Hello, New here, think I made a mistake..

[pu_239]

I read all your post, I agree with most of what you said. I just got impatient I guess. Here is one of my major concerns. I have a feeling, the air blubbers is probably the method that would produce the best yield. One of the videos I seen, the guy said "wait about 6-7 days." That's just simply too long. Just curious about your time, You said something about 24hrs?

If you don't have the patience to wait when working in this field you will not get far.

I am pretty patient, just this gold stuff got me curious, plus I had finals coming up. SO yeah i was rushing things. I was excited, curious. You know, like christmas eve when you where a kid. But as I said, it's cool now. I will slow down, and it's better to slow down.

 

[Shark]

I read all your post, I agree with most of what you said. I just got impatient I guess. Here is one of my major concerns. I have a feeling, the air blubbers is probably the method that would produce the best yield. One of the videos I seen, the guy said "wait about 6-7 days." That's just simply too long. Just curious about your time, You said something about 24hrs?

If you don't have the patience to wait when working in this field you will not get far.

Words of wisdom, right there.

The right wording in a search is helpful, but often hard to come up with in my case. (A lack of education in the chemistry field, something I have to work hard at to overcome now) Notice the author of the most knowledgeable posts in the link. There are many very knowledgeable people on this forum and it pays well to follow their advice, in more ways than one, I read a lot from the forum and re-read things quite often, therefore I found the link in conjunction with other research I am doing already. Hope it helps.

http://goldrefiningforum.com/phpBB3/viewtopic.php?f=33&t=16744&hilit=make+poormans

 

[butcher]

pu_239,
I am glad you had success, I could not see you do the work, but from your description it sounds like a few things you should do a bit differently, as noted too much oxidizer (H2O2) will dissolve gold, and even though a small amount of heat (warm) can be beneficial, too much heat can create problems.
Heat can help to speed the reaction, but can also drive off needed components from solution, if overdone, and can cause other problems.
Hotter or faster for some things is not always better, or a good thing, we can cook the batch of cookies at very hot temperature, and cook the cookies a heck of a lot faster, with a hotter stove, but the cookies may not come out of the oven as good.

You know… It’s weird, I saw lasersteves videos, he used a lot more H2O2 than what people are recommending on this topic. I am doing my last batch right now, I didn’t add that much H2O2, just a little bit as people recommended on this topic. Yes I know that heat(too much) can ruin a reaction. My second batch, had some difficulties. I used the HCL+bleach method to dissolve the gold. I hated it, still do. I have a P100 respiratory with face shield. I could smell the Chlorine gas through it. I don’t understand, I saw Steve’s video, when he used it, the gold dissolved very quickly. For me it’s taking hours, up to 6-12 if not longer.

I filtered out whatever dissolved, and I had the filter paper with gold and some impurities. I crashed out the gold in the AuCl4- solution. The filter paper and impurities, I just simply added some NaNO3 + HCl, and heated it up. I never made “poor mans aqua regia” my plan was just to make my own HNO3. I have the NaNO3, and sulfuric acid, was going to distill them together to make NO3. Still haven’t put the pump together for the condenser.
The Solution I made to dissolve the filter paper and gold it worked for the most part. I just need to know the ratios. I filtered off that stuff and crashed out that AuCl4- as well.

I had this “waste beaker” that had gold stuff in it, and a filter paper with the gold that didn’t filter(dissolve). So I put all that stuff in some HCl and Chlorox, hoping it does dissolve it all. I have it in a erlenemeyer flask topped off with a funnel to limit evaporation and gas production. If that doesn’t work I will just evaporate off whatever Cl2 gas can be produced. Check the pH and run the solution through aqua regia.

I am running the AP in 50 degree’s C right now. That what was recommended by Steve(well a link he posted).
I let the gold settle and I tried to decant it, I saw little spots of gold in the solution still, not settled. I see some floating on top as well. They are very tiny. I decanted the solution in to a smaller beaker and I have it on the hot plate which is pretty low. I read from steve that heating it will help the gold People talked about “dissolved gold” I saw the reaction and see how it can be dissolved. So I know I have some gold in my CuCl2 solution. I crashed out the copper with some aluminum foil. I plan to filter out the copper. Now I have a solution with Al ions. I plan to crash that out with some NaOH. Filter it, then I should have a solution of mostly AuCl4-. Then I can crash that out with some SMB.

settle. I see little black spots on the bottom just from the solution that the gold was in.

I did purchase Steve’s videos last night, I bought 2 of them. The one for the Ap method, and Palladium and Rhodium from catalytic converters.
People say “Use the search function” I do, and you know what pops up? 500 replies to 1 topic. Yet the topic title isn’t even what I am looking for.

