resistance: (Ω.mm2/m)
- Horizontal: 8.2-11.1x10 cubic
- Vertical: 11.8-16.8X10 cubic
- Application areas:
- 1. Can be used as a flame retardant material in the thermal insulation industry;
- 2. As a porous material, it can be used as a catalyst carrier in the chemical industry;
- 3. Can be used as a corrosion-resistant material for the inner liner or outer protective layer of composite materials.
- 4. It can be widely used as a conductive, absorbing and absorbing material in aviation, batteries, electrodes (such as electrode tubes, electrode rods, etc.); currently, applications related to conductive concrete are also rapidly developing.
- 5. It can be used as adsorbent material for decontamination of gas and ; gas industry such as desulfurization and denitrification; and carbon fiber felt has high temperature resistance, which can be used for high temperature removal in heavy polluting industries such as plants and sulfuric acid plants. Pollution industry; s such as oil absorption;
- Colour: black
- Material: Carbon felt
- size:5*200*300mm
- Package Contents:
- 2 * Carbon Fiber Welding Blanket
3, Speaking of volatilization, is it only gold in chloride from that may evaporate or are we considering its metallic form here as well?
4, (This is for my understanding and anyone going through it) I really like the recirculating cell, but like Deano has mentioned here that undisturbed activated pica carbon would also be a good adsorbent for loading, how if the same was used inside the perforated PVC pipe instead of the carbon felt wrapping? It stays undisturbed and even if attrition does so take place, the miniscule particles may stay within the pipe given it was wrapped by another material or fabric? This is if we entirely substitute the idea of electrowinning.
5, For all of the mentioned techniques and processes, the use of AAS or AA was found very common. These units aren't an easy buy specially for the small scale home refiners. Is it possible to work without these?
More questions for later, for now thanks all for your time on this one
The carbon felt I used was sold as sound insulating material but appeared to be similar to other types sold for other uses.
I suspect that most is very similar material with a marketing slant for whichever market the sellers were targeting.
The felt I used came in a range of thicknesses, 5 to 10mm were the ones most used depending on price and required flow rate.
If I am going to use a carbon part in a process where the part is wetted by a gold solution I always put the part in a gold solution of known tenor and check the gold tenor after 30 minutes or so to see if any adsorption has occurred.
Usually what I find is that gold adsorption is minimal at most, certainly not levels which would concern someone using the part in a processing route.
It appears that people do not understand the difference between industrial carbon and activated carbon and the word carbon is enough to make unwarranted assumptions about gold adsorption.
It is easy to do testing to find out the level of gold adsorption on any material but is really only possible if you own or have cheap access to an AA or similar.
If you are serious about doing larger scale gold recycling then an AA is virtually a necessity as you can instantly see what gold levels are in your liquors and you can then adjust your chemical inputs to suit.
For most gold work you are looking at a "bare bones" model AA, you do not need all of the options beloved by the designers of these units.
What you do need is an AA model with background correction to compensate for base metals and organics in solution.
Most models have background correction as standard but a surprising number do not, always check.
There are cheapish models available from some manufacturers, secondhand is always an option.
You can purchase carbon and resin cylinders for removal of metals from liquid flows through these cylinders.
Any activated carbon used in these cylinders is usually pre-attritioned on a screen to minimise gold losses on the fines.
You will still need to ash the loaded resin for the gold recovery step.
Gold volatilising is really dependent on the surface area of the gold you are heating.
If you have the gold present at near atomic size particles it will volatilise at much lower temperatures than quoted in the literature.
My suspicion is that the volatilisation of gold chlorides mainly gets prominence due to the high surface area of such chlorides especially when disintegration of the chloride complex occurs at temperature.
Deano
I suspect that most is very similar material with a marketing slant for whichever market the sellers were targeting.
The felt I used came in a range of thicknesses, 5 to 10mm were the ones most used depending on price and required flow rate.
If I am going to use a carbon part in a process where the part is wetted by a gold solution I always put the part in a gold solution of known tenor and check the gold tenor after 30 minutes or so to see if any adsorption has occurred.
