Micro stripping cell

[bmgold2]

I'll probably get this wrong but I think the resistance must start low and then gets higher as the gold is removed and the base metal is exposed. I watch and when the current gets to zero, I stir the parts and that usually gets it started again until there is no gold left and the current stays at zero.

That's correct, I would say.

P_max=1A*15V=15W .... I just wanted to express, that 15W could make a little amount of liquid pretty warm...just to keep in mind, not leaving it alone.

Nice little setup!

My 1 amp was not when it was at 15 volts but the small amount of pins I ran (several batches plus the hi grade ones) did raise the temperature a little according to the stick-on thermometer on the outside of the cell. I agree that it would heat up pretty fast if used for long periods of time or with many pins at a time. Although I still have more of my low grade pins to process, I haven't done that many at a time and I would never leave this little cell running without watching it. As I keep saying though, I'm still impressed with the whole process. Just seems to use much less acid than the other options to get the gold from these parts especially considering that my parts are very lightly plated. I'm looking forward to recovering the gold from this cell but at the rate I'm going it will be a long time before that happens. I'm having fun so far.

The alligator clips I am using are just the cheap ones which is one reason I did not want to dip them in the acid. The other reason is I just didn't want acid on something I was touching even if I did have gloves on.

 

[bmgold2]

After thinking about it, I thought I should mention that I am speaking as someone who has very limited quantities of rather low grade pins to process. If you have larger quantities or better grade of materials then another process like AP might be a good option. Even if it takes more acid or a longer time it may be worth it if you don't have to actually watch the cell all the time. A bucket of AP with an air bubbler could work all by itself for days or weeks without much attention needed. Use whatever method works best for your own situation.

 

[solar_plasma]

You got it, that's why it is a recommended method for especially low grade....at least when someone feels safe with using conc sulfuric. I amsure you have read about it, but just to be sure: Remember that conc sulfuric can not be filtered, it would burn the paper in a couple of seconds or a few minutes. You will decant it and dillute the last drops of acid by pouring little acid to much water in order to prevent splashing.

 

[sharkhook]

....at least when someone feels safe with using conc sulfuric.

That is the main reason behind my going slow, as well as following this post so closely, (while studying other posts as well). I have made more than enough mistakes by jumping into unknown things when I was young, this stuff requires some study, and understanding. This is my reason for going slowly, and small scale, for the learning. I can worry about having gold in hand later. I have had some of my items for over 10 years, I see no reason to rush into things now.

And Thanks to everyone for their input.

 

[bmgold2]

....at least when someone feels safe with using conc sulfuric.

That is the main reason behind my going slow, as well as following this post so closely, (while studying other posts as well). I have made more than enough mistakes by jumping into unknown things when I was young, this stuff requires some study, and understanding. This is my reason for going slowly, and small scale, for the learning. I can worry about having gold in hand later. I have had some of my items for over 10 years, I see no reason to rush into things now.

And Thanks to everyone for their input.

This is also the reason it took me so long to try this. I bought or built all of the parts (including the acid) for this cell except for the copper mesh basket when I first joined this forum back in 2008 and have just now decided to try it. Battery acid is bad enough but concentrated sulfuric acid just plain scares me. Hopefully this fear, or should we call it a healthy respect, will help keep me and others from any accidents with this useful tool. Just because my version is small doesn't make it less dangerous.

I did also read that you can't filter the concentrated sulfuric acid but it doesn't hurt to remind anyone reading this now or later about that fact. I do remember reading one post about using a fiberglass plug in a filter but diluting the acid and powder that can't be decanted off is the way I plan to do it. Add the acid slowly to the water. I think it was around 6 times as much water as you have acid.

 

[g_axelsson]

I believe that a separatory funnel is the way to go, it allows the settled gold powder to be easily drained and the rest of the acid is returned to the cell.
I think it can be used to store the acid between runs to minimize moisture absorption between runs and the settled gold is easily drained before usage of the cell.

This is only my belief, but I have put my money where my mouth is and bought one to have when I try the sulfuric cell. 8)

Göran

 

[bmgold2]

I believe that a separatory funnel is the way to go, it allows the settled gold powder to be easily drained and the rest of the acid is returned to the cell.
I think it can be used to store the acid between runs to minimize moisture absorption between runs and the settled gold is easily drained before usage of the cell.

This is only my belief, but I have put my money where my mouth is and bought one to have when I try the sulfuric cell. 8)

Göran

That should work if you can wait long enough for the powder to settle. Mine seems to take a couple days for the thick concentrated acid to clear up. Let us know how it works if/when you try it. You should only need to use the separatory funnel when you are ready to clean out the cell anyway. Somewhere on the forum I read that you don't need to clean it out until it gets real thick with powder.