I guess my 2 real questions are, "What are the ratios for poorman's aqua regia?(I did try searching).

pu_239,
From reading your post above it sounds like you have a lot to learn about chemistry.
I see many mistakes in your thinking of how things work that will cause you to loose most of your gold, I suggest spending time in study, to learn how things really work, before dissolving much gold.

Copper metal will cement gold from solution, aluminum will replace all metals below it (see the reactivity series of metals), NaOH will form oxides and hydroxides of metals and precipitate them out of solution, although at a slightly different range of pH depending on the metal, but note the pH is hard to control, and most of the metals overlap at which pH the range they will come out of solution.

"People talked about “dissolved gold” I saw the reaction and see how it can be dissolved. So I know I have some gold in my CuCl2 solution. I crashed out the copper with some aluminum foil. I plan to filter out the copper. Now I have a solution with Al ions. I plan to crash that out with some NaOH. Filter it, then I should have a solution of mostly AuCl4-. Then I can crash that out with some SMB."

The above quote sounds like a good way and make a mess. it will not work as you think it does.

Maybe you are using too much bleach, (bleach will make saltwater out of your acid), the hypochlorite is a basic solution mixed with HCl acid produces salt water, this may be the reason your having trouble dissolving your gold, it may also be the cause of the heavy clouds of chlorine gas you had been smelling inside your respirator, without knowing what, or how you are doing these reactions it is hard to give advice, but it sounds like the best advice we can give is just spend the time to study.

 

[Pantherlikher]

Everything said to this point is useless since you "smelled Chlorine". This tells me you are no chemist with no knowledge of setting up a "safe" environment to work in.

STOP please... Set everything aside and learn the right way. Please. You hurt not only yourself, but anyone or anything around you. Permanent damage can result.

Chemical back grounded people would think before acting. Gee, an acid and a basic does what? HCL+ Bleach...

B.S.
... There is no helping the all knowing...

 

[pu_239]

pu_239,
I am glad you had success, I could not see you do the work, but from your description it sounds like a few things you should do a bit differently, as noted too much oxidizer (H2O2) will dissolve gold, and even though a small amount of heat (warm) can be beneficial, too much heat can create problems.
Heat can help to speed the reaction, but can also drive off needed components from solution, if overdone, and can cause other problems.
Hotter or faster for some things is not always better, or a good thing, we can cook the batch of cookies at very hot temperature, and cook the cookies a heck of a lot faster, with a hotter stove, but the cookies may not come out of the oven as good.

You know… It’s weird, I saw lasersteves videos, he used a lot more H2O2 than what people are recommending on this topic. I am doing my last batch right now, I didn’t add that much H2O2, just a little bit as people recommended on this topic. Yes I know that heat(too much) can ruin a reaction. My second batch, had some difficulties. I used the HCL+bleach method to dissolve the gold. I hated it, still do. I have a P100 respiratory with face shield. I could smell the Chlorine gas through it. I don’t understand, I saw Steve’s video, when he used it, the gold dissolved very quickly. For me it’s taking hours, up to 6-12 if not longer.

I filtered out whatever dissolved, and I had the filter paper with gold and some impurities. I crashed out the gold in the AuCl4- solution. The filter paper and impurities, I just simply added some NaNO3 + HCl, and heated it up. I never made “poor mans aqua regia” my plan was just to make my own HNO3. I have the NaNO3, and sulfuric acid, was going to distill them together to make NO3. Still haven’t put the pump together for the condenser.
The Solution I made to dissolve the filter paper and gold it worked for the most part. I just need to know the ratios. I filtered off that stuff and crashed out that AuCl4- as well.

I had this “waste beaker” that had gold stuff in it, and a filter paper with the gold that didn’t filter(dissolve). So I put all that stuff in some HCl and Chlorox, hoping it does dissolve it all. I have it in a erlenemeyer flask topped off with a funnel to limit evaporation and gas production. If that doesn’t work I will just evaporate off whatever Cl2 gas can be produced. Check the pH and run the solution through aqua regia.

I am running the AP in 50 degree’s C right now. That what was recommended by Steve(well a link he posted).
I let the gold settle and I tried to decant it, I saw little spots of gold in the solution still, not settled. I see some floating on top as well. They are very tiny. I decanted the solution in to a smaller beaker and I have it on the hot plate which is pretty low. I read from steve that heating it will help the gold People talked about “dissolved gold” I saw the reaction and see how it can be dissolved. So I know I have some gold in my CuCl2 solution. I crashed out the copper with some aluminum foil. I plan to filter out the copper. Now I have a solution with Al ions. I plan to crash that out with some NaOH. Filter it, then I should have a solution of mostly AuCl4-. Then I can crash that out with some SMB.

settle. I see little black spots on the bottom just from the solution that the gold was in.

