# Stannous chloride Colors?



## eeTHr (Jul 6, 2009)

In the forum handbook it lists stannous chloride test colors which are different than Hoke states.

The handbook says a platinum solution will show red, and Hoke says it will range from deep yellow to brown depending on strength.

The handbook has palladium as showing deep yellow to brown, and Hoke lists it as deep yellow at first then turning to blue-green.

Can someone address this basic question?

Any additional helpful hints on the use of stannous chloride would also be appreciated.

Don


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## Harold_V (Jul 6, 2009)

eeTHr said:


> In the forum handbook it lists stannous chloride test colors which are different than Hoke states.
> 
> The handbook says a platinum solution will show red, and Hoke says it will range from deep yellow to brown depending on strength.


In my years in the lab, I don't recall ever seeing a platinum reaction that was red. The best description I can offer is that it will look like coffee, but if there is precious little in solution, it can be yellow, ranging down through a deep dark brown as the solution is more concentrated. 



> The handbook has palladium as showing deep yellow to brown, and Hoke lists it as deep yellow at first then turning to blue-green.


Palladium is a bit of a chameleon. It can display all of those colors, and under very strange circumstances can be confused with a dilute gold solution. The big difference is it doesn't leave a purple stain on your spot plate (which I advise). If you have even a remote question about the presence of palladium, or if you have palladium in solution with gold and or platinum, it's wise to do a test with DMG, which is conclusive. Even traces of palladium will yield a bright canary yellow precipitate. 

There's more to consider. If you have more than one metal in solution, it often pays to add a crystal of ferrous sulfate to the test drop you have placed in your spot plate (that's why I recommend a spot plate) to precipitate the gold. You can then test the solution for the presence of other elements of concern, using stannous chloride. Gold so precipitated will come down as a fine sheet of gold, or in minute particles that are anywhere from golden color to dark brown. The resulting tests are then much easier to read. 

My advice to you is to obtain a grain or two of each of these metals and prepare standard solutions. If memory serves, Hoke provides guidelines. By doing so, you can witness the color reactions in person, so you can understand what you're seeing when you are testing an unknown solution. Testing is very important to achieving success. 

Harold


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## markqf1 (Jul 6, 2009)

Go with the photos of the q-tips that lazersteve has posted somewhere on the forum.
It's the same colors I always get for pt and pd .

pt- orange
pd- blue-green


Mark


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## eeTHr (Jul 6, 2009)

Mark;

Thanks, I'll check that out. I've been to his site before, but I think I have a slight case of info overload lately!

Since you are getting the same results consistantly, I'm wondering what the source of your solutions are? Jewelry, eScrap, ore, or what? (I'm learning by doing some eScrap.)

It looks like other things in the solution can affect the stannous results sometimes.

Don


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## eeTHr (Jul 6, 2009)

Harold;

Thank you very much.

I remember reading something somewhere awhile back (before starting to actually make some attempts at recovering/refining) about precipitating-out the gold first in a spot plate, like you just said, but I had totally forgotten about it. I think the differences in color descriptions threw me for a loop!

I was going to try to recover the metals for my standard solutions, but I can see that the probable impurities would confuse things. Especially if I make tests with different combinations and ratios of the PMs and also with some base metals, to be more able to guesstimate what's in a values solution.

I'll be getting a spot plate and DMG on my next chemical order.

Another question about stannous chloride testing solutions: There are several different formulas for making it, and whether directly with metalic tin or with dry stannous chloride, there are widely differing dilutions listed. Some with HCl only, all the way to large water dilutions. Does the higher pH of the high water dilutions make it easier to get color from less-diluted (more acid) value solutions?

Also, related to this, I read in your posts that you recommend more concentrated value solutions (I think you said because it precipitates larger particles). I read in Hoke that she recommends more diluted solutions (I think she said because the precipitation settles quicker).

What is the real scoop on both stannous chloride dilution, and also on value solution dilution, and how (or) do these two vary in relation to each other?

Don


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## markqf1 (Jul 6, 2009)

Don,
Everything you mentioned and more such as cat cons, native gold, and electronic medical scrap.
You should be in a good area to collect some native gold.

You have to work with the stannous a little bit to figure it out.
I find that when it shows a positive test on my standard gold solution, it is good to go.

LazerSteve and others have alot of info posted about this on the forum.

Mark


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## eeTHr (Jul 6, 2009)

Thanks, Mark.

