# Newbie with question(s)



## Madraykin (Nov 25, 2012)

Good morning everyone. I've been collecting scrap for the past few months. What I have access to is, I believe, well worth delving into this venture. I'll be working with copper stamped, nickel-plated backplane connectors. Part by part they'd hardly be worth anyone's consideration. As I have thousands of these parts and access to more of this often scraped material, I'm beginning to think it's worth my time and effort. 

I've read Hoke. Not in its entirety, but enough to get a rudimentary understanding. Several months back I acquired Chemistry: The Central Science and have been trudging through that to augment my understanding of chemistry in general. I bought a nice set of glassware and lab equipment and have performed a few of the experiments, as time allowed, following Robert Bruce Thompson's Lab Manual. I have access to most of the tools I've seen used in the forum for melting gold. 

Asleep yet? Anyway, all that said, I feel I am ready to approach this forum in earnest to initiate some dialogue specific to my endeavors. Thus far, I have conversed briefly with samuel-a in a few PM's. He was referred to me by the gentleman of NurdRage, so here I am. I did state that I had questions, though I'm going to reserve them until after I see if I am well-received. 

Okay, just one quick question. From the material I have available, which is copper mostly that is fully coated in nickel with some gold plating on the tips, is it possible (and I think it is from what I've seen of reverse electroplating) for me to recover the copper and nickel?

Thanks all!


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## Geo (Nov 25, 2012)

if you are reverse electroplating, the base metal and most of the nickel should remain intact. if you dissolve the base metal or even the nickel barrier, your electrolyte is too diluted or the electrolyte is too warm. 

hope this helps.


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## Madraykin (Nov 27, 2012)

Lots of views and little replies. Is there something I'm not saying correctly to initiate some dialogue. My thanks to Geo for responding. Yet I'm TOTALLY new to this and very willing to take some constructive direction, I'm taking Hoke's PDF to have printed and do a good and solid read through. I will have questions and just wondering where I should post them. New topic or existing one followed by a good collection of the experts?


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## butcher (Nov 27, 2012)

Madraykin,
Welcome to the forum, Geo gave a good answer to your question so I did not see an reason to chime in, In the concentrated sulfuric stripping cell if you keep it concentrated the gold will strip from the copper, this would leave the copper in a form you could sell (or use in some other process).

Apparently you have been doing studying of the processes, when you have a question You do not understand, and cannot find an answer to in a search just ask, everyone here is very helpful and are glad to help anyone working to learn.

I normally will not start new topics myself (and rarely ask questions), I would just continue in a related topic, this can add substance to the existing discussion, and keep related information in one place, this way others learning can find answers easier to their questions, rarely are their new questions posted on the forum that have not been discussed almost to the point of exhaustion, but many times these questions can also generate new information when answered or discussed.

Welcome to the forum I think you will find this a great place to learn, and make new friends, we look forward to your participation on the forum and sharing with us what you learn also.


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## Madraykin (Nov 27, 2012)

Hey, thanks Butcher. And you are correct. Geo did answer me very succinctly and I do plan on keeping that nugget of advice in my little process notebook.

I hope I can be pardoned for starting this new thread. I'm certain the answers are here somewhere, but in my not-so-exhaustive, semi-diligent searches I have run across threads that did begin well and somehow morphed tangentially off-topic. That is not to say I did not find anything useful; I totally did. However in my novice state of mind there remain numerous particulars and that equates to needle-in-haystackedness. Had I my druthers (along with a plump trust fund) I would fly in a team of you guys to help get me started. Barring that, I surmised that by starting a new topic, I could raise a bit more awareness to my specific (yet not altogether unique) needs. In retrospect, that line of thought does seem rather silly. But enough with my lugubrious ramblings...

I'm in acquisition mode. I have perused LazerSteve's site to get familiar with what's necessary on the material side. I encountered road block #1. Pyrex dish with lead cathode OR mild steel container AS cathode. Does anyone have a good case of one over the other? Is it a matter of personal preference? Just thinking out loud here, but would a mild steel pot/vessel/container eventually be compromised from the 90% sulfuric acid electrolyte and/or current? Or will it in fact hold up just fine and even confer some unique advantages over a Pyrex dish set-up? Would it matter if the mild steel pot was teflon-coated (almost seems like an eventual contaminant-the teflon, that is)?