I did purchase Steve’s videos last night, I bought 2 of them. The one for the Ap method, and Palladium and Rhodium from catalytic converters.
People say “Use the search function” I do, and you know what pops up? 500 replies to 1 topic. Yet the topic title isn’t even what I am looking for.

I guess my 2 real questions are, "What are the ratios for poorman's aqua regia?(I did try searching).

pu_239,
From reading your post above it sounds like you have a lot to learn about chemistry.
I see many mistakes in your thinking of how things work that will cause you to loose most of your gold, I suggest spending time in study, to learn how things really work, before dissolving much gold.

Copper metal will cement gold from solution, aluminum will replace all metals below it (see the reactivity series of metals), NaOH will form oxides and hydroxides of metals and precipitate them out of solution, although at a slightly different range of pH depending on the metal, but note the pH is hard to control, and most of the metals overlap at which pH the range they will come out of solution.

"People talked about “dissolved gold” I saw the reaction and see how it can be dissolved. So I know I have some gold in my CuCl2 solution. I crashed out the copper with some aluminum foil. I plan to filter out the copper. Now I have a solution with Al ions. I plan to crash that out with some NaOH. Filter it, then I should have a solution of mostly AuCl4-. Then I can crash that out with some SMB."

The above quote sounds like a good way and make a mess. it will not work as you think it does.

Maybe you are using too much bleach, (bleach will make saltwater out of your acid), the hypochlorite is a basic solution mixed with HCl acid produces salt water, this may be the reason your having trouble dissolving your gold, it may also be the cause of the heavy clouds of chlorine gas you had been smelling inside your respirator, without knowing what, or how you are doing these reactions it is hard to give advice, but it sounds like the best advice we can give is just spend the time to study.

This chemistry, is just off the top of my head of what i remember, I haven't written out the reactions or made any flow charts or anything. SO I agree, some reactions maybe off as I think. I don't understand what you're saying about the pH range of the metals. You can use ammonia or acetic acid to help control the pH. (I also just received my pH meter). I have previously separated many metals in solution. As I previously mentioned one of our biggest lab projects was to get metals out of solution, we had a list of "what might be in it" and we separated them and identified what was in the solution or not. This was the list, Ag+, Hg2^2+, Pb2+, Hg^2+, Bi^3+, Cu^2+,Ni^2+, Mn^2+, Fe^3+, Al^3+, Ba^3+, Sr^3+, Sr^3+, Ca^3+, all in 1 solution, Took 3 weeks.

As I said, I do agree some reactions may be off, didn't think them through or write them out(as of yet). But the separation of what i said above with the copper and aluminum, as you know it will work for the most part, There might be other metals I didn't consider. But the general procedure is correct It's all about solubility and redox.

Assuming a solution of just CuCl2(aq). Crash out the copper with Al(s).
3Cu2+ + 2Al(s) -------> 3Cu(s) + 2Al3+
Filter and wash the Cu(s).

Now you just have a solution of Al3+ + Cl-
crash out the Al3+You can add some Na(s) easy to get with electrolysis or just buy it.

3Na(s) + Al3+ -------> Al(s) + 3Na3+

Filter out aluminum, now we just have a solution of NaCl(aq). You recovered Aluminum which has value, and copper(which has more value). Final solution and you also have easy waste disposal, down the sink.

 

[Palladium]

To live in the world of academia!

 

[pu_239]

Everything said to this point is useless since you "smelled Chlorine". This tells me you are no chemist with no knowledge of setting up a "safe" environment to work in.

STOP please... Set everything aside and learn the right way. Please. You hurt not only yourself, but anyone or anything around you. Permanent damage can result.

Chemical back grounded people would think before acting. Gee, an acid and a basic does what? HCL+ Bleach...

B.S.
... There is no helping the all knowing...

I guess you should tell LaserzSteve to stop too, in his CuCl2 solution he said he smelled a bit of chlorine. OCl- is not a base, it's a reducing agent. Safe environment? I should add more chlorine according to some of the top members on here, and "OPEN MY WINDOWS" come on... I am doing this out side with a mask on.

I was going to use aqua regia, but, where did I hear about the HCl-Cl method? (here)

I was going to do these reaction my way. I did the A.P. method a bit modified, doing the way I thought was best. It worked out okay, no problems. I do see it's an art forum on "TECHNIQUE" But in terms of chemistry, no.

