Wolosiewicz Art
Member
I’ll start by saying this is my first post, but I have been reading the forum nonstop since last fall.
I’m in the process of reading Refining Precious Metal Wastes by Hoke, I’ve watched a TON of videos on YouTube by some of our most trusted members, and I’m also an active member on the e-waste and precious metal refining Facebook group.
I started my ewaste recovery a couple years ago, but did not start refining until this spring. I’m sticking with strictly AP for now, as Nitric acid is hard to get and very expensive in my part of Canada. My first batch this spring was an experimental 100 grams of full plated pins. Soaked in AP, filtered, then dissolved in HCL and bleach. I used SMB to drop the gold, and everything went perfect. Nice golden yellow liquid, SMB turned black and settled out, all went well. It was such a small amount of gold, I filtered it, and kept the powder in the filter to process later with a bigger batch.
My second refining is where my problems began. Again, I used AP on 700 grams of full plate pins and dissolved all base metals. Once dissolved, I filtered the gold foils out, and dissolved in HCL and bleach. I used Ferrous Sulphate for this drop, as the gold bearing solution was dirty. I waited three days, and nothing settled (I had no Stannous yet…..big mistake!). I ended up boiling the solution down and adding HCL to reactivate the acid, no luck. I put some copper pipe in and cemented out any precious metals in solution (none was settled), filtered, and added the filter to the other one I was saving.
The last batch I processed yesterday was 1000 grams of partial plate pins, roughly 400 grams of miscellaneous gold plated computer parts, and the solid gold contacts from 3 electric organs. Again, I filtered the foils and gold from the AP solution, but this time I was worried the gold bearing solution would be dirty like last time, so I took my 4 filters with gold foils and put them in an HCL bath for a couple hours to clean. I filtered all the gold into one filter and put it into 600ml of new, fresh HCL. I proceeded to add bleach 10ml at a time, stirring well and waiting for any reactions to stop before adding more. It ended up taking 140ml to dissolve all the gold. With distilled water rinses through the filter, total amount sits at 1000ml.
At this point I did a stannous test, and the result was immediate and black as night, so I knew I had a good amount of gold in solution. I filtered the solution and did another stannous test…..and the test was NEGATIVE. Just minutes before, it was a strong positive, but something changed when I filtered it. I even went as far as dropping Stannous on the sludge in the filter to check it, and it was negative. This makes no sense to me.
The gold bearing solution was not the nice yellow, and was cloudy, not clear, so I knew it was going to be a dirty drop, so I used Ferrous Sulphate instead of SMB. I added six teaspoons, and the solution went from a chocolate milk brown to black, and it still sits that way.
A wonderful member of the Facebook page contacted me after my first failed drop, so we were discussing what was happening with this drop and he is thinking the amount of chlorine used is preventing the gold from dropping. He advised me to place on low heat for a couple hours and let it stand overnight for the chlorine to dissipate. I have done that, and redid the stannous test, and have very little change. Nothing has dropped out of solution, and the stannous test is such a small reaction that it would be safe to say it is no reaction.
I can’t understand why the stannous test was such a strong positive before filtering, but negative right after filtering.
I also can’t understand why cementing out my second batch didn’t work, I used thick walled copper pipe, and all it did was dissolve the copper, no sediment was produced.
I’m at a loss on the next step, and I am estimating 7-10 grams from this batch, so I don’t want to proceed and make any more mistakes without knowing where I am going wrong.
The video is the filters being washed in HCL before dissolving, and the picture is the gold bearing solution that won’t drop as of this morning.
Any help is appreciated!
I’m in the process of reading Refining Precious Metal Wastes by Hoke, I’ve watched a TON of videos on YouTube by some of our most trusted members, and I’m also an active member on the e-waste and precious metal refining Facebook group.
I started my ewaste recovery a couple years ago, but did not start refining until this spring. I’m sticking with strictly AP for now, as Nitric acid is hard to get and very expensive in my part of Canada. My first batch this spring was an experimental 100 grams of full plated pins. Soaked in AP, filtered, then dissolved in HCL and bleach. I used SMB to drop the gold, and everything went perfect. Nice golden yellow liquid, SMB turned black and settled out, all went well. It was such a small amount of gold, I filtered it, and kept the powder in the filter to process later with a bigger batch.
My second refining is where my problems began. Again, I used AP on 700 grams of full plate pins and dissolved all base metals. Once dissolved, I filtered the gold foils out, and dissolved in HCL and bleach. I used Ferrous Sulphate for this drop, as the gold bearing solution was dirty. I waited three days, and nothing settled (I had no Stannous yet…..big mistake!). I ended up boiling the solution down and adding HCL to reactivate the acid, no luck. I put some copper pipe in and cemented out any precious metals in solution (none was settled), filtered, and added the filter to the other one I was saving.
The last batch I processed yesterday was 1000 grams of partial plate pins, roughly 400 grams of miscellaneous gold plated computer parts, and the solid gold contacts from 3 electric organs. Again, I filtered the foils and gold from the AP solution, but this time I was worried the gold bearing solution would be dirty like last time, so I took my 4 filters with gold foils and put them in an HCL bath for a couple hours to clean. I filtered all the gold into one filter and put it into 600ml of new, fresh HCL. I proceeded to add bleach 10ml at a time, stirring well and waiting for any reactions to stop before adding more. It ended up taking 140ml to dissolve all the gold. With distilled water rinses through the filter, total amount sits at 1000ml.
At this point I did a stannous test, and the result was immediate and black as night, so I knew I had a good amount of gold in solution. I filtered the solution and did another stannous test…..and the test was NEGATIVE. Just minutes before, it was a strong positive, but something changed when I filtered it. I even went as far as dropping Stannous on the sludge in the filter to check it, and it was negative. This makes no sense to me.
The gold bearing solution was not the nice yellow, and was cloudy, not clear, so I knew it was going to be a dirty drop, so I used Ferrous Sulphate instead of SMB. I added six teaspoons, and the solution went from a chocolate milk brown to black, and it still sits that way.
A wonderful member of the Facebook page contacted me after my first failed drop, so we were discussing what was happening with this drop and he is thinking the amount of chlorine used is preventing the gold from dropping. He advised me to place on low heat for a couple hours and let it stand overnight for the chlorine to dissipate. I have done that, and redid the stannous test, and have very little change. Nothing has dropped out of solution, and the stannous test is such a small reaction that it would be safe to say it is no reaction.
I can’t understand why the stannous test was such a strong positive before filtering, but negative right after filtering.
I also can’t understand why cementing out my second batch didn’t work, I used thick walled copper pipe, and all it did was dissolve the copper, no sediment was produced.
I’m at a loss on the next step, and I am estimating 7-10 grams from this batch, so I don’t want to proceed and make any more mistakes without knowing where I am going wrong.
The video is the filters being washed in HCL before dissolving, and the picture is the gold bearing solution that won’t drop as of this morning.
Any help is appreciated!