Again, apologies for the new thread. I meant well.


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## Geo (Nov 27, 2012)

any coating will inhibit the the cells functionality if not keep it from working completely. mild steel will work fine for either the cell or cathode but be warned, care must be taken of either to make sure it free of acid and clean and dry after each use. i havent shared this yet but now seems a good time. taking GSP's advice on using steel, i have been experimenting with steel food cans. first, the lining must be removed. this is done best by heat.i also found the best size is the 1 gallon steel containers for bulk items (i buy mixed vegetables and make soup or stew) are cheapest. i have a fire pit so heat is no problem for me. be sure to wash and dry the can after firing. steel begins to oxidize the moment it is exposed to the air.moisture accelerates the oxidation. the good thing about steel cans are, they are relatively cheap and they work great. even if you get one use from each, if the size of the lot you are processing is large enough, wouldnt a couple of dollars investment and a couple hours prep be worth it.


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## Madraykin (Nov 27, 2012)

Do you mean something like this?

http://www.colourbox.com/preview/1765880-4930-two-steel-food-cans-isolated-on-white.jpg


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## Geo (Nov 27, 2012)

exactly.


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## Geo (Nov 27, 2012)

as a side note, you mentioned recovering the nickel. nickel is very problematic in its recovery. there is alot more chemistry and processes needed to reclaim nickel of a good purity such as electro-winning. nickel in solution is very toxic. nearly every person in the world is allergic to nickel in some form.from wiki.

Toxicity
In the US, the minimal risk level of nickel and its compounds is set to 0.2 µg/m3 for inhalation during 15–364 days.[57] Nickel sulfide fume and dust are believed carcinogenic, and various other nickel compounds may be as well.[58][59] Nickel carbonyl, [Ni(CO)4], is an extremely toxic gas. The toxicity of metal carbonyls is a function of both the toxicity of the metal as well as the carbonyl's ability to give off highly toxic carbon monoxide gas, and this one is no exception; nickel carbonyl is also explosive in air.[60][61] Sensitized individuals may show an allergy to nickel, affecting their skin, also known as dermatitis. Sensitivity to nickel may also be present in patients with pompholyx. Nickel is an important cause of contact allergy, partly due to its use in jewellery intended for pierced ears.[62] Nickel allergies affecting pierced ears are often marked by itchy, red skin. Many earrings are now made nickel-free due to this problem. The amount of nickel allowed in products that come into contact with human skin is regulated by the European Union. In 2002, researchers found amounts of nickel being emitted by 1 and 2 Euro coins far in excess of those standards. This is believed due to a galvanic reaction.[63]
Nickel was voted Allergen of the Year in 2008 by the American Contact Dermatitis Society.[64]
Reports also showed that both the nickel-induced activation of hypoxia-inducible factor (HIF-1) and the up-regulation of hypoxia-inducible genes are due to depleted intracellular ascorbate levels. The addition of ascorbate to the culture medium increased the intracellular ascorbate level and reversed both the metal-induced stabilization of HIF-1- and HIF-1α-dependent gene expression.

be careful with solutions that have dissolved nickel and wear protective gear.


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## Madraykin (Nov 27, 2012)

Okay, so during a standard reverse electroplating procedure with 90+% sulfuric acid no nickel should go into solution. That is to say the acid and current will not pull the nickel off the copper as it will the gold. Just the gold goes into solution. What I'm getting from you is that it takes more than just your run-of-the-mill sulfuric cell to deplate nickel from copper. Correct?


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## goldsilverpro (Nov 27, 2012)

Nickel will dissolve slowly and, if too much dissolves, it can poison the solution and it will cease to strip gold. The hotter the solution, the faster it will dissolve. In general, the thin nickel plating underneath the gold creates no problems. The only time I had problems was when I tried to strip gold braze from inconel, a high nickel alloy. Try to keep the temperature below about 110F. Too high a temperature is always caused by too much current. A good limit is about 8 amps per gallon.

If you use food cans, I would suggest placing them in a plastic tray, just in case they spring a leak. The only time I had leaks is when I tried using a stainless beaker. I found that mild steel stands up better than stainless.