2nd batch, i followed the AP method more carefully as specified. That's when I smelled the chlorine gas. My first reaction, I did it with HCl-Cl my way, the reaction took a long time, but it was okay. Then I see members on here using more chlorine, and we know the result.

I heard of the "poor mans aqua regia" on here, and that didn't work out to well either, it was okay, but, not good enough. When I first heard about all this gold recovery/refining. My thought was it would be best to use the A.R. method. Assuming the A.R. method is cutting the fingers off and just dumping them in to aqua regia and going from there. Then i started to hear about the A.P. method, just don't like it. I am pretty sure it was developed for people with out a chemical background and a cheap way to do it. I honestly never done any form of chemistry like the A.P. method, honestly it doesn't make much sense to me.
I told my professors(present and past) about what i was going to do. They all said pretty much the same thing, "oh you're going to use aqua regia" They just told me about the NO gas(which i am aware of). We talked about waste disposal, safety, things of that sort, checked on the city permissible limits of Some of the gases produced, etc.

I go around watching videos, reading topics here and there, i see "you add about half a cup of that, 2 cups of that, and a few drop of this." Just no... that's wasteful, no precision. I am just going to finish this batch and do it my way. The way that makes sense to me, calculate my % yield of what i recovered. I am sure I lost some, so i'll add 5% so the chemcial reactions take place. So I know roughly how much gold is in a certain mass of memory cards and do the math for "ALL THE REACTIONS" from there. So it's not wasteful, so it's legit, so it's clean. Measure things out correctly, have the proper concentrations, etc.

The only good thing i learned is the possibility of dissolving Au in to the CuCl2 solution. I honestly have no problem with that, I can just extract it. No big deal. The people have also helped me, to identify things, of where I might be losing some gold. But with the chemical processes, no. They're just making it worse for me honestly in that sense.

I did use Less H2O2, on this batch I have running. It has been running since 2pm. I barely see any progress, When I did it my way, it was done in about 3-4hrs. just so you know.

ETA: I remember one time in lab, my teacher put an anode and a cathode in a solution.He was teaching something about electrochemical(there was something funky about Cl2). He said, "You smell that? It smells like pool? It's chlorine gas). Toxicity is based on exposure limits, and strength. The more you're exposed to a gas, the more likely it will give you problems. Or a high concentration will also give you problems. That's what MSDS is for.

MSDS: Inhalation.
Overexposure to concentrations moderately above the TLV of 1 ppm irritates
the eyes and respiratory tract. Very brief exposure to a concentration of 1000 ppm may
be fatal. Acts as an asphyxiant at high concentrations. Inhalation of high concentrations
(e.g., greater than 15 ppm) causes choking, coughing, burning of the throat, and severe
irritation of the upper respiratory tract; additionally, pulmonary edema, bronchitis, and
pneumonitis may result. Lack of oxygen can kill.

 

[g_axelsson]

Welcome pu_239,

if you want to make a profit with small lots, you need to get e-scrap for free or almost for free. If you don't consider the time spent and the lab ware, you will often go +/- zero, if you pay what the large refineries pay and have the PMs for the net price.

HCl alone will not dissolve copper. Look for the threads about CuCl2 leach.

As far as possible we never boil PM containing solutions. If you have to, you need some kind of reflux to avoid loss.

Being a chemist will make a lot of things easier for you, but chemistry makes only 10% of the art. You can't fill a bottle, that is already full, so expect to be knowing nothing. Download Hoke, read and live it. Search for the advices given to new members.

You have found an extraordinary place, where you will find all your questions already answered. This forum is full of people, who has done this a half lifetime professionally, full of chemists, physicists, engineers and impressive and ingenious autodidacts. If you understand this quickly, you have found a goldmine of information and helpful people.

Beggin your pardon sir, but HCl will dissolve copper all by it self. I have done it many times.
I add only my air hose.... I no longer add anything else.

The HCl is not dissolving the copper, it is the CuCl₂ that dissolves the copper. The HCl and oxygen from the air is transforming the CuCl into CuCl₂ again.

You kick start the reaction with a bit of H₂O₂ to create copper oxide that can be dissolved by the HCl to create CuCl₂. Or you just use some of the CuCl₂ from your last batch. You can even start the reaction by just letting copper and HCl stand. There is always some copper oxide and oxygen will dissolve through the surface and refresh the leach.
Then the reactions in the bath is these two as long as you supply the air.
1. CuCl₂ + Cu -> 2 CuCl (dissolving copper)
2. 4 CuCl + 4 HCl + O₂ -> 4 CuCl₂ + 2 H₂O (regenerate the leach)
Cut off the air and the leach of copper stops when the oxygen runs out.

