Newbie with question(s)

[Madraykin]

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!

 

[Geo]

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.

 

[Madraykin]

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?

 

[butcher]

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.

 

[Madraykin]

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.

 

[Geo]

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.

 

[Madraykin]

Do you mean something like this?

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

 

[Geo]

exactly.

 

[Geo]

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.

 

[Madraykin]

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?

 

[goldsilverpro]

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.

 

[Madraykin]

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.

 

[nh6886]

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

 

[Madraykin]

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.

 

[Geo]

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.

 

[scrappile]

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:

 

[butcher]

unrelated but speaking of steam, how about a bicycle

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

 

[scrappile]

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,...

 

[Madraykin]

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?

 

[nickvc]

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.