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## Madraykin (Nov 28, 2012)

That does it. I'm gonna totally salt and ice the reaction vessel, er can. So it can get too hot, but not too cold, right? I'm terrified and ecstatic all at the same time. I believe I will go back and reread those safety notes, perhaps a few times. What great guidance and support you all provide.


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## nh6886 (Nov 28, 2012)

Hi Madraykin,

I am willing to bet that you are about to get a handful of warnings about concentrated sulfuric acid and water from some of the smartest folks around! But just incase your a night owl like me and you are about to put this plan into action, please wait until you understand the risks. I have never seen the water hits sulfuric show but I hear it's like something out of Dante's inferno. I really don't mean make light of what can happen if you had a leak I just don't have an experience to compare what I've read about. I have a small sulfuric cell I built it following Lazer Steve's plans and it woks great. I use Rooto drain opener (93% H2SO4) that I purchased at an Ace Hardware. Phildreamer gave me some great advise about keeping it tightly sealed when not in use since its hygroscopic it will gather water from the air and overflow your cell.
Best of luck and stay safe.

John


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## Madraykin (Nov 28, 2012)

Let the warnings come. I welcome them. As for me actually putting this plan into action, that won't be anytime soon. I just got some new arrows for my bow and I still have to build a target for it, there's more ground to till for my herb garden and lots more research to be done before I make this happen. Rushing into things that can maim or kill me isn't as appealing to me as it once was.


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## Geo (Nov 28, 2012)

when you dilute concentrated sulfuric acid with water, an exothermic reaction occurs.when you add the acid to water slowly, the reaction can be controlled but it will still build heat quickly.when you add water to concentrated sulfuric acid, the reaction can reach temperatures that cause water to flash boil just in the area the water is in.this reaction can not be controlled and the steam pressure from the boiling water can cause "steam explosions" throwing concentrated acid in all directions.in this case less is more.one drop of water is more likely to cause a steam explosion than a cup full. on the other side of this, to add more water than the amount needed to make a steam explosion (like dumping a cup full in) may build heat so quickly and to such a high temperature to cause the vessel to fail from thermal shock. that would leave all the acid in the vessel now splashing over everything.

the best thing is to be very careful to not let water anywhere near your stripping cell unless it was built specifically for the purpose and has a sealed water jacket. even that can fail, thats why its the recommendation of the forum in general and me personally that you leave the ice and water out of your stripping cell process.

when the cell heats up, remove the material, turn off the power and let it cool down.


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## scrappile (Nov 29, 2012)

Why steam?
Only water carries such a great amount of “latent heat”. No other liquid does. What is
latent heat? The amount of heat that is required to turn all of the water in a closed
container to vapor with out actually raising the temperature of the water. All that heat
energy to boil off the water waiting to do work. A steam engine converts this heat energy
to rotary work. Steam has an expansion rate of 1700 to 1. One square foot of water at
150 psi at 366F will expand to 1700 square feet of water vapor at 0 pressure


taken from STEAM POWER 101
By Mike Brown and H. W. Gordon

Think he might mean Cubic feet, even with one drop you get 1700. :shock:


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## butcher (Nov 29, 2012)

unrelated but speaking of steam, how about a bicycle

http://flashbackfab.com/other-vintage-antique-projects/1896-roper-steam-engine-2/


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## scrappile (Nov 29, 2012)

butcher said:


> unrelated but speaking of steam, how about a bicycle
> 
> http://flashbackfab.com/other-vintage-antique-projects/1896-roper-steam-engine-2/




State of the art for the time 8) , wonder what or how they will be posting about us 120 years from now, I'm hope it will be "Thought Indexed" so I don't have to type it out,...


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## Madraykin (Dec 6, 2012)

Okay, update. I received my 98% sulfuric acid today and with a rather large hunk of lead began fearlessly (that's a lie) reverse plating my gold.

Here's what I used:

a Pyrex casserole dish, the pretty cranberry colored kind.
a hard candy thermometer
one of those 12volt/6 volt trickle chargers. I used the 12 volt setting
My lead piece was about 1/2 inch thick, 8 inches long and 1 3/4 inches wide with one end sticking up and out of the dish. Think of an "L" lying on its back.
My cathode was simply some of the nickel and gold plated copper parts draped over the opposite side of the dish.