If you add H₂O₂ instead of an air bubbler the orp (Oxidation-Reduction potential) can easily go so high that the HCl starts to dissolve gold. This will start to cement back onto copper and redissolve as long as the orp is too high. When the orp drops the cemented gold will stay as a metal but extremely fine, easily missed in the dark copper chloride mixture.
Adding air with a bubbler keeps the orp on a modest level as there is only a finite amount of O₂ that can be dissolved in the solution.

Göran

 

[pu_239]

Welcome pu_239,

if you want to make a profit with small lots, you need to get e-scrap for free or almost for free. If you don't consider the time spent and the lab ware, you will often go +/- zero, if you pay what the large refineries pay and have the PMs for the net price.

HCl alone will not dissolve copper. Look for the threads about CuCl2 leach.

As far as possible we never boil PM containing solutions. If you have to, you need some kind of reflux to avoid loss.

Being a chemist will make a lot of things easier for you, but chemistry makes only 10% of the art. You can't fill a bottle, that is already full, so expect to be knowing nothing. Download Hoke, read and live it. Search for the advices given to new members.

You have found an extraordinary place, where you will find all your questions already answered. This forum is full of people, who has done this a half lifetime professionally, full of chemists, physicists, engineers and impressive and ingenious autodidacts. If you understand this quickly, you have found a goldmine of information and helpful people.

Beggin your pardon sir, but HCl will dissolve copper all by it self. I have done it many times.
I add only my air hose.... I no longer add anything else.

The HCl is not dissolving the copper, it is the CuCl₂ that dissolves the copper. The HCl and oxygen from the air is transforming the CuCl into CuCl₂ again.

You kick start the reaction with a bit of H₂O₂ to create copper oxide that can be dissolved by the HCl to create CuCl₂. Or you just use some of the CuCl₂ from your last batch. You can even start the reaction by just letting copper and HCl stand. There is always some copper oxide and oxygen will dissolve through the surface and refresh the leach.
Then the reactions in the bath is these two as long as you supply the air.
1. CuCl₂ + Cu -> 2 CuCl (dissolving copper)
2. 4 CuCl + 4 HCl + O₂ -> 4 CuCl₂ + 2 H₂O (regenerate the leach)
Cut off the air and the leach of copper stops when the oxygen runs out.

If you add H₂O₂ instead of an air bubbler the orp (Oxidation-Reduction potential) can easily go so high that the HCl starts to dissolve gold. This will start to cement back onto copper and redissolve as long as the orp is too high. When the orp drops the cemented gold will stay as a metal but extremely fine, easily missed in the dark copper chloride mixture.
Adding air with a bubbler keeps the orp on a modest level as there is only a finite amount of O₂ that can be dissolved in the solution.

Göran

Been a while since I did electrochem, but this is what I have.

2H+ -------> H2 = 0.00V reduced(cathode)
Cu(s)--------> Cu2+ 0.22V oxidized(anode)

Cu(s) + 2H+ ----------> H2(g) + Cu(s)
DeltaG = 0.22, The reaction is spontaneous. This is a very small number, so obviously it doesn't happen quickly, but it does occur.

 

[g_axelsson]

I guess you should tell LaserzSteve to stop too, in his CuCl2 solution he said he smelled a bit of chlorine. OCl- is not a base, it's a reducing agent. Safe environment? I should add more chlorine according to some of the top members on here, and "OPEN MY WINDOWS" come on... I am doing this out side with a mask on.

Those videos does lack some details and were made when he developed the method in the beginning. I tried that method too and added way too much peroxide and dissolved a lot of gold in my leach but then no one realized that it could dissolve gold.

The bleach people are using to dissolve gold is a 3-8% NaCLO solution with added NaOH to stabilize the solution. NaCLO is breaking down in acidic environment and releases chlorine gas. The chlorine gas raises the orp enough so the HCl can take it into solution. The end products of the breakdown can be seen as a base (NaOH) or just as HCl is consumed to release the chlorine gas. I'm guessing on the mechanism here but the end result is the same.
The gas has to be dissolved in the solution to dissolve gold, Cl₂ is a stronger oxidizer than O₂.
When you add bleach and you see the bubbling it means that you add reagents that is just lost to the air. Small additions over time to a moderate warm solution is the fastest way to do it. Too cold and it will work slow, too hot and the chlorine gas escapes too fast.

