Recycle your used Acid Peroxide.

[lysdexic]

The water soluble starting CuCl2 is dissolved into the fresh solution as it forms. As more copper is dissolved into the solution by the etch the two chlorine atoms are spread across two copper atoms becoming 2CuCl which ultimately saturates the solution as the process repeats and CuCl eventually precipitates as as solid. Adding more HCl dissolves the CuCl as it is soluble in concentrated HCl. If an oxidizer (O2, electrons, etc.) is present, the CuCl2 regenerates and the solution becomes useful again.

The overall reaction is mainly dependent upon the solubility of the active ingredient, CuCl2 and the free HCl in the solution.

1) There should be no sediment forming (insoluble CuCl, tested by adding a few drops of water: Whitish sediment when water added = saturated with CuCl).
2) There should be free HCl in the solution (to keep the CuCl dissolved).
3) There should be a source of oxygen supplied over the course of the reaction (to keep the converting the CuCl back to CuCl2).


Of course, this an overly simplified explanation of the reaction, but it does describe the key points to keeping your solution fresh and ready to consume more copper.

Steve

Thank you Steve, I can't really put anything together right at the moment, had a migraine all day. With all the ground work you've done and the willingness of yourself and the other experienced member's to help me (and all the other apprentices and journeymen) I'm (we're) learning. I need to read your pdf again and go over all these posts again before saying any more. I want to be clear with what I do understand and what I'm unsure of so I don't waste the most valuable resource here... all of you guy's time.

I also read the topic you linked to concerning the mason jar acquaintance experiment and have that tumbling around in my head too right now. Thank you again.

Doug

 

[butcher]

This kind of reminds me of something, I have done water treatment for boilers for many years, as a boiler man, I never had a chemistry lesson, picked it up in the working environment and leaned it pretty much on my own, most people who done this work didn't really understand chemically what was happening in the tests they performed, but they knew how to do the tests and add chemicals or make adjustments accordingly as needed, we normally had chemical and equipment sales men who were chemist who would also be advisers, one was fairly amazed at my understanding of the chemistry and the process and what was going on chemically with the water, but he would get very mad and argumentative when I called the minerals in water "rock" like calcium magnesium, silicates...

What was funny after working with me for several years he sometimes began calling the minerals in water "rock" also, especially when we would discuss the scale in the boiler. because that is where the minerals came from, and basically what they were, I knew they were minerals and He did too, but the important thing is that we understood each other, with the words we used, and understood the important parts of the communication getting our points across.

Actually I think he learned quite a bit from me (maybe as much as I learned from him) besides using the wrong words to describe the minerals. I have worked as a boiler man for many years, and knew and practiced some of the older chemistry used, some of which the modern chemist may not learn with the more modern chemicals they use today, to do the same thing that we done with things that were not actually considered chemicals, but that when added to the boiler would produce a chemical reaction, understanding these older chemical reactions (which were basically the same chemistry they were using with these modern chemicals), gave me a little advantage on understanding the chemistry going on with these newer chemicals (with names, that were like what shore company uses to keep their chemicals at a high cost,a trade secret, and you can only get it from their company, and the main reactive component of their chemical a trade secret), many of these were common chemicals, or slight modifications to a common chemical like sodium sulfite, basically being sodium sulfite but with names like there company's name followed by BSD 133.

I went to a big lab (a friend there who was a head lab technician for many years) and asked him to help me with some chemistry questions, he was astonished by some of the questions I had, but he said he could not answer them, he said he took many years of college chemistry, but forgot most of it, I asked him how can he still do all of the chemistry he does, and all of these very important tests, He said that they just add the chemicals to the machines,and perform tests, read and record results, they do not have to understand all of the reactions chemically, or what chemicals are used (again many with company trade names), or what the machines are doing or how the chemicals are reacting, they just had to know what to add when, and what buttons to push and know how to read the results and record them.

It is kind of like that with recovery and refining, you wouldn't need to understand all of the goings on chemically, you could just learn to push the right buttons, but I have always wanted to understand more (and believe it is helpful to do so), I want to find out what happens when that button is pushed, and why it happens the way it does.

Try not to get to upset because I call minerals rock.

 

[lysdexic]

The difference between smart and educated often is knowing a "thingy's" proper nomenclature. Obviously someone who is well educated in a field that demands comprehension of theory, concepts and processes beyond the grasp of most people has to be intelligent. I've found however that being educated doesn't always mean a person is smart and smart people aren't always formally educated.

I have to "translate" everything I say here because of the way I understand things (people wouldn't understand me if I called minerals rocks). I think in pictures and have never got a straight answer from anyone when I ask how their thought process works, so I still don't know if that's how everyone thinks. I often assign personality traits to things so I can remember then expand on that "personality" as I learn more (I see silver as being unpredictable in it's choice of friends and behavior and also somewhat mischievous). Hydrogen "likes" Oxygen more than it "likes" Chlorine and so forth and so on. When I explain electricity to someone that has no understanding whatsoever I compare it to plumbing and water flow, amplification being much like a small pressure switch controlling a much larger water flow valve. Currant is like the volume of water flowing and voltage is the pressure behind it. I always add that a big difference is that a "leak" could very well kill you instead of getting the floor wet.