These parts are only partially plated with gold, so it took a fair amount to turn the acid dark. Here's what I observed. The temperature never rose above 90 degree F. As I dipped my bundles in, the gold was removed in seconds, not minutes. I could see a reaction, however it was very faint, which I'm sure had something to do with so little gold. The nickel plating did not appear to be affected. I do have a good batch of really dark acid now settling for the next day or two.

I know that I will most likely have to contend with a fair amount of contamination of some sort. My lead bar could have been a bit cleaner and the parts should have been heat treated first, but in my haste, I assumed that could be dealt with on the back end, perhaps?


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## nickvc (Dec 7, 2012)

With very low grade materials it's better to run reasonable quantities and as you have access to big quantities I'd be tempted to run at least 5 kilos to 10 kilos or more. 
The reason is simple, with small amounts of gold it's easy to lose a large percentage, if you recover 2 grams of powder from your cell it's easy to lose 0.1-0.2 grams in processing with 20 grams you might still lose the same amount but the percentage loss is much less. These loses are recoverable at a later stage if you follow proper procedures but it's as easy to refine 100 grams of recovered material as 2 and your yield data should be much more accurate.
I know the urge to see some of your own refined gold but try to refrain from running small amounts when you have big quantities to recover and refine, run small trials to see if you are stripping all the gold successfully and if so keep the cell running and during down times read up on the processes that your going to use to reach your goal. When your ready to refine have the process down pat from start to finish, remember an excess of hydrochloric does no harm but an excess of oxidisers can and frequently does, use small additions and wait until all reaction ceases before adding more and always add more hydrochloric before adding oxidisers.
Don't forget the stripped material should also have a value if well rinsed that should be another income stream. 
I wish you luck with your recovery and refining and remember your golds going no where unless you throw it away.


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## Madraykin (Dec 7, 2012)

Hey nick, just wanting to make sure I am understanding you correctly.

"I know the urge to see some of your own refined gold but try to refrain from running small amounts when you have big quantities to recover and refine, run small trials to see if you are stripping all the gold successfully and if so keep the cell running"

That confuses me somewhat and I just want to make sure I'm on the same wavelength as you. You want me to refrain from running small quantities, but also run small trials. And I'm also very unclear by your references to HCL. Thank you so much for responding, but I gotta know, what part of this thread were you responding to. I'm asking with deepest humility and sincerity. 

As an addendum to my last post, it has been 24 hours, basically, since I reverse plated. I added a heretofore unencountered step in this forum of pouring of my gold-ladened sulfuric acid from its original casserole dish into a large glass jar (24 hours ago). I am not seeing any settlement nor separation at all.


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## maynman1751 (Dec 7, 2012)

Madraykin said:


> Hey nick, just wanting to make sure I am understanding you correctly.
> 
> "I know the urge to see some of your own refined gold but try to refrain from running small amounts when you have big quantities to recover and refine, run small trials to see if you are stripping all the gold successfully and if so keep the cell running"
> 
> ...


I think what Nick is trying to say is run small trials to make sure that your cell is stripping properly, but after you are satisfied that it is running correctly, run the cell continuously with larger amounts. Be careful not to overheat the cell during this process. If the cell temp reaches 100-110F, let it cool back down.
The reference to HCl is after you have recovered the gold from the cell. Remember the cell is recovery....the next step is refining.
As far as emptying your cell, you have to filter the contents through a fiberglass plug filter to filter out the gold residue. You can't just expect it to settle out. What you can do is wait for a couple days and try to decant most of the liquid part and filter the rest. It takes a lonngggg time for it to settle! You probably haven't run enough material yet to even see any gold. It takes a considerable amount of these types of materials to get much back. If this isn't right, I'm sure someone here will correct me.


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## Madraykin (Dec 7, 2012)

I have a good feeling that it is stripping properly. From my observations, parts went in with gold and, when removed, parts did not have gold. I will continue to monitor the temps, but from what I saw yesterday, it did not produce enough of a reaction to raise the temps. I'm fairly certain this was from such a tiny amount of gold per bundle of parts submerged at any one time. Yet my clear sulfuric acid did eventually get blackish if only very gradually.

