Clorox Acid Experiment - Help

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Anonymous

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Hi everyone,

Since I just learned of this process from this wonderful form I performed a small scale experiment and most likely messed it up.

He goes. Started with 2 fl oz of HCL added 1 gram of copper wire clippings #16 awg - result - nothing happened - added 1 tsp of clorox
got a slight smell of clorine but still did not notice any effect on the copper,
waited 2 minutes (guess) added 1 tsp of clorox, stronger clorine smell but no noticable effect on copper, stirred solution, bubbles formed, clorine smell again, added 1 tsp of clorox, somewhat vigorous bubbles strong clorine but copper remain unchanged.

I hope that I did not boil off the clorine from my acid, is that what I did? or did I loose clorine from the clorox? I have the solution out in the shed so the chemicals are on the cool side only 45 degrees today and about 35 right now. I have the hood on so no clorine fumes build up. Does this process just take time to get started? It did not seem to in the video that I watched but that was on foils, wire my take longer - used wire because I did not want to risk any of my stuff.

Or is the HCL peroxide system better? I will experiment with that one this weekend.

thanks, Jim

Update,

Over 1 1/2 hrs have passed went out and checked on the reaction. Solution has a definate green color, filtered out and washed the pieces of
coppers the change is mass was to small for my scale to detect >.1 gram
they were not shiny anymore and now have the more orangish copper appearence of old copper. The current solution temp is 34 f still evolving clorine gas odor. I watched that video again and he dissolved 3 grams of gold in 5 mins, am I missing something? is the temp of my reaction causing the slow progress?

thanks,

Good night.

Jim
 
Jim,

As you have discovered the chemicals you choose to dissolve your metals with has a lot to do with the reaction. So does the physical form of the metal and the temperature.

In the Acid Peroxide video I used 2 parts HCl to 1 part H2O2 (hydrogen peroxide) to dissolve the copper. The gold was partially attacked, but as the copper levels in the solution increased the gold precipitated back out.

With the HCl bleach method I attack thin gold foils which had already been stripped and cleaned of the majority of the base metals.

The main idea behind most of the reactions I perform with AP is to remove the base metals, sort of a weak nitirc acid substitute without the major fumes. Granted it will dissolve gold also, albeit slowly. I use AP specifically for removing base metal and occassionally to dissolve Palladium.

The HCl-Cl mixture is well suited to dissolving thin gold foils and powder as a substitute for aqua regia. If you are working with heavy gold shot or higher PGMs AR is pretty much mandatory*.

There are exceptions to every "rule".


Steve


*= I will be demonstrating a new easier equally effective method to dissolve PGMs very soon.
 
If you doing the fingers that are still on the cut off boards you want to start with 2 parts HCl to 1 part H2O2 (hydrogen peroxide) to dissolve the copper this will leave just the gold foils which can then be dissolved with the HCl--bleach method.
 
The green color is the copper base that the gold was attached to. If you still have undisolve gold try adding a little more clorox. Yes the gold should still drop with smb. I wouldn't expect very much if any from just 3 grams of fingers though.
 
Scrap,

Ralph is on the money. The dirty foils you have are ready to go straight into the HCl-Cl. The finger boards that have not been stripped should be processed separately with the HCl-Peroxide or other method that removes the copper and leaves the foils intact. As a rule of thumb, don't mix scrap types (pins, cpus, fingers) to keep the reaction conditions as uniform as feasible. This also helps get your yield data in line for each type of scrap.

I sort all my fingers into four grades, low, mid, high, and ultra high.
Here's the breakdown on the 'grades' of e-scrap (purely arbitrary scale I devised):

  1. Low = less than 1 g per pound
  2. Mid = between 1 and 2 g per pound
  3. High = between 2 and 3 g per pound
  4. Ultra = greater 3 g per pound

Remember GIGO when working with any chemical reaction : Garbage In = Garbage Out. If you put base metals and trash in your reactions it will be in your gold when it is precipitated. The key is to strip the trash out before you dissolve the gold. This will isolate the gold for highest purity when it's finally dissolved and precipitated.

Steve
 
Scrap,

You really should wash the powder first (boiling water, boiling HCl x 3, water rinse x3), then redissolve it in HCl-Cl again, filter it until it's completely clear (with golden color- no cloudiness) and then precipitate it with another dose of SMB to get the crude off of it.

The powder never leaves the beaker it's precipitated in except when in liquid form for filtering.

Wash the second precipitation like the first. Pour off the last water wash and swirl over gentle heat until completely dry. Swirling must be continued thru the entire drying cycle to keep the gold from popping or sticking to the beaker.

Steve
 
OK to clarify. I think you went straight to HCL and bleach is what you did. Am i correct ?

Here's the way it should go. The fingers are place in a solution of HCL and peroxide. If you doing the fingers that are still on the cut off boards you want to start with 2 parts HCl to 1 part H2O2 (hydrogen peroxide) to dissolve the copper this will leave just the gold foils which can then be dissolved with the HCl--bleach method. Now by doing this you are removing the base metal the gold is plate on. The gold that is plate to the copper is relatively pure in form. See the pure gold is on top once the base is dissolved you have solid free floating gold and you have dissolved copper in the liquid solution. Then once you filter the liquid thru a stack of coffee filters (2) Pre wet with water you are left with the foils. The solution is now holding all the trash metals. Then you take the filtered foils and place them in the HCL- Clorox solution to dissolve the foils which will separate them from the very little remaining impurities in the gold. Then you can use smb to precipitate the gold which will be of the highest purity ( Not perfect but it will do for us :wink: ) . Had you just went straight to the HCL-Clorox method you would have dissolved all the impurities and you gold in the same solution. Then when you added smb the molecules would have dragged down the copper with the gold. The copper will actually precipitate the gold it'self if enough is in there.
Plated items can be reverse plated or stripped in a cell. This way all you get is the gold off. You don't have to dissolve all the material and pollute it with base metals.

Check Steve's site to learn all this. Watch the videos
http://www.goldrecovery.us
 
When dissolving metals in the electrochemical series higher than Hydrogen, Copper being just above Hydrogen in the series, there will be no apparent reaction because there are no bubbles of Hydrogen produced but the metal is going into solution none the less. Only the base metals, those below Hydrogen, reduce Hydrogen to a gas and generate those bubbles you are looking for. Think of Hydrogen as a metal that gets reduced by elements lower in the electrochemical series.
 

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