Göran

 

[solar_plasma]

Cu(s) + 2H+ ----------> H2(g) + Cu(s)

Wow, this man is able to create electrons from nothing.

 

[g_axelsson]

Welcome pu_239,

if you want to make a profit with small lots, you need to get e-scrap for free or almost for free. If you don't consider the time spent and the lab ware, you will often go +/- zero, if you pay what the large refineries pay and have the PMs for the net price.

HCl alone will not dissolve copper. Look for the threads about CuCl2 leach.

As far as possible we never boil PM containing solutions. If you have to, you need some kind of reflux to avoid loss.

Being a chemist will make a lot of things easier for you, but chemistry makes only 10% of the art. You can't fill a bottle, that is already full, so expect to be knowing nothing. Download Hoke, read and live it. Search for the advices given to new members.

You have found an extraordinary place, where you will find all your questions already answered. This forum is full of people, who has done this a half lifetime professionally, full of chemists, physicists, engineers and impressive and ingenious autodidacts. If you understand this quickly, you have found a goldmine of information and helpful people.

Beggin your pardon sir, but HCl will dissolve copper all by it self. I have done it many times.
I add only my air hose.... I no longer add anything else.

The HCl is not dissolving the copper, it is the CuCl₂ that dissolves the copper. The HCl and oxygen from the air is transforming the CuCl into CuCl₂ again.

You kick start the reaction with a bit of H₂O₂ to create copper oxide that can be dissolved by the HCl to create CuCl₂. Or you just use some of the CuCl₂ from your last batch. You can even start the reaction by just letting copper and HCl stand. There is always some copper oxide and oxygen will dissolve through the surface and refresh the leach.
Then the reactions in the bath is these two as long as you supply the air.
1. CuCl₂ + Cu -> 2 CuCl (dissolving copper)
2. 4 CuCl + 4 HCl + O₂ -> 4 CuCl₂ + 2 H₂O (regenerate the leach)
Cut off the air and the leach of copper stops when the oxygen runs out.

If you add H₂O₂ instead of an air bubbler the orp (Oxidation-Reduction potential) can easily go so high that the HCl starts to dissolve gold. This will start to cement back onto copper and redissolve as long as the orp is too high. When the orp drops the cemented gold will stay as a metal but extremely fine, easily missed in the dark copper chloride mixture.
Adding air with a bubbler keeps the orp on a modest level as there is only a finite amount of O₂ that can be dissolved in the solution.

Göran

Been a while since I did electrochem, but this is what I have.

2H+ -------> H2 = 0.00V reduced(cathode)
Cu(s)--------> Cu2+ 0.22V oxidized(anode)

Cu(s) + 2H+ ----------> H2(g) + Cu(s)
DeltaG = 0.22, The reaction is spontaneous. This is a very small number, so obviously it doesn't happen quickly, but it does occur.

I always wanted to learn more about electrochemistry but haven't had the opportunity. But it seems something is wrong with your numbers. The standard electrode potential that I find is 0.34V for that reaction.
This is one reference among many I checked. http://www.efunda.com/materials/corrosion/electrochem_list.cfm?sort=com
And it sits on the same side as gold and platinum so I think you have drawn a false conclusion.

We also have...

In the electromotive series copper lies below hydrogen and hence
is not dissolved in dilute acids with the evolution of hydrogen.
...
Although copper does not displace hydrogen from acids, it readily
dissolves in oxidizing acids (such as strong nitric acid) or in acids
plus an oxidizing agent

No reaction with HCl is mentioned on webelements either, http://webelements.com/copper/chemistry.html
Even when I found the article "Dissolution of copper scrap in hydrochloric acid" it turned out to be the copper chloride process. 8) http://onlinelibrary.wiley.com/doi/10.1002/cjce.5450490412/abstract

Results and discussion From earlier work on dilute solutions it was
evident that the rate of dissolution of copper in hydrochloric acid
was a function of acidity, copper ion concentration and oxygen
availability, with the most significant individual processes being
attack on the copper metal by cupric ions and re-oxidation of the
resultant cuprous ions by oxygen.

As I said before, your skills and experience as a chemist doesn't impress, and that must hurt as it's coming from a physicist! :mrgreen:

Göran

 

[yar]

pu_239 many members here are trying to give you guidence in what you are endeavoring to do. I gave you a linq regarding AP which should have led you to other linqs on that topic. This topic has been covered more than most and any questions you have will be answered if you just read. You are making this more difficult than it has to be.