Something you brought to mind is another interest of mine that is "waiting on parts" (all I need is a couple bags of clay). I want to build Dave Gingerly's machine shop. I would like to learn to learn to "machine" using old fashioned manual controls and methods. A CNC machinists ends up like your friend in the lab and when all the fancy equipment dies everything stops. Old fashioned machines don't have computers and depend on the skill of the operator. I've downloaded (legally) more books on foundry and machine work than I'll ever be able to read (thousands of them from late 1800's - early 1900's), so I have at my fingertips all the knowledge, wisdom and experience of those who made what we have now possible.

My driveway (dooryard) isn't minerals it's smooshed rocks.

 

[necromancer]

another great post, i do have a further question.....

how to recycle your used Acid Peroxide (A.P.) after using it to leach MLCC

i have 2 gallons of used AP, it has been slightly deluded with water & filtered well. (1 part water to 6 parts HCL)

it is purple with some white sediment. the purple comes from the leaching of the MMLC (dye) & is not a indicator of gold in this case :!:
due to the fact that Tin & HCL make Stannous Chloride (SnCl2 or tin (II) chloride) there is no gold in the MLCC i leached.

now with that being said.

how would i regenerate the AP for reuse if it does not have any copper :?:

do i simply re filter to remove all sediment & add H₂0₂ and a bubbler ?

do i need to over saturate with more HCL to remove all tin & then ad H₂0₂ & a bubbler ?

or do i ad iron to drop tin, filter ad H₂0₂ & a bubbler ?

ok thats 3 questions but you see where i need to go & any suggestions will be welcome

Thanks
Dave C.

 

[lysdexic]

Dave,
I'm only a beginner learning the chemistry of what has been called the AP (Acid Peroxide) method, so we should wait on some of the experienced members, but from the little I know...

how would i regenerate the AP for reuse if it does not have any copper :?:

The process called "AP" is actually the CuCl₂ (Copper Chloride) leaching process. If there's no copper then it isn't a CuCl solution/process. HCl isn't an oxidizing acid but it will dissolve copper, which is below Hydrogen on the reactivity series, with the help of an oxidizer (in this case H₂O₂, Hydrogen Peroxide). Metals above Hydrogen on the reactivity series can displace the Hydrogen in HCl (HCl will dissolve the metal).

CuCl solution can be regenerated with oxygen (there should be free HCl as well), the posts just before your question covers a lot of this...

do i simply re filter to remove all sediment & add H₂0₂ and a bubbler ?

I don't know if you have a Ni, Pd or what type of chloride solution, but it's not CuCl so you can't rejuvenate it... better let the others help you with the sediment.

do i need to over saturate with more HCL to remove all tin & then ad H₂0₂ & a bubbler ?

I wouldn't add any more HCl unless one of the big guys told me to and why... are there values in your solution?

or do i ad iron to drop tin, filter ad H₂0₂ & a bubbler ?

iron is used on waste CuCl leach to drop the copper after all values have been removed. It forms FeCl (anything above iron on the reactivity series that was dissolved would still be there too I believe) which is a step towards disposal of the waste solution. ...no need to add oxygen I believe.

ok thats 3 questions but you see where i need to go & any suggestions will be welcome

Thanks
Dave C.

Hope it works out for ya Dave...

Doug

 

[g_axelsson]

You are correct.
Actually that is true, if we are just talking about the pure metal being melted, and there is nothing for the metal to react chemically with in this melting process.

But in melting many metals this is normally not the case; there is something that will react chemically in the melt.


I understand that simply melting metal is not a chemical reaction.
Melting the metal can cause a chemical reaction with the metal and other components involved in the melt.

Would I be more politically correct if I said something like Melting of metals there is a chemical reaction that can take place,
where
Melting metals is a chemical reaction where metals can be oxidized or reduced (again transfer of electrons), (just like other chemical reactions we perform with metals), depending on the metal, and how it reacts with oxygen or other chemicals in the melt, we can change the chemical properties of our melt to get a desired chemical reaction, in the melting environment or with flux or both.

I may not know the best way to say some things.

I've been thinking of this on and off for a while. Still it is wrong to say that "Melting metals is a chemical reaction". When I see that I cringe just as when I see people talking about melting a metal with acid. :lol:
Yes, we often have chemical reactions going on in a melt but we also does a lot of melting where no chemical reactions happens, like when we melt our refined gold powder.
The heat and molten metal usually only accelerate the reactions that are going on even when the metal is solid. Just as copper oxidizes by only sitting in the air, heat it up and it oxidizes faster, melt it and it oxidizes even faster. Melts also lets the metal flow so we can expose fresh metal from within the melt, fresh material moves from within to the surface when molten.

I think a more correct way to express it would be something like...

When melting metals, chemical reactions can occur where metals can be oxidized or reduced depending on the metal, and how it reacts with oxygen or other chemicals in the melting environment (for example the composition of metals, gases, flux and slag). We can change the chemical properties of our melt to get a desired chemical reaction by controlling the reactions via temperature, the environment and the composition of the flux.

Some examples of how the different factors can affect the chemistry of the melt are
- Create an oxidizing or reducing atmosphere, litharge (lead oxide) can be turned into lead (reduced) by adding a carbon source to the flux.
- Lead can be turned into litharge by heating in a oven while letting in oxygen.
- By increasing or lowering the temperature some reactions are favored over others. Mercury oxide is created by heating mercury in oxygen at 350 C, mercury oxide breaks down into mercury and oxygen if heated above 500 C.
- Adding quartz (SiO₂) to the flux when smelting chalcopyrite makes the iron react with it and create an iron rich slag. The slag can be easily separated from the raw copper.

By the way, smelting is using chemical reactions in a melt to extract metals from an ore. Maybe that was what you were thinking of.

Göran