I have several OZ's of caps from gold filled watch bands and 70% nitric acid.How much do i need to use per OZ to get complete base metal removal.I tried reverse electrolisis and it didn't work to good so gonna try my nitric and don't want to waste it .Any info would be deeply appreciated .
GF watchband tops
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Barren Realms 007
In Remembrance
Since they are probably not all exactly alike, split them up into more than one batch then you are less likely to waste the acid.
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My approach is different for such things. This applies to gold filled items, not plated items, which are generally much better processed by stripping. That doesn't work all that well for gold filled, unless you strip by cyanide, electrolytically, which is generally beyond the ability of the home shop refiner.Barren Realms 007 said:
Combine them, because spending time to sort makes no sense. Use less acid than is required, and allow them to do as they do. Those that dissolve easiest are quickly dissolved, leaving behind those that are slower. Heat the dilute nitric so it does its work fast, then decant the solution before adding more acid. The ultimate goal is to eliminate base metals, and to gather the values. Unless you are trying to make determinations of yields for particular types, there's no real benefit in keeping them separate.
Harold
Check Goldsilverpro's recent posts. I believe he wrote quite a bit about how many ML's of dilute nitric acid are needed per gram of gold as well as silver and copper for dissolution. I can't remember the thread but I believe it was in the last week. I wish I could give you a ball park but I don't really work that way. I slowly add dilute 50/50 water/nitric until the reaction stops. Check the search function....much more on this there.
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Because you have no idea of the alloy in question in most cases, that's not an answer that can be easily supplied. It also isn't a necessity. Start with a small amount of dilute nitric and heat. Take note of the amount of work done, then add more acid accordingly. It doesn't take long until you have a feel for how much is required.brjook said:
As Hoke states in her book, the novice tends to be short of patience and will over-use acids. By heating and being patient, you can wring out all of the acid's potential.
I do not recommend processing without added heat. The difference between ambient temperatures and added heat is astounding.
Harold
Ok i had three batches about 1OZ per batch of Gold filled caps from watches .I added nitric and let it work.I then heated it till no more bubbles was seen.I decanted and added more nitric and split with equal amouts of water.Oh yea I used 100 ml of nitric 70% on each batch .When the bubbleing stopped i heated and it took a while and the batch seemed to go into a runaway reaction that boiled over in one batch. I took the remaining sediment from all three batches and again added nitric and water and boiled till no bubbles was seen.No runaway this time.I then mixed up my AR 50 ml of 70% nitric and 400 ml of hcl. I added it to the sediment and it started bubbleing real good for 45 minutes or so.I tried a test bach about 15ml of the solution and added urea to remove the excess nitric.Dilluted with 4 time water and added SMB. The solution was bluegreen not yellow like i expected.I added the SMB and the SMB turned akinda red when it was mixing .No darkening of the solution till i let it set for ten fifteen minutes.Upon checking my AR solution i still had a large amout of gold flakes floating around in it.Did it just dissolve the little bit of base metals left over and not the gold I have several grams of gold in solution and don't want to screw it up .What did i do wrong or what am i seeing ?
Barren Realms 007
In Remembrance
Possibly you should have put it thru a few water washes and then a couple of ammonia washes and you might have seen a color change indicating copper still in your mix.
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That was an indication that one of two things had occured. One was that you had eliminated all of the base metal. The other is that you eliminated all of the nitric. I choose to think that's what you did.brjook said:
That's most likely because you hadn't eliminated all of the base metals. If you had any white gold caps included, pretty good chance they were on a nickel substrate. Nickel can be troublesome---it's the thing that causes the rapid overflow of a solution, which is a VERY common reaction when processing eye glass frames. All you can do is suffer through the experience until it is all dissolved. It happens only upon the solution reaching a critical temperature, at which time a beaker that is only 10% full can rapidly foam over. I used to control the reaction by adding water. Eventually the nickel is dissolved and the reaction is normal.
Here's a hint that can be very helpful when you're processing gold filled objects. The gold can be attached to the base metal by means that leave a little to be desired, at least from the perspective of the refiner. After you have dissolved all of the base metal, something you ascertain by adding a small amount of fresh diluted nitric, and bringing the material to a boil. If there's any base metal left, you'll see the reaction. If there is not, the solution will only slightly discolor (blue/green), and there will be no brown fumes. At that time the material should be well rinsed with water, then gathered in a filter. When the solids have been extracted and dried, they should be fully incinerated, along with the filter. The resulting solids are then ground in a mortar with a pestle, and then screened. Any large items that won't go through the screen are suspect---they are either base metal that escaped dissolution, or they may be solid gold. If white in color, they may also be stainless. Testing is quite important if you hope to be successful.
Once the items have been screened, they are given a wash in hot HCl, then rinsed until the rinse solution is clear. There is no need to filter, simply allow the solids to settle, so nothing but solution is poured off.
When the solids yield clear wash water, they can then be dissolved with AR, or the solvent of your choice. The resulting solution will have a wonderful yellow color, and will filter without issues.
For starters, I see no mention of testing with stannous chloride. If you haven't, you're certainly not winning any points with me. Testing is important----VERY IMPORTANT, especially when you're trying to learn.
Ok, right now I'm inclined to think that because you hadn't removed all of the base metal (the solution wouldn't have been blue/green if you had), you dissolved some of the values, but they were most likely partially, if not fully, cemented by the remaining base metals. It's very possible that not all of the liberated gold flake was dissolved, so that may account for the flakes you see in suspension. Test the solution to see if it shows positive for gold. If it does, add a small amount of copper and allow it all to cement. When the solution tests barren, you should remove the trace of copper that was added if you can, but if not, don't worry about it. Expect the cementation to be slow unless you add a lot of copper.