Usually what I find is that gold adsorption is minimal at most, certainly not levels which would concern someone using the part in a processing route.
It appears that people do not understand the difference between industrial carbon and activated carbon and the word carbon is enough to make unwarranted assumptions about gold adsorption.
It is easy to do testing to find out the level of gold adsorption on any material but is really only possible if you own or have cheap access to an AA or similar.
If you are serious about doing larger scale gold recycling then an AA is virtually a necessity as you can instantly see what gold levels are in your liquors and you can then adjust your chemical inputs to suit.
For most gold work you are looking at a "bare bones" model AA, you do not need all of the options beloved by the designers of these units.
What you do need is an AA model with background correction to compensate for base metals and organics in solution.
Most models have background correction as standard but a surprising number do not, always check.
There are cheapish models available from some manufacturers, secondhand is always an option.
You can purchase carbon and resin cylinders for removal of metals from liquid flows through these cylinders.
Any activated carbon used in these cylinders is usually pre-attritioned on a screen to minimise gold losses on the fines.
You will still need to ash the loaded resin for the gold recovery step.
Gold volatilising is really dependent on the surface area of the gold you are heating.
If you have the gold present at near atomic size particles it will volatilise at much lower temperatures than quoted in the literature.
My suspicion is that the volatilisation of gold chlorides mainly gets prominence due to the high surface area of such chlorides especially when disintegration of the chloride complex occurs at temperature.
Deano
First of all thankyou so much for your valuable time to post a reply and I apologize for getting back late as I am finding it difficult to manage my own based on the errands I've to run these days.
Thanks for your time again
To begin with, I couldn't agree more with this but I found this out on a local online portal here like Amazon (although not as big). Although the seller is Chinese but little would we think of its authenticity when it comes to being openly laid out onto the portal for purchase. It doesn't have any previous sales and also, it isn't very expensive. On the other hand I can also procure a platinized titanium anode that too very cheap and that is something that enhances my suspicion too since platinum plated wouldn't be as cheap as it is shown.
Like you have pointed out, this then probably needs some sort of internship under experienced guidance in order to get an acquainted understanding of the visual-adsorption of the gold itself?
Although I'm not anywhere near it now, but I think it would be best suited to be better prepared for IF there are any future plans for pursuing it. The more the study the better preparations right? so I'll consider understanding the use and mechanics of an AA indefinitely. For now if it is highly suggested for this operation, then ill drop this course of action and learn more about it.
I'll surely go by this rule even if I go for it at a later time.
Speaking of the IC chips in lieu of the aforementioned, they contain microscopic gold bonding wires if not atomic and they're well packed inside the ceramic epoxy carbon casing etc. As I mentioned earlier that the carbon needs be roasted at a higher temperature to become inert in nature. So the case in question : If we roast the carbon, we risk losing gold to volatilization. If we don't, we risk it being adsorbed onto the carbon. In my humble seek for knowledge sir, what would be your suggestion in this case then?
Thanks for your time again
Your "microscopic bonding wires" are massive in comparison with gold atoms and the amount of gold volatilised from these wires would be minimal in a standard roasting operation.
You can always roast with the temperature way too high or for far too long and achieve greater losses but these losses are purely of your making.
How do you actually know that unroasted chips will adsorb gold during leaching, have you done testing yourself or are you just basing this opinion on comments from other people who also have not done any actual testwork.
Do your own testing and prove to yourself what volatilisation, if any, occurs under the conditions you use during roasting.
You should also be checking what adsorption of gold from solution occurs if the chips are not roasted, this way you have actual data on the two options.
Deano
You can always roast with the temperature way too high or for far too long and achieve greater losses but these losses are purely of your making.
How do you actually know that unroasted chips will adsorb gold during leaching, have you done testing yourself or are you just basing this opinion on comments from other people who also have not done any actual testwork.
Do your own testing and prove to yourself what volatilisation, if any, occurs under the conditions you use during roasting.
You should also be checking what adsorption of gold from solution occurs if the chips are not roasted, this way you have actual data on the two options.