I have no academic scuence backround beaides what I have learned through high school. Anything I have learned regarding recovery and refining has come from reading Hoke and reading here on this forum. I work in a profession where things are right or wrong, black or white, is or is not. I can not deviate from the facts that are presented to me or lives may be lost. I approach my study's here the same way and have results to prove that. If you devitae from what has been proven here time and again you will have more problems than results. I have been here almost 2 years and I don't think I have asked as many questions as you have in your short time here.

 

[Pantherlikher]

Please stop this post from continuing...

'He knows it all and is going to do it his way because it's right and by the book...According to him so please stop trying to change his mind with wrong answers and let this post die out...

B.S.

 

[solar_plasma]

Please stop this post from continuing...

'He knows it all and is going to do it his way because it's right and by the book...According to him so please stop trying to change his mind with wrong answers and let this post die out...

B.S.

Just what I thought. Rrrright! In the beginning I believed, this guy just needs some help to find the right direction. Then it got somewhat entertaining. Now his ignorant behavior gets boring, it spams the forum with misleading assumptions stated as facts and correcting seems to be waste of time. This' my last comment regarding the I-do-it MY-way-man.

 

[pu_239]

Cu(s) + 2H+ ----------> H2(g) + Cu(s)

Wow, this man is able to create electrons from nothing.

It's called reduction potential. It's redox, electron transfers..

 

[FrugalRefiner]

The equations in your attachment are balanced. Yours is not.

Dave

 

[pu_239]

Welcome pu_239,

if you want to make a profit with small lots, you need to get e-scrap for free or almost for free. If you don't consider the time spent and the lab ware, you will often go +/- zero, if you pay what the large refineries pay and have the PMs for the net price.

HCl alone will not dissolve copper. Look for the threads about CuCl2 leach.

As far as possible we never boil PM containing solutions. If you have to, you need some kind of reflux to avoid loss.

Being a chemist will make a lot of things easier for you, but chemistry makes only 10% of the art. You can't fill a bottle, that is already full, so expect to be knowing nothing. Download Hoke, read and live it. Search for the advices given to new members.

You have found an extraordinary place, where you will find all your questions already answered. This forum is full of people, who has done this a half lifetime professionally, full of chemists, physicists, engineers and impressive and ingenious autodidacts. If you understand this quickly, you have found a goldmine of information and helpful people.

Beggin your pardon sir, but HCl will dissolve copper all by it self. I have done it many times.
I add only my air hose.... I no longer add anything else.

The HCl is not dissolving the copper, it is the CuCl₂ that dissolves the copper. The HCl and oxygen from the air is transforming the CuCl into CuCl₂ again.

You kick start the reaction with a bit of H₂O₂ to create copper oxide that can be dissolved by the HCl to create CuCl₂. Or you just use some of the CuCl₂ from your last batch. You can even start the reaction by just letting copper and HCl stand. There is always some copper oxide and oxygen will dissolve through the surface and refresh the leach.
Then the reactions in the bath is these two as long as you supply the air.
1. CuCl₂ + Cu -> 2 CuCl (dissolving copper)
2. 4 CuCl + 4 HCl + O₂ -> 4 CuCl₂ + 2 H₂O (regenerate the leach)
Cut off the air and the leach of copper stops when the oxygen runs out.

If you add H₂O₂ instead of an air bubbler the orp (Oxidation-Reduction potential) can easily go so high that the HCl starts to dissolve gold. This will start to cement back onto copper and redissolve as long as the orp is too high. When the orp drops the cemented gold will stay as a metal but extremely fine, easily missed in the dark copper chloride mixture.
Adding air with a bubbler keeps the orp on a modest level as there is only a finite amount of O₂ that can be dissolved in the solution.

Göran

Been a while since I did electrochem, but this is what I have.

2H+ -------> H2 = 0.00V reduced(cathode)
Cu(s)--------> Cu2+ 0.22V oxidized(anode)

Cu(s) + 2H+ ----------> H2(g) + Cu(s)
DeltaG = 0.22, The reaction is spontaneous. This is a very small number, so obviously it doesn't happen quickly, but it does occur.

I always wanted to learn more about electrochemistry but haven't had the opportunity. But it seems something is wrong with your numbers. The standard electrode potential that I find is 0.34V for that reaction.
This is one reference among many I checked. http://www.efunda.com/materials/corrosion/electrochem_list.cfm?sort=com
And it sits on the same side as gold and platinum so I think you have drawn a false conclusion.

Göran

Okay yes, I double checked, I used the number for AgCl(s) -------> Ag+ + Cl- which is 0.22V. It's right below Cu2+ -----> Cu(s) (0.34V). The table I am using uses small print, and there is no separating between the different redox potentials. Frankly it's tough to read, the table you showed is more readable.