When the solution tests barren, add water to dilute and allow the solids to settle. Siphon off the solution (test again to see if there's any values), and rinse well. Repeat until the solution is clear of color, then add some dilute nitric and heat. Your objective, right now, is to remove the traces of base metal you left behind. When that has been addressed, pick up on the process where you rinse well, then filter and incinerate. If you follow these instructions you will recover all of the values. If you try to re-invent the wheel and go off on a tangent, that may or may not be the case.
Harold
Thank you for your wisdom Harold and a great reply.Good to hear from the pro's every now and then.I have limited abilities here so i had to make due.I broke my batches down to about a halfa OZ and 50ml of nitric and water.Boiled it till no more reaction.I then Added the same amount of acid and water and boiled it till no more base metal was left and only gold.I then used HCL/CL and dissolved the gold.I dropped with SMB and it came out great .Upon decanting the water from my dropped gold and rinsed it with water it was already sticking together.I washed with HCL (heated) and again with waterand the gold was one big clump.So i guess i done it right this time.You guys are great and i glad i found this site .Without ya'll i never would have been able to do this from trying to find out what to do on the internet.Again thank all of you on this site for your info and guidance.
I must have read Harold comment's on these principles till my eye's blur, but every time he writes them I read them twice because the principles are so DOG GONE important to success.
Old age is making it harder to see, and I am too stubborn to wear glasses, you guys making Harold write this so many times is hard on my eye’s .
Re read again what Harold wrote above, so he will not have to write it again tonight.
Help save eyesight .
Old age is making it harder to see, and I am too stubborn to wear glasses, you guys making Harold write this so many times is hard on my eye’s .
Re read again what Harold wrote above, so he will not have to write it again tonight.
Help save eyesight .
eeTHr Wrote
eeTHr
_________________
If you are new to the practice of precious metals recovery and refining, and you want to try it because you find it interesting, then you should read the Safety Section before attempting to perform any of the procedures or obtaining any of the chemicals involved.
Remember, neither the hospital nor the morgue are interesting.
Also read: Waste Treatment for the Small Refiner, by 4metals.
Be safe, and enjoy refining.
I like this!
eeTHr
_________________
If you are new to the practice of precious metals recovery and refining, and you want to try it because you find it interesting, then you should read the Safety Section before attempting to perform any of the procedures or obtaining any of the chemicals involved.
Remember, neither the hospital nor the morgue are interesting.
Also read: Waste Treatment for the Small Refiner, by 4metals.
Be safe, and enjoy refining.
I like this!
As i stated earlier how i got the gold powder.I have to say that the dish i used was not clean .It had leftovers from a few meltings.I had to almost break the crucible to get the button out .The top was smooth but had a slight discoloration on it .I tried to heat the borax off from it but it kept coming up so i let it solidify and this is what i got.
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I commented recently on the hygiene of handling refined gold. I can't think of an easier way to undo all the work of refining than to use dirty equipment--including the torch tip. If you hope to produce gold of high quality, you must maintain a sterile environment.
Harold
Harold
It's interesting that Harold specifically mentioned the torch tip.
My last melt was twice refined and the melt was looking great. There was no discoloration and nothing moving around in the flux. As I was about to turn off the torch a black speck flew off the end of the torch and landed right on top of my button.
I have left it stuck there as a reminder to myself to make sure the torch is clean EVERY time I do a melt from now on.
I had used that torch to heat the top of some filters I was incinerating a few days earlier and, apparently, had some of that material stuck on the end of the torch.
I ALWAYS make sure my glassware is clean but never gave the torch a second thought.
My last melt was twice refined and the melt was looking great. There was no discoloration and nothing moving around in the flux. As I was about to turn off the torch a black speck flew off the end of the torch and landed right on top of my button.
I have left it stuck there as a reminder to myself to make sure the torch is clean EVERY time I do a melt from now on.
I had used that torch to heat the top of some filters I was incinerating a few days earlier and, apparently, had some of that material stuck on the end of the torch.
I ALWAYS make sure my glassware is clean but never gave the torch a second thought.
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I kept two tips for the Hoke torch I used to use. One was used exclusively for melting pure gold, to ensure that nothing contaminated the heats. When it became slightly oxidized, it was cleaned with fine polishing cloth, then blown out with clean air. Needless to say, the waste that resulted from the sanding operation was sent to my waste material. There's always microscopic beads of gold on the tip after melting, if you look closely.
Under no circumstance should a dirty torch be used when melting your gold, unless you are not concerned about purity.
Harold
Under no circumstance should a dirty torch be used when melting your gold, unless you are not concerned about purity.
Harold
I am a hobbiest and enjoy what i am doing.I have a shallow pocket and make due with what i got . I have several crucible coming and will remelt the button and post another pic .Maybe that one wil get a better review.Not that i am complaining about the one i already got .Point well taken. I am getting to the point where i need to slow down and do it like ya'll say do it .I just wanted to see how it all worked and get a feel for it and i have seem to have done that .So now as stated , put it in low gear and take my time .Again thank all of you for your replys and keep,em coming.Never to old to learn .
save the button, remelting now is not the answer, you will get more materials to process and get much better at this game, later you may want to add this button to another lot and refine it.
great job on this button, now refine your technique, your getting the hang of it and now your Hooked like a gold addict.
great job on this button, now refine your technique, your getting the hang of it and now your Hooked like a gold addict.