Deano
kurtak
Well-known member
I am not sure I understand your question here
Are you asking - will gold be volatized by roasting the carbon from epoxy chips "before" leaching
If that is your question - then no - gold will not be volatized when roasting the carbon to turn the carbon to ash if your are doing it BEFORE leaching
On the other hand - if you do not turn the carbon to ash BEFORE leaching - then yes - during leaching - gold can be absorbed onto the carbon - & then - if you go to roast the carbon (to turn it to ash) AFTER leaching - you " "risk" volatizing gold
Also - ceramic IC chips & epoxy IC chips should not be processed in the same batch - they are two different types of chips & therefore processed in two different ways
Kurt
This clears a boatload in terms of concept clarity in terms of relativity of the variables involved.
As per this, I believe it had been discussed a lot of times around the forum in terms of the conceptual nature of carbon involved in the process. Not during leaching however, but before that post pyrolysis and incineration. In terms of the actual test work, I've read comments of other experienced members about its specific requirement to be roasted hence, the concern (of volatilizing) grew there. So maybe not a test work but for some, processing the IC chips has been done for a living like @kurtak himself.
This seems like a doable test. Thankyou for that direction. Hopefully if I get the right time, I'll definitely carry out a test or if anyone does before me, would be a great help too
Yes, that was my question which you have answered in your very next statement. Thanks for that
Right, I may have have mixed them up
Good evening sir,
I was in a rush the last time around and unfortunately missed a very vital part over here. The issue I'm actually confused with is this - during the standard roasting operation, the charge seemed white. However, when I added water post-incineration to further remove the ashes I still see so much black, just like black sand. Is it still going to be a concern? Will I need to further roast it or should be ok if I'm to use wet chemistry over it?
Also if the equipment I hold does not have enough strength to incinerate all the material properly.. will the roast then flip the charge into a bucket of cold water help me here to release all the entrapped particles or is neither of it necessary and I just continue with routine leach with the blacks?
Thanks for your time
Usually one need more than one round of roasting.Good evening sir,
I was in a rush the last time around and unfortunately missed a very vital part over here. The issue I'm actually confused with is this - during the standard roasting operation, the charge seemed white. However, when I added water post-incineration to further remove the ashes I still see so much black, just like black sand. Is it still going to be a concern? Will I need to further roast it or should be ok if I'm to use wet chemistry over it?
Also if the equipment I hold does not have enough strength to incinerate all the material properly.. will the roast then flip the charge into a bucket of cold water help me here to release all the entrapped particles or is neither of it necessary and I just continue with routine leach with the blacks?
Thanks for your time
Before grinding and after grinding, what it comes down to is if it has been thoroughly roasted through so all the Carbon has been ashed.
I may have done about 3 -4 rounds of good incineration by now but I still se so much black, why? I plan on carrying on with HCl and Nitric leaches then re-incinerate before leaching with AR. I did a sample batch some time ago using HCl and peroxide which did a pretty good job. But my observation, I could see that the leaching wasn't complete although there was no further reaction going albeit the use of a stir bar. This observation was made when I could see some golden stuck between the black sand in the mix during the filtration process. This is what makes me skeptical of continuing with this process further.
The usual way to process these are gravity separation after milling, incineration and removal of the magnetic material..
The amount of material left after this is just a fraction of the starting material.
And a last roasting to low red with stirring will make sure that there are no Carbon left.
kurtak
Well-known member
That is likely very SMALL pieces of silicon from the silicon dies in the chips as a result of the silicon being broken down to very small pieces when milling the chips
Kurt
I did gravity after the pyrolysis, then proceeded with further roast- incineration. Washed more ashes, when no more ashes were visible I dried and rewashed even more ashes. So you see there were multiple rounds of frying it up.
Unfortunately this is what I want too and I'm unable to achieve it.
I used the mason jar for breaking the ICs down to separate the silicon dies (still separate in solid form), and here again, I wish the quantity was small and insignificant. I don't know how to phrase it but it seems like a bed of black carbon under the light-heavy material when water is brought into play.
Can you pick up a piece of the black "sand" and see if it is Carbon like or glassy?
How much material is left?
All magnetics removed?