I have been to the mountains, and did get a little gold there, but I haven't tried processing any of that yet as it is in storage at this time. But I will.

I have been experimenting with different dilutions a little, and I think I noticed some differences, but they weren't really accurate tests, just curious tries. It's always good to get experts' opinions, to keep from straying too far off track. And you never know when you might pick up a little jewel that's not mentioned elsewhere.

I notice that now that I have done a few solutions and precipitations that when I go back and re-read the forum that it becomes more understandable. You folks are a great help!

Don


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## lazersteve (Jul 6, 2009)

Don,

I use this formula for making stannous and I always have the same results no matter what the source of the scrap is:

1) 2 grams of pure powdered tin
2) 30 mL 32% HCl
3) Heat until fizzing begins (this takes around 10 seconds depending on your heat source)
4) Stop heating and let react uncovered until the solution clears, the solution should be colorless.
5) Store in a sealed container out of direct sunlight
6) Undissolved tin should remain in the storage vessel at all times
7) Test against known PM solution once per week or when you suspect it is not working

Here's the photos of the positive swabs and the Rhodium stannous test:








*and positive test of Rh (left vial) and Pt (right vial) in solution using heated stannous chloride:*






Steve


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## eeTHr (Jul 6, 2009)

Steve;

Awsome. Thanks a gazillion.

And I will be on your Website again soon, because I need a couple of things (and to watch some videos over again).

Don


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## eeTHr (Jul 8, 2009)

Harold;

I'm still very interested in any information about these two questions, which got bumped up the screen by some other appreciated answeres, and themselves went unanswered---



eeTHr said:


> Another question about stannous chloride testing solutions: There are several different formulas for making it, and whether directly with metalic tin or with dry stannous chloride, there are widely differing dilutions listed. Some with HCl only, all the way to large water dilutions. Does the higher pH of the high water dilutions make it easier to get color from less-diluted (more acid) value solutions?
> 
> Also, related to this, I read in your posts that you recommend more concentrated value solutions (I think you said because it precipitates larger particles). I read in Hoke that she recommends more diluted solutions (I think she said because the precipitation settles quicker).
> 
> ...



Like I said before---



eeTHr said:


> It's always good to get experts' opinions, to keep from straying too far off track. And you never know when you might pick up a little jewel that's not mentioned elsewhere.
> 
> Don




Curiosity isn't all that bad---sometimes you even learn something!

Don


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## Harold_V (Jul 8, 2009)

eeTHr said:


> Does the higher pH of the high water dilutions make it easier to get color from less-diluted (more acid) value solutions?


My experience dictated that the level of HCl made no difference. The presence of nitric, on the other hand, generally spelled either a poor reaction, or one that was temporary. It was not unusual to see a reaction develop, only to disappear. 



> I read in your posts that you recommend more concentrated value solutions (I think you said because it precipitates larger particles). I read in Hoke that she recommends more diluted solutions (I think she said because the precipitation settles quicker).
> 
> What is the real scoop on both stannous chloride dilution, and also on value solution dilution, and how (or) do these two vary in relation to each other?



It stands to reason that you will get more profound results when testing concentrated solutions. In my mind, I imagine the best case scenario being one whereby the testing solution (stannous chloride) is of such a concentration that it reacts properly, and will serve to help determine the level of concentration of values in solution. Said another way, if a trace displays equally as well as a heavy concentration, the testing solution tends to lose some of its value. You'll notice, when precipitating, as you near the end of precipitation, the reaction falls off. That's important in helping you judge the existing conditions. 

As far as concentrated solutions of values go-----there are reasons to precipitate from both dilute and concentrated. The platinum group can refuse to come down at all, and often does, from dilute solutions. In that case, the heavier the concentration, the better. I experienced complete precipitation in rare cases, but generally got only a partial. The complete occurrences were always from heavy concentrations, and took place rapidly. 

Gold is better precipitated from dilute solutions, so traces of silver will self precipitate and can be removed in filtration. Beyond that, I know of no particular benefits aside from not needing any cooling. That's assuming you precipitate with SO2. 

I'm sure you have read that silver, for reasons not well understood, will behave as gold, staying in solution, following gold in spite of it being a chloride solution. You'd expect the silver to precipitate as chloride, but that is not the case. GSP has pointed out numerous times that by diluting the solution, the silver precipitates. I found that to be true in practice. 