 

[sharkhook]

I believe that a separatory funnel is the way to go, it allows the settled gold powder to be easily drained and the rest of the acid is returned to the cell.
I think it can be used to store the acid between runs to minimize moisture absorption between runs and the settled gold is easily drained before usage of the cell.

This is only my belief, but I have put my money where my mouth is and bought one to have when I try the sulfuric cell. 8)

Göran

That is the first time I have seen one, and I like it. Thanks for the heads up on them. A few pictures of when you get it in use would be appreciated much.

Hopefully this fear, or should we call it a healthy respect, will help keep me and others from any accidents with this useful tool. Just because my version is small doesn't make it less dangerous.

Lets call it Healthy Respect.
The use of filters with concentrated sulfuric won't work, by my understanding, (reading).

 

[solar_plasma]

AP takes long, produces lots of liquids to handle, but is harvested fastly, sulfuric cell works fast, but takes long time to harvest. So, I like AP the best on thin material with good plating and the cell, if it is with thick pieces of basemetals or poorly plated.

 

[sharkhook]

Well I finally tried a sulfuric cell today and was very pleased with the results. A small, 1 1/2 cup cell. I didn't get any pictures as I felt I needed to pay more attention to what I was doing other than getting pictures of it. I will try to get some up in the next few days. I used a power supply from a Coleman electric cooler, 13.8 volt and 5.25 amp. I ran an inline 12 volt bulb as well, worked pretty good too. The amps never went over 1.45amp while running a nice plated ring, other than that, it stayed mostly in the 1.2amp or less range. I learned quite a bit, and next run should see some better methods on my part. I just need more to work with so the next day or two should keep me busy breaking down a few materials. Heat was good too, an identical piece of glass had a temperature of 54.2 degrees empty. The cell temperature reached 57.4 at it's highest.

I don't want to disrupt this thread so I will start another as I get going better with my own cell.

Thanks to everyone for the help with this.

 

[bmgold2]

I don't want to disrupt this thread so I will start another as I get going better with my own cell.

I don't see your additions to this thread as disruption and you are welcome to post all the information you want here.

As far as my own cell goes, I have been running more stuff through it. Most of what I am processing has just a tiny bit of plating on the tips of the pieces but I did run some nicer plated pins from an old computer. I did notice that now the acid doesn't clear up anymore even with a couple days to settle out. When I pour the acid back into the cell from the little jar I store it in, the last bit does contain some powder so I can tell it is working. Usually I leave the last bit of acid, with the settled powder, in the storage jar when I run more material but it all gets stirred back up when I pour the acid back in after I finish up for the day.

The next batch of pins I have gathered up to run are some nicely plated connector pins which weigh about 9-1/2 grams so you can see that I'm still not processing large quantities. This batch will be run in many steps since I only put a very small quantity in the little basket at a time. Still, it's much faster than one at a time like I first did.

I plan to take more pictures and try to document the steps I take when I finally clean out this cell and hopefully get my first gold bead. I can't tell how much gold might be in this cell yet but I hope to wait until I'm sure I can get enough gold out of it to hold and see without a magnifying glass.

I'm not in a big rush yet since I still need to get a hotter torch unless it warms up enough to squeeze the last bit of fuel out of my oxy/acetylene torch. The longer I wait, the more gold it should contain because I keep ripping stuff apart and when I get a little pile of pins and connectors, I set up and strip the gold off them. In the process, I'm also getting a pile of steel, a bag of wire, a lot of I.C. chips, and a couple jars with screws (one with steel ones and another for S.S.) and there are still more parts on the boards that need removed like aluminum heat sinks. I expect to get more for the other metals than I get in value of gold but that's fine. I'll have no problem selling the other scrap but the gold is MINE! I won't say I will never sell any gold I get from this hobby but this should be my first bit of self-refined gold and I don't think it will be for sale until I'm gone. Now, if this first try turns out an ounce or more...Well, money talks. I'm hoping/expecting for a gram or more.

 

[sharkhook]

I don't see your additions to this thread as disruption and you are welcome to post all the information you want here.

Thanks, very much.

This has been one of those experiences in life that sticks out in my mind. Watching that gold plate go into solution and the clean pin come back out was a real thrill for me. I have been several years trying to find the right way to accomplish this and now I know. My little cell is sitting, and hasn't settled much yet. I have a few more low grade pins ready, but not quite enough to give the cell a longer test yet.