As for the filtering part, still trying to wrap my head around that. Won't I leave plenty of gold in the fiberglass? I do have some of that kaolin wool and I've heard that is ideal for this filtering process. I know, I know. Use the search feature. And I will.


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## Madraykin (Dec 7, 2012)

nickvc,

I read back over your post and it makes sense now. I must have experienced some disconnect earlier with your wording. What can I say? It's been one of those days.


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## maynman1751 (Dec 7, 2012)

> Won't I leave plenty of gold in the fiberglass?


What I did was put the wad of fiberglass in HCl and start adding small amounts of bleach and dissolve the gold right out of the filter material. Then remove the filter material and rinse it well into the HCl/Cl with the dissolved gold. Heat the solution to remove excess Cl, filter through a couple coffee filters, let it cool and drop the gold. It will be very dirty and need a good washing regimen and re-refined.


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## nickvc (Dec 8, 2012)

Sorry I tried to reply last night but couldn't get a signal to reply but Maynman did an excellent job on deciphering my meaning and I'm glad to see you now understand it too.
Because the gold content is low you will need to process a considerable amount to get a decent amount of gold and the more you do if you are sure your stripping all the gold off the better the evaluation of the material about yield. 
Make sure that when your not running your cell to keep it well covered as concentrated sulphuric is very water hungry, it will absorb water from the atmosphere easily, and if the concentration drops you will start removing large quantities of base metals. If you think the acid may be losing concentration put it on to a heater and evaporate the water back out carefully, heed the warning about sulphuric been water hungry your skin/ body is mainly water!
When you have a decent amount of sludge in your cell allow it to settle, it takes time as the acid is very viscous, decant carefully wearing gloves/ gauntlets and then you have two choices, you can then put some fibre glass into a funnel and pour the sludge and acid through that to catch the particles or you can slowly, very carefully add the acid to a large volume of water to reduce the concentration and then filter it, if you don't dilute the acid it will destroy the filter.
Once you have either the glass plug or filter, rinse with water in situ first, you can transfer it to a beaker and dissolve the values using either AR or hydrochloric and bleach. Make sure you fully understand the processes before starting them and be aware of any safety issues in all processes you intend to follow.


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## Madraykin (Dec 8, 2012)

Both you and Maynman did an excellent job of explaining. Thanks for that!

At this point, since I don't have the cell permanently set up (I was just well enough equipped to perform the stripping part), I was forced to pour the 700 ml of sulfuric acid, along with stripped gold and unknown contaminants, into a large jar with a tight lid to let settle. Upon checking this morning, I did notice a slight degree of transparency at the upper end of the solution, which tells me it is beginning to settle some.

My plan is to enhance the sulfuric cell in such a way as to make it more turn key, that is to say to make it easier to work with, more stationary, simpler to decant, and so on. What I did so far, at least in my mind, is a rough draft of a rough draft of a rough draft. I will eventually get to the point of measuring everything after the procedure is standardized.

I'm hoping to recover most of the 98% sulfuric acid or as much as possible (naive on my part?). As such, it seems the kaolin plug in the funnel is the way to go. I'd like to avoid having to heat the acid to remove water where possible or be able to do so in such a way that doesn't cause me to tremble in fear each and every time. I'll keep that option open for now since I'm really not all that far along. Much more reading to do. I have Hoke's book burned to a CD and I'm making a stop by Staples to have it printed out to take with me everywhere.

I have to admit, though, that what I have accomplished thus far is rather intriguing and encouraging. It's like when I started making lye soap.


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## scrappile (Dec 8, 2012)

Just a passing thought, 

and unknown contaminants, into a large jar with a tight lid to let settle,

possible pressure could cause failure , also location if 700 ml of sulfuric acid does spill, some things to think about when you have to leave things unattended, 

the printed Hoke's is good for adding notes in the margin, 


8)


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## Madraykin (Dec 8, 2012)

Rushing to loosen lid!!!


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## Madraykin (Dec 8, 2012)

Thanks scrappile! Also placed jar in a sturdy plastic container. When I loosened the jar lid, there was a tiny puff, but just in case...


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## maynman1751 (Dec 8, 2012)

Good points scrappile! Leave the lid slightly loose to allow pressure to release and keep the jar in a catch container in case of failure. You can't be TOO CAREFUL with these acids. Always safety first!


