Familiarization, Karat Gold and Stannous Chloride

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So my hot plateplate finally arrived. I have reviewed so many threads on washing, I have turned plaid. There are quite a few that say hot water, cold HCl. Quite a few that say hot water, hot HCl. There are plenty that ignore the ammonium hydroxide step, but I see that it helps liberate base metals. Is there an explanation for this that I have not searched for properly? Is there something I should be looking for that I have not seen yet? I personally think that repetitive washes, hot or cold, serve to do nothing more than remove the base metals, and the order is mostly irrelevant. Can someone smack me down?

Even current posts on the subject provide no direct insight, and it leads me to say that Harold's method is where I should stay(proven). Can anyone provide reference to posts that would give me a different opinion?

Sorry for multiple questions in one post. At the rate I go, this could be months of conversation.
Shawn
 
2 simple questions.
1. 5% weight/volume of HCl from 37% Muriatic acid = 2.7ml per 100ml water ?
2. I don't want to kill my vacuum pump just yet (compressor powered with lots of soft metal). Lou states that he uses vacuum to reduce the wait. Knowing that I am beyond patient, can I gravity filter or should I just break down and buy more stuff. Remember that I am just in the exploratory phase.

A followup for upcyclist; Next batch of fingers comes out in a day or two. I plan on making a new batch of Stannous Chloride on Wednesday. I doubt I will see any difference, but if there is I will do it again and video it.

I pick up my firebricks on Friday. I will still have to carve one out, so maybe early next week there will be a speck of something shiny.

Shawn
 
Phishin_ca said:
2. I don't want to kill my vacuum pump just yet (compressor powered with lots of soft metal). Lou states that he uses vacuum to reduce the wait. Knowing that I am beyond patient, can I gravity filter or should I just break down and buy more stuff. Remember that I am just in the exploratory phase.
When I decided to get with the program and use a Buchner fliter, I found a kit on Amazon that actually included the Buchner funnel, stopper, heavy-walled filtering flask, tubing, Whatman #1 filters, and a hand pump for $70. For my small scale, the hand pump is fine for now. When it finally succumbs to the acid fumes, I can decide then if I want to buy another one or buy an electric pump.
 
Upcyclist, did you pay for that kit yet?

My wife ordered the same one for me. With expedited shipping it was supposed to arrive day before my birthday. Birthday came and went, no kit. A week later I finally got in touch with them and they hadn't even processed the order yet. I asked them to cancel the order and they agreed, apologized and refunded my debit card.

About two weeks later I ordered another kit that was about $20 more. It came the next week and I was happy. Seemed fairly well made, held good vacuum, worked fine.

A week later, the first kit shows up on the front porch. I guess they messed up again or felt guilty about messing up my birthday so they sent it for free! BUT, I'm so glad it all happened like it did. This one was a piece of junk. The glass barb for the vacuum line had an air leak where it attaches to the flask. The glaze on the inside of the funnel was about as smooth as 60 grit sandpaper (just bare porcelain in places). I tried it with my other flask and almost couldn't get the filter paper to seal. At least I got a spare hand pump out of it.

I hope I haven't scared you too much. I really hope they send you one made better than mine. They do save a lot of time.

Edit to add..pretty sure it's the same kit anyways. Same price and same company...
 
That sounds like mine, at least the rough porcelain on the funnel itself. Everything else works fine with my kit, and the only thing I need to work on is getting that funnel nice and smooth. The #1 filters have their place, though I wouldn't use them to catch precipitated gold.

Amazon is kind of a crap shoot in general, but at least it's better than fleabay. Once when I ordered some beakers, the "Fullfilled by Amazon" pickers apparently thought you could pack them loose in a box with just a layer of bubble wrap around them. I had to send back the pieces to get a refund, but at least they gave me a prepaid sticker for it. In general, I look for vendors that look like they're stateside, and established companies (like Houston Scientific, not some random drop shipper).
 
Go figure. My update to this was one month on the dot. I varied from Lou's procedure a little.
1. Twice in distilled water
2. One dilute HCl (5%w/v)
3. One normal strength
4. Twice more in distilled water. This seemed to help me get the gold to clump.
After drying the powder, I melted.

As a side note for upcylist, or anyone else who is interested. The batch of stannous chloride I started with is still giving positive results and compared to the fresh batches I have made, it seems that the reaction my have slowed slightly. Neither was instantaneous and it may have just been my desire to find a difference in milliseconds, but I am still confident using the bottle I made a month ago.
End result from 210gm of fingers;
IMG_2408.jpg


It may be tiny and imperfect, but it is mine and I am proud of it. I am going to run this same experiment on the same weight of fingers a few times and see how the results change. I don't know how to say thank you enough for teaching me how to do this. I will be donating shortly!
Shawn
 
For as tiny as it is, absolutely! Just so you know, I would not have actually tried to refine it if you had not questioned my username. Thank you, specifically. I really do mean it. The bad part is that I cant stop playing with it.
 
goldsilverpro said:
Great color but it doesn't seem big enough. That figures only $25/pound for fingers.

I felt the same way, but I also ran them as tiny batches so my losses would be higher I think. I also saved 30ml of the solution as my standard solution.
I was concerned with getting experience with the reactions on a micro scale before I wasted chemicals and materials. I still have to deal with the filters and waste, so I am sure I will find quite a bit more.

Shawn
 
Another update. The Stannous Chloride is dead.
Following Dave's suggestion of using a standard solution only when you receive a false positive, I went a step further. It is pretty quick to make up a tiny bit directly on my spot plate. I noticed an extremely slow reaction to the test with my trusty bottle and I wondered if it was caused by excess oxidizer. A shaving of lead free solder on the plate followed by a couple drops of HCl and waiting (argh), gave me a fresh batch that turned black immediately.

I am almost tempted to no longer keep any for testing and just make new in spot 12 everytime before I start work.
 
Phishin_ca said:
Another update. The Stannous Chloride is dead.
Following Dave's suggestion of using a standard solution only when you receive a false positive, I went a step further. It is pretty quick to make up a tiny bit directly on my spot plate. I noticed an extremely slow reaction to the test with my trusty bottle and I wondered if it was caused by excess oxidizer. A shaving of lead free solder on the plate followed by a couple drops of HCl and waiting (argh), gave me a fresh batch that turned black immediately.

I am almost tempted to no longer keep any for testing and just make new in spot 12 everytime before I start work.

If you read and pay attention on how to store it you would not have this problem.
 
Phishin_ca said:
The Stannous Chloride is dead.
Following Dave's suggestion of using a standard solution only when you receive a false positive,
I'm not sure I ever suggested that. I have said that I don't test my stannous as long as it's giving a positive result. I don't need to because it's obviously still working. If it gives a negative result, then I'll test the stannous to make sure the negative is valid, and not the result of oxidized stannous.

Dave
 
The stannous test solution is easy enough to make, I always leave a little bit of undissolved tin in solution, it helps it keep longer and I keep it in small bottles without a lot of air in them. The only time I ever test my stannous is when I get a negative test on my first test of the day. Other than that, every time you use it is a test of the solution.
 

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