I think this article is not even close to useful.
Anything pyrolized needs to be incinerated afterwards or the Carbon will capture at least some amount of Gold.
This is publishing material not usable factual processing.
Is Sodium hydroxide best solution to git rid of tin and lead?
- Thread starter Ayham Hafez
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Anything pyrolized needs to be incinerated afterwards or the Carbon will capture at least some amount of Gold.
This is publishing material not usable factual processing.
"The final recovery rates were approximately 90 and 93% when using the oxidants of hydrogen peroxide and perchloric acid, respectively. "
There is totally incorrect information about thiourea and thiosulfate leaching processes. The article was written for PR purposes and most likely did not edited by professional scientists.
There is totally incorrect information about thiourea and thiosulfate leaching processes. The article was written for PR purposes and most likely did not edited by professional scientists.
Just throwing this out there, with the volume you're saying and not knowing your budget, shop size or where you want to take your endeavor. Perhaps something in the line of this equipment may alleviate processing issues. PCB Recycling Equipment | Cable Recycling Machine | Aluminum Plastic Separator - SUNY GROUP MACHINE
Not saying to buy their equipment specifically, but often machines can be your best option.
Not saying to buy their equipment specifically, but often machines can be your best option.
Ayham Hafez
Well-known member
I think we can get the clear comparison between hydrometallurgy and pyrometallurgy by recording IC chips recovery using incineration, grinding etc... and Ic chips recovery using sulphuric acid, for me the recovery rate is much higher using sulfuric acid but I always have issues with it because usually I process large quantities and to make it possible to be done in one batch we need large stainless steel pot, yesterday I bought stainless steel pot that is 100% not magnetic inspite of that sulfuric acid dissolve it!!
Do that mean you are wet asking the chips?
That is beyond dangerous.
Hot boiling concentrated Sulphuric will burner and dissolve your skin and fresh in no time.
Could you explain how this was dealt with? What damages occurred? Anyone hurt or have problems breathing?
For concentrated Sulphuric I think mild steel will do. At least cold.
Ayham Hafez
Well-known member
In general I deal with chemicals in open place, and alone, so nothing bad happen
Ayham Hafez
Well-known member
Cold sulphuric acid will not dissolve ic chips plastic
Stainless steel is not resistant to sulfuric acid (at least the standard brands which are used to make pots). Stainless steels 304 or 316 are not recommended for use with sulfuric acid. Use carbon steel for concentrated H2SO4. Or try to find vessel made from stainless steel 904, which is sulfuric acid resistant.
Ayham Hafez
Well-known member
Yes, now I learned the lesson
Attachments
I agree,
"...Approximately 20 g of waste PCBs was used for each microwave pyrolysis experiment. To maintain the inert atmosphere of reaction cavity, it was purged by pure nitrogen gas at a flow rate of 100 mL min− 1. After sufficient purging, the microwave oven was turned on and switched to the microwave power levels of 150, 200, 250, 300, 350 and 400 W for 60 min...."
So a quick calculation gave me this.
1t = 1000000 gr.
1000000gr/20gr=50000
400W = 0.4 kW
1kW energy = 0.2104 Euro => 0.4kW = 0.08416 Euro/hour
50000x0.08416=4208 Euro just for the pyrolysis of 1t of material
https://media.springernature.com/fu...8-x/MediaObjects/42834_2022_118_Fig1_HTML.png
Following the above flowchart, by the end of the process, you look forward to a huge loss rather than "...The gold recovered from 1 t of waste PCBs can be sold for approximately USD 10,000, and thus the return on investment can be as high as approximately 1400%...."
Pete.
You really do not want to do wet ashing of anything.
It is way too dangerous and comparable to HF which will kill you if it can.
Ayham Hafez
Well-known member
Hmmm, I also use HF as a final preparations of ceramic CPUs, I use it very carefully, wet processing increase the recovery rate more than 10%
Only if you do something wrong.
How about fixing your processes?
And how do you treat your chemical waste?
Ayham Hafez
Well-known member
I waste a lot of NaOH for chemical treatments.
I think the better way is to move to pyrometallurgy, but I have no skills at all with it specially that I deal with large quantities of E-waste every month
Once more!
How do you treat your chemical waste?
And what is large quantities to you?
How much is "large quantity of e-waste" for you. For me is like 10-15t/day of material. How about you?
Pete
Ayham Hafez
Well-known member
Usually I add NaOH till PH is more 7, I process about 2 ton per month, my workshop has no machines, just labors for dismantling and rest of work done by only myself
Read the thread about dealing with waste:
https://goldrefiningforum.com/threads/dealing-with-waste.10539/
2 Tons a month is more in the realm of small scale, just 100Kg a day.
Large hobby scale though