I had reason to work with concentrated solutions. Refining commercially, were I to dilute everything, I would have dealt with huge volumes, requiring the use of larger beakers, and more of them. By keeping my solutions concentrated, and using ice for precipitation, to provide the needed cooling, I could process several ounces of gold per liter. That may or may not be important to you. 

Because my end product received a wash in ammonium hydroxide, traces of silver chloride that may have been included were eliminated. That would be of concern for gold that was used in making white gold, or for other applications, where silver was not allowed. 



> Also, related to this, I read in your posts that you recommend more concentrated value solutions (I think you said because it precipitates larger particles). I read in Hoke that she recommends more diluted solutions (I think she said because the precipitation settles quicker).


It is not the case that fine particles settle quicker. It is more desirable that they are coarse, in which case they settle instantly. Fine precipitation often takes several hours to settle. The gold stratifies and can be observed slowly moving towards the bottom as a broad layer.

Hope this helps. 

Harold


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## eeTHr (Jul 9, 2009)

Harold;

You are _very_ helpful, indeed! Thank you!

After much reading on this forum and other sites, and the Forum Handbook and Hoke downloads, and then going back and trying to make notes and organize the information, it still leaves some "in between" questions.

You brought it all together for me on the above questions, and more, in a "big picture" kind of way. Very much appreciated.

I had noticed, when I first started doing this a several weeks ago, the purple starting to show then disappearing. I wasn't sure if it was nitric, or just too much acid in general. Then I started boiling-down my solutions---so _that's_ why it's been OK.

I get it that it's best to always make the testing solution the same, whichever formula is used.

I like to test different source materials to see what average values are in what type of stuff, and on small tests like that it's hard to get a concentrated values solutions, so I'm thinking of determining (if there exists) a formula which will be more likely to detect small trace amounts in un-diluted solutions. So this is one of the reasons I got to wondering about that, and thought it would be worth asking.

I had read where you said that when precipitating with SO2 that the gold will mysteriously drag down a tiny bit of palladium, but I didn't know about the metalic silver oddity. I did get some silvery particles which when re-disolved tested strongly for gold, and when re-precipited still looked silvery; so now I know what to try if that happens again. Once, I happened to add a lot of water into a greenish solution, and the next day the solution was blue, and there was the white powdery stuff on the bottom (that was before I read about silver, lead, and mercury chlorides, and boiling water re-disolving the lead chloride) and I was baffled. I thought I just had made a mess. I didn't expect silver, but I think there was some solder in my first solutions so it was probably mostly lead. So I should have diluted that type of solution more anyway, I just didn't know it. Glad that came up, thanks! (Also I think diluting for the silver chloride first _is_ in Hoke, but I had lost it in the swirl of information I was trying to digest in order to just get my feet wet with this.) Recently I've been soaking anything with solder on it overnight in HCl, then boiling it the next day, to clean the solder off first, and that seems to be working pretty well.

And I don't remember anything at all about the SO2 generating lots of heat, and lately I've been thinking of using it, so thank you very much for including that. 

And thanks for all your additional detailed discriptions---that does really help a lot. Every time something "different" happens in a reaction, I think "holy cow, what's _that_, what did I just _do_? So now I won't be so baffled!

Don


Changed "the gold will mysteriously drag down a tiny bit of _platinum_" to "the gold will mysteriously drag down a tiny bit of _palladium_"


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## Harold_V (Jul 10, 2009)

Don,
Heat from precipitation is pretty much a non issue unless you have heavily concentrated solutions. What you'll discover if you do use SO2 and have too much gold in solution is that it hits a wall and won't precipitate. It happened to me countless times when I'd re-refine my gold. I started with roughly 18 ounces of gold in a liter, to which I'd add three liters of ice. By the time the gold was down, the iced solution was hot enough to be steaming----and often wouldn't precipitate the last traces of gold. I learned that adding just a little more ice did the trick. The solution was saturated with SO2, so the moment temperature dropped a little the gold came down. It was visibly obvious.

If you dissolve SMB in water before application, and you have gold concentration quite low (3 oz/liter or less), I don't think you'll even detect a change in temperature when you precipitate. 

Regards any of your testing solutions, be they standard solutions or any of the indicator solutions, yes, by all means, always make them the same way. Also, test your stannous chloride against your standard gold solution regularly. As it ages and weakens, the reaction diminishes, eventually coming to a full stop. 