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## scrappile (Dec 8, 2012)

Madraykin said:


> Thanks scrappile! Also placed jar in a sturdy plastic container. When I loosened the jar lid, there was a tiny puff, but just in case...




Your welcome, 8)


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## scrappile (Dec 8, 2012)

maynman1751 said:


> Good points scrappile! Leave the lid slightly loose to allow pressure to release and keep the jar in a catch container in case of failure. You can't be TOO CAREFUL with these acids. Always safety first!



Thanks, was watching that over in Confuesd about drop, and a few others that have gone astray, from a comment taken wrong --- 


Saftey First is the Golden Rule,...


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## Madraykin (Dec 9, 2012)

Tomorrow I plan on straining my gold-laden sulfuric acid through a funnel with a kaolin wool plug. I would totally be doing this today, but I have a 12 hour shift facing me in a couple hours, so there's that. One thing that concerns me is from a process of rinsing the kaolin wool plug in situ. After I pour the acid through the funnel into a large glass pickle jar that I have scrupulously clean and dried and all of the gold (we hope) is now tied up in the wool with the sulfuric acid (somewhat clearer than before) resting securely in the jar below, do I rinse the plug in the filter into the same jar with water? I know that sounds silly, but I did not see where it was clarified and I may be misunderstanding the term "in situ". Also I am assuming that the rinse material is, in fact, H2O. I promise that I'm reading Hoke, but as I'm reading very carefully, I haven't gotten to that chapter just yet. Skip ahead, you say? If need be, but somewhere in my little nugget of a brain I formed this image of me rinsing with water through the funnel with the plug into concentrated sulfuric acid that just went through and, well, not really KABOOM, but more like shatter, shatter, splash, splash, scream, and then a life of grotesque disfigurement. Ah, the gift of foresight. Just looking to clear up the finer details and provide my readers with yet another baby step on this long and arduous journey.

Thanks to all that have gotten me this far! Oh, and by the way, I've been meaning to ask this for some time now... Any refiners living presently in the state of North Carolina?


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## maynman1751 (Dec 9, 2012)

Yes, rinse with water but I wouldn't rinse into my 'good' acid. Rinse the filter into a separate container. You DO NOT want to dilute your cell acid with water. If you really wanted to reclaim your diluted rinse, you can evaporate it down to re-concentrate it. I don't feel that there is enough loss to warrant this. Just add fresh acid to your cell to adjust level. Once the filter is rinsed you can put filter in HCl-Cl to dissolve out the gold. Once dissolved carefully remove filter and rinse well into same container as gold. Heat to steaming (don't boil) and let cool. This will remove excess chlorine. Then drop with precipitant of choice. Don't expect too much drop from a small amount of material from cell. If you still don't understand....ask!

You do know not to handle the filter without hand protection. Just saying!


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## nickvc (Dec 9, 2012)

The cell isn't in Hoke but to clarify, remove your filter with the plug in, pour your concentrated sulphuric back into its container, put filter with plug in back in place and rinse with water, this saves you from having to heat your sulphuric to concentrate it again.


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## Madraykin (Dec 10, 2012)

That is clarification aplenty. I will proceed accordingly with proper precautions as advised later today. 

Now I have a real (maybe) challenge for you guys. 

I just obtained a bag full of gold "dust" that has been ablated from gold-plated parts using a class 4 YAG laser. This stuff is completely black fine particle dust, but I know for certain that it is mostly gold. It was ablated from parts comprised of nickel-plated copper plated with gold. I'm fairly certain this material has trace amounts of nickel and copper from the ablation. From what I've learned thus far, it would be best to use nitric acid to burn off the nickel and copper and then drop with SMB. Wait. I'm wanting to make certain lead isn't an issue, so H2SO4 at some point?


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## Madraykin (Dec 11, 2012)

I just filtered my gold-containing sulfuric acid through a kaolin plug. I was surprised at how well this worked, meaning my sulfuric acid came through amazingly clean and totally reusable. At this moment the funnel with the kaolin plug is being rinsed into a clean jar with tap water. 