Using redox potentials it's "cathode - anode", reduction happens at the cathode, oxidation happens at the electrode. Easy way to remember this oxidation starts with a vowel, so does electrode. A reaction we know is spontaneous(happens automatically) is 3Cu2+ + 2Al(s) --------> 2Al3+ +3Cu(s)

Doing the half reactions
Cu2+ --------> Cu(s) = 0.34V (reduction/cathode)
Al(2) ---------- Al3+ = -1.66(oxidized/electrode)

Formula is Cathode - anode = E

0.34 - (-1.66) = 2V

In my previous example it was just a simple mistake should be 0.00V - 0.34 = -34V

We KNOW the first example Al + Cu2+ happens automatically. So spontaneous reactions have a positive value. In the Cu(s) + H+ reaction, the answer is negative. So what this means the reaction DOESN'T occur under standard conditions. So yeah i made a simple arithmetic error.

A key thing people are forgetting is temperature. Temperature does effect the solubility. "Standard" reduction potentials are at 25 degree's C at 1atm. They are under STANDARD conditions.

Here is the triangle we used before, it links everything.

It's from the chemwiki site(it's from davis), I am an author for the site as well.

If you look at the triangle, you have to use DeltaG to determine if the reaction happens automatically at a specific temperature. So it's VERY POSSIBLE that Cu(s) can dissolve in HCl based on the temperature. Solving for the temperature that it occurs at is beyond the scope of this discussion. I'll figure it out later(after finals).

SO reviewing some old material, If Delta G < 0 it happens automatically(it's called spontaneous reaction), if Ecell(what we did above using redox potentials) is a positive value it is also spontaneous, i just got confused between the two. For a more indepth lesson on the basics of electrochemistry

http://chemwiki.ucdavis.edu/Analytical_Chemistry/Electrochemistry/Basics_of_Electrochemistry

There are 2 types of cells, a galvanic cell(a battery) and a electrolytic cell(what we're intersted in). If someone chooses to get involved in electrochemistry, don't get the cells mixed up. in galvanic cell reduction happens at the cathode, in a electrolytic cell reduction happens at the anode.

 

[pu_239]

The equations in your attachment are balanced. Yours is not.

Dave

For calculating Ecell(Voltage) they don't need to be balanced. It's an intensive property. This means it doesn't matter on the amount of substance(how many moles you have(the coefficients to balance it)). A good example is density(it's a intensive property). Does the density change if I have 1 gallon, 5 galons, 1 quart, or 2liters? No, doesn't matter, the density is the same regardless of the amount you have. The only place the equation isn't balanced is in the Ecell calculation i did. Everywhere else it's balanced.

One of the reasons i didn't balance it was because it might confuse people. If you start to add coefficinces to the redox potentials.

Cu(s) -------? Cu2+ 0.34V
Al3+ -------> Al(s) = -1.66V

Balanced it would be

3Cu(s) + 2Al3+ ----------> 3Cu2+ + 2Al(s)

People will want to do this

3 x (Cu(s) -------> Cu2+ 0.34V)
2 x (Al3+ -------> Al(s) -1.66V)

multiply the volts by the coefficients which is incorrect.

 

[pu_239]

I guess you should tell LaserzSteve to stop too, in his CuCl2 solution he said he smelled a bit of chlorine. OCl- is not a base, it's a reducing agent. Safe environment? I should add more chlorine according to some of the top members on here, and "OPEN MY WINDOWS" come on... I am doing this out side with a mask on.

Those videos does lack some details and were made when he developed the method in the beginning. I tried that method too and added way too much peroxide and dissolved a lot of gold in my leach but then no one realized that it could dissolve gold.

The bleach people are using to dissolve gold is a 3-8% NaCLO solution with added NaOH to stabilize the solution. NaCLO is breaking down in acidic environment and releases chlorine gas. The chlorine gas raises the orp enough so the HCl can take it into solution. The end products of the breakdown can be seen as a base (NaOH) or just as HCl is consumed to release the chlorine gas. I'm guessing on the mechanism here but the end result is the same.
The gas has to be dissolved in the solution to dissolve gold, Cl₂ is a stronger oxidizer than O₂.
When you add bleach and you see the bubbling it means that you add reagents that is just lost to the air. Small additions over time to a moderate warm solution is the fastest way to do it. Too cold and it will work slow, too hot and the chlorine gas escapes too fast.

Göran

Okay, I came across a video that said cold helps speed up the reaction, but you're saying the opposite. It's something I have to look in to personally. Do the calculations and see what is really going on. Tips/advice like yours are beneficial to me.