Urgent help needed: process for extracting copper from spent etching solutions!
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Urgent help needed: process for extracting copper from spent etching solutions! I have recently purchased a large quantity of used PCB etching solutions containing copper, and these solutions come in both acidic and alkaline forms. I intend to extract copper through extraction-electrodeposition methods, but since I am not an expert in this area, I am seeking advice from experts here; please offer your guidance!
In what state does copper exist in solution? What is a medium? If it’s acidic, what is the pH value? For alkalis, what is the pH value?
I measured it with a pH meter and the result was 05; I still don’t understand what this number means. The usual range is 0.0–14, so does a value starting with 0 indicate a higher acidity? The medium is a chloride system containing ammonium salts with a copper content of 100 grams.
With such high levels of copper, and the presence of both acidic and alkaline solutions, it’s best to directly neutralize the two, resulting in the formation of copper salt precipitates, which can then be dissolved in sulfuric acid to produce salts such as copper sulfate!
Neutralization precipitation was considered, but it’s not feasible in practice: first, the cost is too high; even when the two substances are mixed in a 1:1 ratio, a large amount of alkali is still required. Second, the solution contains chelating agents, which make complete precipitation difficult! :L is still considering extraction; who can give some advice?:'
I’m sending you two articles for reference (attachments cannot be uploaded here): http://bbs.hcbbs.com/viewthread.php?tid=424869&extra=page%3D1&frombbs=1. This post was last edited by lxm58 on 2009-3-24 at 21:27.]
It can be directly electrodeposited into copper plates, using titanium electrodes and stainless steel cathodes
Has it been done in production? I have simulated it: under ammonia conditions, electrowinning yields only copper powder, chlorine gas is released at the anode, and the operating conditions are poor
To control current, voltage, copper concentration, etc., no chlorine gas is produced; however, ammonia gas is recovered to form ammonia water, and the copper obtained through electrowinning is in the form of copper plates. The copper concentration in the solution can be reduced to below 1 g/L, with attention paid to maintaining the appropriate control conditions
Impressive, truly impressive. Electrodeposition is used to produce copper plates, and it’s possible to reduce the copper concentration in the solution to below 1 g/L. Which research institute or university is responsible for this? This post was last edited by memory1980 on 2009-3-28 18:54.]
The person upstairs is really amazing; they’re able to extract copper to that level.