Before I poured off the acid with the gold into the funnel, I did notice a layer on the bottom of the jar of the black gold which had settled. The rest of the sulfuric acid was still rather dark and I'm wondering if any of that was from the lead from the cell process or maybe some of the nickel or copper.

I'm going to perform a search on the ratio of HCL to ClL needed to dissolve the gold in the kaolin plug.


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## martyn111 (Dec 11, 2012)

Madraykin said:


> From what I've learned thus far, it would be best to use nitric acid to burn off the nickel and copper and then drop with SMB.



If you did as you say above you wouldn't have any gold in solution to drop with SMB. Gold will not dissolve in Nitric acid alone, therefore the resulting powders from your Nitric bath would be your gold content which you could then process either by AR or hcl / chlorax.
Look at the process you outlined as a recovery process, removing base metals,and the AR or hcl / chlorax as the refining process when you actually dissolve the gold.




Madraykin said:


> I'm going to perform a search on the ratio of HCL to ClL needed to dissolve the gold in the kaolin plug.



You can cover the powders you intend to dissolve with hcl and then add your chlorax in small increments until all the powder has dissoloved, much the same as adding the Nitric acid in AR, this way you don't add a large excess of oxidiser which you will need to dispel before you can precipitate your gold.


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## Madraykin (Dec 11, 2012)

Martyn, Yes, my goof. I'll seem a little more sensible about this once I've actually performed the steps beyond what's been done thus far.. Been combing through here reading up on the AP and the HCL-CL methods. I'd be curious to know if anyone uses either a sep funnel or a burette to add in their oxidizer drop by drop.


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## Madraykin (Dec 12, 2012)

Today I took my Kaolin plug from the funnel after running the water through the plug yesterday, dropped it into a flask, poured in 120-150 ml of HCL, swirled it around a bit and then added Clorox in 3 increments of about 20 ml each. I observed, after the final addition of the Clorox, the kaolin plug is still black with something, a color change of the solution to a yellowish-green color and some fine black particulates floating around. Here shortly I will GENTLY heat to drive off excess chlorine.


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## qst42know (Dec 12, 2012)

What were you filtering?


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## Madraykin (Dec 12, 2012)

I filtered the gold that reverse plated in the sulfuric cell.


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## qst42know (Dec 13, 2012)

It could be a small amount of insoluble silver or lead chloride. 

What kinds of material were you stripping?


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## Madraykin (Dec 13, 2012)

The material I'm stripping is nickel-plated copper. 

I can add now that after the heating yesterday, which began as gentle, but somehow reached boiling (take your eyes off for two seconds...), the solution lost it's green hue and is now primarily yellow. One odd thing to note, I placed a teflon-coated stir bar in the flack with the kaolin plug and HCL-CL solution and set it to spinning. Well, instead of spinning it danced around in the solution. I was going to remove it until I noticed it buffeting the kaolin plug and knocking the black stuff off of it and into the solution. Eventually the kaolin plug lost its cohesiveness and released just about all it was hanging onto.


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## Madraykin (Dec 13, 2012)

So I can drop gold from this HCL with oxalic acid instead of SMB? I totally have some oxalic acid and I totally don't have SMB. Sweet! Now I must do a search here for some additional posts regarding oxalic acid to know what to expect.


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## maynman1751 (Dec 13, 2012)

http://goldrefiningforum.com/phpBB3/viewtopic.php?f=49&t=16384
There are good directions here on how to use oxalic acid.


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## qst42know (Dec 13, 2012)

maynman1751 said:


> http://goldrefiningforum.com/phpBB3/viewtopic.php?f=49&t=16384
> There are good directions here on how to use oxalic acid.



Hoke describes the use of oxalic, and I have used it a few times. 

It is not a good first refine precipitant.


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## Madraykin (Dec 15, 2012)

Thanks for that link qst. I went ahead and ordered some SMB since I saw somewhere in here that it is used for an initial drop. It was cheap. I also ordered a pound of pure tin for making the stannous solution. Then I bit the bullet and bought a vacuum filtration system. Taking along my new BFF Hoke with me to work today and tomorrow.

Thanks again to everyone who has contributed to this thread. Thanks also to all who have taken the time to read here without leaving a comment, because you have posted elsewhere and I have learned from you. This forum is most excellent.


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