Contamined Cu/CuO-Au-Ag-Pd-Pt powder

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scorpion1971

Member
Joined
Aug 3, 2017
Messages
20
Dear forum members,

I have a small workshop at industrial zone. There is 15 tons about Cu and CuO mixed powder waste. (This waste content total 3~3.5 kg Au, 10.5~11 kg Ag, 550 gr Pd and 110 gr Pt.)
No electrolysis equipment. I think about the process in a simple and practical way.
First, the solution with 1: 1 distilled water: concentrated nitric acid. Copper, silver and palladium will dissolve. Gold and platinum will remain in the filter. AgNo3+Cu = Cu(No3)2 + Ag. If I add pure copper to nitrate solution (Cu+Ag+Pd) Ag and Pd drop?
Also, Au and Pt aqua regia dissolve OK. How I can selectively separate them?
Your help will be greatly appreciated.
Sorry bad English.

Regards,
Mehmet
 
15 tons processed wet chemically! I can't even start to compute those numbers. Your going to have to do something with all that copper first. You haven't told us what all else is in the mix by percentages. To make it cost feasible i would probably say copper sulfate cell first. You can then also sell the copper! 30,000 lbs copper is about $75- $80,000 dollars. Then the slimes can be refined in a concentrated state with very little cost or waste disposal issues.
 
If those numbers came from XRF, which is often not reliable, I would start over and get some true fire assays done. Since the bulk of the value is gold, I wouldn't worry about assaying the other metals. If you fire assay at least 5 samples, all pulled from different areas of the 15 tons, and if their gold value varies more than about 25% (a guess), you should use statistics to determine about how many samples you'll have to pull and assay to be within a chosen standard deviation.

If I did the math right, it would take about 300, 55gal drums of nitric acid to dissolve all that copper, depending on the CuO%. That would produce, AT LEAST, 600 drums of waste. Simple and practical -NO! The amount of heavy, very-visible, toxic, red-brown fumes would be huge. What would you do with 120,000 liters of dark bright blue, high copper waste solution?

With about a 1000 gallon copper cell and a 2000 amp power supply, at 100% efficiency, running 24 hours per day, it would take about 250 days. In reality, double that. For 2000 amps, it would require 4 square meters of cathode area and about the same in anode area. Of course, you would need a pretty good sized gas crucible furnace, preferably a tilt, to melt and cast cell bars. A lot of CuO might complicate the melting considerably. In the US, I think the EPA bases toxicity of heavy metal compounds on the solubility of that compound at a pH of 2. My guess is that the solubility of CuO at that pH would be high enough to warrant it being considered toxic waste.

Note: the figures above for using nitric or a Cu cell are only estimates.

At this point, the material is assumed to be worth only about $120,000. Considering what you would have to go through, and the costs and time involved, I would say this job is a HUGE LOSER, if you do it yourself. Even if it is free, I wouldn't touch it with a 10 meter pole unless I could find a copper smelter that would take it all and provide a good, honest (the key word) return. You might be able to get about 65% of the copper and about 90% of the PMs, but those numbers are only guesses, and they could be full of error.

I've seen a lot of "white elephants" like this, as big pie-in-the-sky deals are called in the scrap metal industry. Surely, whoever owns it now would have researched the possibilities of making money with this, or even giving it away for nothing, and came up dry. It sounds like they're looking for a sucker to take this toxic mess off their hands.

From what specific industrial process did this material originate from? Are the PM particles alloyed with the Cu or are they separate? What percent of the total is the CuO?
 
goldsilverpro said:
If those numbers came from XRF, which is often not reliable, I would start over and get some true fire assays done. Since the bulk of the value is gold, I wouldn't worry about assaying the other metals. If you fire assay at least 5 samples, all pulled from different areas of the 15 tons, and if their gold value varies more than about 25% (a guess), you should use statistics to determine about how many samples you'll have to pull and assay to be within a chosen standard deviation.

If I did the math right, it would take about 300, 55gal drums of nitric acid to dissolve all that copper, depending on the CuO%. That would produce, AT LEAST, 600 drums of waste. Simple and practical -NO! The amount of heavy, very-visible, toxic, red-brown fumes would be huge. What would you do with 120,000 liters of dark bright blue, high copper waste solution?