A few of the things I need to work on.

(1) I think I will keep my power supply as is for a few pictures then try to put it in some kind of container, just to neaten up some of the clutter.
(2) A better suited containers for anode and cathode storage
(3) A container for the finished pins must be large enough to hold the unfinished pins.
(4) A larger safety catch bowl for the cell to sit in, in case of accidents.
(5) A better built basket, although this one did do pretty good.

I am sure there will be other things, as I progress, but I am getting there.

 

[sharkhook]

After sitting for a few days, I have a noticeable amount of black powder in the bottom. Not a lot, but clearly noticeable sediment. Very encouraging, as I know I am on the right path to learning this procedure. Still gathering materials, in between reading.

 

[bmgold2]

After sitting for a few days, I have a noticeable amount of black powder in the bottom. Not a lot, but clearly noticeable sediment. Very encouraging, as I know I am on the right path to learning this procedure. Still gathering materials, in between reading.

It sounds like you are doing this about the same as I am. I gather up some pins and connectors and then set up and run my cell every couple days. I'm not running a lot of material since I only get a small amount of pins and other gold plated things out of each circuit board. I'm also taking other parts off the boards at the same time and separating it to eventually go to the junk yard.

I'm getting real tempted to clean up my micro cell just to see what I get from it. I know the acid can be re-concentrated to reuse it but I'm not set up to do that. I'm not real fond of playing with concentrated sulfuric acid. Hot acid I'm not sure I want to tackle. I might just start with fresh acid after I clean up this one and use the dilute acid for something else. I'm only dealing with 1/2 cup and, if I let it settle first, the amount "lost" to clean up shouldn't be much to replace.

I'll probably wait longer and see how much more material I come up with to run but I saw another thread where there was a picture of three little gold beads with a total weight of just under 1/10 gram so my estimate on 1 gram minimum was higher than I actually need to have. Of course more gold is always better but it's been 5 years or so since I started thinking about refining gold and I don't even have that first bead yet and I'm getting anxious to move on to the next step.

 

[sharkhook]

It sounds like you are doing this about the same as I am. I gather up some pins and connectors and then set up and run my cell every couple days. I'm not running a lot of material since I only get a small amount of pins and other gold plated things out of each circuit board. I'm also taking other parts off the boards at the same time and separating it to eventually go to the junk yard.

Yes, sounds like we are working along the same lines. My scrap pile is a mess now. I used to just haul everything in one lump. Now I separate about everything. The biggest thing is I had not planned on having a place just for the plastic. Fortunately, it is only a few miles to a recycling center that takes it for free. The down side (not quite the correct term for some good learning) is I spend more time reading, which is the time I used to use to haul the excess waste off.

I have plenty of room in my little cell, so for now, I will gather a few materials, and process small batch's at a time. That should help me to better understand the hands on use of the cell it's self. I still need a dish for melting, so I am not rushing to that part yet, although I am looking forward to it. I have spent some time studying the wash aspect, and will try to follow Harold's methods, as it seems to be the best standard I could find.

Good Luck!
And Thanks!

 

[Arlea]

Very interesting post..... like many here I have been reading and reading..... and a bit of amassing. As I have no real indoor space for this (PA sucks right now) I will be amassing until spring. Hopefully by then I can have enough raw materials to work with. Keep up the great posts and thank you again.

Rob

 

[bmgold2]

Yea, PA has been pretty cold recently. Looks like next week we may get above freezing.

Here's an update on what I've been doing with my micro gold stripping cell.

I left the acid settle and poured off most of the concentrated acid and then slowly poured the remaining acid along with the little bit of black powder into some water to dilute it. Then, after that settled, I filtered the powder through a coffee filter. I ended up with a little pile of powder that I scraped out with a plastic spoon.



I was also left with a lot of the powder still stuck on/in the filter but decided to wait until later to recover that. I'm still trying to get that first piece of refined gold and wanted to start with just the easy stuff. I'll recover the rest later.



Wanting to make sure I had some gold when I finish this test, I included some gold from another test of crushed I.C. chips that I had already been cleaning in nitric acid. I didn't think the little bit of powder from the cell would be enough. Might have been a bad idea but that's what I did so far.

After cleaning the powder and the gold from the I.C.'s a couple/few times with nitric acid, I took a picture of my second leaching with SSN. I think my SSN was getting weak from sitting around so long so I did add a couple drops of homemade nitric to the leach to strengthen it. I probably should have just used HCl and bleach but I had the SSN from the Gold Hunter's Test Kit I bought so I used that. It is a much cleaner and much more intense yellow than any of my previous tests. Hopefully I got most if not all of the base metals out.