With about a 1000 gallon copper cell and a 2000 amp power supply, at 100% efficiency, running 24 hours per day, it would take about 250 days. In reality, double that. For 2000 amps, it would require 4 square meters of cathode area and about the same in anode area. Of course, you would need a pretty good sized gas crucible furnace, preferably a tilt, to melt and cast cell bars. A lot of CuO might complicate the melting considerably. In the US, I think the EPA bases toxicity of heavy metal compounds on the solubility of that compound at a pH of 2. My guess is that the solubility of CuO at that pH would be high enough to warrant it being considered toxic waste.

Note: the figures above for using nitric or a Cu cell are only estimates.

At this point, the material is assumed to be worth only about $120,000. Considering what you would have to go through, and the costs and time involved, I would say this job is a HUGE LOSER, if you do it yourself. Even if it is free, I wouldn't touch it with a 10 meter pole unless I could find a copper smelter that would take it all and provide a good, honest (the key word) return. You might be able to get about 65% of the copper and about 90% of the PMs, but those numbers are only guesses, and they could be full of error.

I've seen a lot of "white elephants" like this, as big pie-in-the-sky deals are called in the scrap metal industry. Surely, whoever owns it now would have researched the possibilities of making money with this, or even giving it away for nothing, and came up dry. It sounds like they're looking for a sucker to take this toxic mess off their hands.

From what specific industrial process did this material originate from? Are the PM particles alloyed with the Cu or are they separate? What percent of the total is the CuO?

Dear Master Chris,

Thank you very much your valuable comments. First one, I don't will pay this material. The job's procedure profit fifty fifty. Also Noxx emission not problem here.

Regards,
Mehmet
 
Mehmet no disrespect but we all are at risk from noxx emissions so are your neighbours, the problem you have is how to process this material at a profit, and in honesty using nitric will be very costly and possibly poison you and the environment for miles around plus you will have thousands if not tens of thousands of liters of toxic waste solution to dispose of, this is something we take very seriously, the safety of members and neighbours and the environment, we all share this planet and ignoring the dangers will not sit well here.
 
Mehmet, I want to reinforce what nick has said. We are all downwind of you, and everyone else on this forum. While you may not have any legal restrictions in your country, we must all be responsible in how we process and how we deal with our waste. Even if you don't care about the pollutants you add to the air we all breathe, the economics of processing that much material with nitric acid is against you. As others have suggested, the best option here may be to have a professional refiner deal with this material. It will produce much less toxic waste, and in the long run, it will be less costly.

Dave
 
I would be building a large tilt furnace which you will need anyway, and cast it into bars. Then assay and ship to Aurubis. They are a copper smelter and have very reasonable rates.

An electrolytic refining operation of this scale is not a learn as you go project.
 
4metals said:
I would be building a large tilt furnace which you will need anyway, and cast it into bars. Then assay and ship to Aurubis. They are a copper smelter and have very reasonable rates.

An electrolytic refining operation of this scale is not a learn as you go project.

Agreed depending what other metals are there it could quickly become a nightmare if the electrolyte keeps fouling quickly.
 
Agreed depending what other metals are there it could quickly become a nightmare if the electrolyte keeps fouling quickly.

Unfortunately our responses here on the forum are a direct reflection on how much information we are given. It seems obvious to me, in my little mind, that anyone venturing into an operation such as this would follow these simple steps;

1. Sample it yourself
2. Be as assured as possible that the sample is representative
3. Have the sample assayed for all PM's and base metals
4. If the results sound too good to be true get a second opinion (by a second assayer!)

Only after these 4 simple steps have been taken do you start acquiring the necessary equipment to move forward. It is my opinion, again in my little mind, that more money has been wasted trying to recover values from these schemes than has ever been made off of these schemes. Far better to invest a little money in the cost of sampling and testing, than to lose a boatload of money by being surprised at a poor outcome once it is too late.
 
4metals said:
I would be building a large tilt furnace which you will need anyway, and cast it into bars. Then assay and ship to Aurubis. They are a copper smelter and have very reasonable rates.

An electrolytic refining operation of this scale is not a learn as you go project.

I agree 100%. Only a fool would consider processing this himself. A copper smelter would just sample and assay it and then insert in into their normal flow pf copper material. At some point, the smelter will settle with you. It won't be immediately, but it would be a lot faster and a lot more profitable than your doing it yourself. And, as a bonus, you won't die from the fumes.
 
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