I'm now on my third leach of the same material and the color is a weaker yellow but still tests very positive for gold. I am only using 2 or 3 mL for each test and the leach is getting old so it hasn't gotten it all in one batch. Each batch was left for a day or longer and heated every once in a while with a small heat gun. I've done that before with the little sample vial but each time I hold it over another container just in case it breaks. The heat gun is very small (350 Watts) and I don't hold it real close. Just enough to get the reaction going. Don't try that with a regular jar. They will crack. As they say, don't ask me how I know that. I'm sure a regular jar could be heated in a hot water bath though.



I debated about using the KD-3 indicator/precipitant from the test kit I bought but since I don't know what it is and it seems to drop about anything in the solution, I decided to order a little bit of SMB off of Ebay for this test instead of risking messing up this test with an unknown substance. It should be here next week. In the meantime, I'll continue to leach the material and then rinse the remains a couple times with water and then wait for the SMB to drop the gold.

I still haven't gotten the MAPP gas torch to melt it anyway.

P.S. I've been re-reading Hoke's book starting from the beginning and not skipping any of it. Everyone here was right, even the parts you don't think you need (like the platinum section) has some good information in it. I should have cut my filter down to fit the funnel better so I could have washed it out better and maybe gotten more powder out of it the first time. I can't wait to see what else I missed by skipping around while reading that book. Notice in my picture above of the leach bottles that they are sitting on the book I printed and bound myself from a PDF found on this forum. That took some time but was well worth doing. I've been reading it before I go to sleep each night. I'm reading slowly this time so as much of the information as possible sinks in.

 

[solar_plasma]

You can avoid losing gold to the filters until reprocessing those, if you only decant or syphone instead. Weigh the beaker before using it and write its weight onto the white window, then you can just let dry in there and weigh it. If the beaker is extremely clean, without having been touched inside and without scratches, you can easily get the powder out of it. If not, it is still better to redissolve it there with the next batch, than from incinerated filters.

 

[sharkhook]

You can avoid losing gold to the filters until reprocessing those, if you only decant or syphone instead. Weigh the beaker before using it and write its weight onto the white window, then you can just let dry in there and weigh it. If the beaker is extremely clean, without having been touched inside and without scratches, you can easily get the powder out of it. If not, it is still better to redissolve it there with the next batch, than from incinerated filters.

Nice. That had been my understanding, but was unclear if I had the understanding correct.

Looking good there also, bmgold, I haven't made it that far yet. I ran 5 more rings through mine (two were pretty worn on the plating) and a very few more lightly plated, low grade pins. I am getting a bit "itchy" myself to see how the next steps work out here. Still haven't made any pictures though.

 

[bmgold2]

I'm starting to worry I might mess this first small batch of refined gold up since I have never had any success with it before but as far as I can tell I'm doing everything as right as I can this time.

I have all the gold I plan to dissolved into my leach solution just waiting for the SMB to get here. It should be here today or tomorrow at the latest. It took 3 little batches of SSN leach (with a couple drops of poorman's nitric in each batch) to get everything in solution. I rinsed the last batch a couple times with hot water and then made up a small batch of AR for a 4th leach. That one tested negative for gold so I assume I got it all. I dumped that batch into another jar with some more I.C. chips that has been soaking for a while now. That way, just in case I missed some, I'll catch it next time. It also had more free nitric left in that one that I didn't want in this first batch.

I went out yesterday and picked up a new torch from the local Lowes store.



I've only tested this torch out using propane to avoid wasting the more expensive MAPP gas that came with it. I think this torch should be plenty hot enough for the small quantities of gold or silver I am likely to be dealing with any time soon. I had another MAPP gas torch before and this new one makes it look pretty low powered. This one is also adjustable so you don't have to use it full blast. The torch body gets ice cold when used so I'm sure it is using a lot of fuel but I was able to get a cupel glowing hot and coated with some 20 mule team borax in just a couple minutes or so.

Hopefully, in a day or two, I should have that first bead of self-refined gold I have been dreaming of for the last 5 years or so. I won't be real surprised if something goes wrong (like I blow the gold powder all over the place) but I'm trying real hard to make sure nothing goes wrong this time.

I should have another update on this very soon, good or bad. I'm not afraid to share my mistakes. I also started over again reading the Hoke book from beginning to end. This time I have been high-lighting things I think are important to make it easier to find that information later. I've also added a few notes in the margins of the book to help me understand it better.