Glad to hear some of the things I mentioned helped. That's the name of the game here, to assist others. 

Harold


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## goldsilverpro (Jul 10, 2009)

Early on, I bought the traditional mossy tin and made the stannous chloride solution as per the instructions I found - probably from Hoke. I mainly used it for PGMs since I had developed reliable visual indicators for the presence of gold in most types of solutions. As a result, it would sit around between uses and I often had to make a fresh batch when I needed it. I didn't like having to do this.

Later on, I stopped making the solution altogether. I just put a drop or two of the acid solution I was testing, from an eyedropper, on a piece of filter paper. The filter paper I chose was such that the drops generally stayed in one spot and didn't spread (wick) quickly. I then immediately added a couple of stannous chloride crystals from the tip of my pocket knife and finally added a drop of water, if needed. The colors were always vivid. I found that when there were two, or more, PMs, say, Au and Pt, the various colors spread slowly and appeared separated in fairly distinct rings. Sort of like paper chromatography. The type of filter paper I used was very important. I used S&S 596 paper, but I think they stopped making it. Some of the slower Whatman papers worked well. Coffee filters don't work well at all for this. I always thought it would be neat to use paper chromatography techniques (vertical paper strips with the bottom tip in the solution) for this but never got around to it.

I'm not suggesting that you use this. Just showing how I did it.


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## eeTHr (Jul 10, 2009)

Harold;

Starting with eScrap, I don't think I'll have any teen oz/liter solutions any time soon, but all your points are helpful. Hoke mentioned that warmer solutions precipitate better, as in disolving the SMB in warm water instead of cool. But with your icing experience, it appears that there is actually a sweet spot temperature-wise that is optimum. Very good to know. Thanks again!


GSP;

Visual indicators for gold in solutions? I've never heard of anything like that. I'd be very interested in hearing how that works!

I thought about using the stannous chloride crystals directly, but in a spot plate (I use a white plastic measuring spoon as I don't have a regular spot plate yet), but I never got around to trying it. I've read where some people use a small copperas crystal like that, and I tried that and it worked (and as Harold said above, stannous also helps for further testing of the solution, with the gold removed). I'll try the crystals on both paper and spot spoon next time.

I too like the benefit of the multiple colors on paper. I only have coffee filters now, and I do notice that they are not as sensitive as the spot plate type of test. Hoke mentioned the alternate of blotting paper, but I don't think they even make that anymore. So I'm looking in the meanwhile for a better paper. Maybe pencil drawing paper? Or what they call construction or craft paper?

I also notice that the coffee filters seem to give a more defined and darker edge-line if the values solution has dried or nearly dried, and also there is a different pattern if you do the opposite and put the stannous chloride on the paper first. I happened to let a drop of values solution dry once, and tried the reverse wet and dry, but no multiple testing to verify the results yet. I thought about making up some "stannous papers" ahead of time to see if that would work, but I'm not sure how long they would last even in a sealed bottle. Maybe since they were dry they would last awhile. I was figuring on small rounds or squares, but strips would probably be easier to read or even put side-by-side to compare. So I'll try this next time I get a chance.

Thank you very much.

Don


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## goldsilverpro (Jul 14, 2009)

> Visual indicators for gold in solutions? I've never heard of anything like that. I'd be very interested in hearing how that works!


First of all, I'm talking about determining whether any gold was left in an aqua regia solution after precipitating the gold with sodium sulfite. I most always dropped the gold in a white plastic bucket. I rarely got rid of the base metals before dissolving the gold. I final pured the gold in the melt, when necessary.

(1) When you whip up the solution with a sir rod, you get some foam. If the foam is whitish, with no yellow, there is essentially no gold present. Even with Cu or Ni, the foam will be whitish.
(2) Using good lighting, tilt the bucket slightly and quickly look for a yellow film on the bucket. Only gold will produce this film - iron won't. 
(3) This is hard to explain. The last little bit of gold usually came down finer than the rest. When the copper and/or nickel solution is mixed with a little gold powder, in the absence of any yellow gold solution, it forms a very distinctive color that is hard to miss. Just a trace of gold changes the color.
4) Looking down into a beaker of solution, a very small amount of yellow gold solution will show up at the surface edge of the solution, even in a dark green solution. Using good lighting a a piece of white paper behind it helps it a lot to be able to see this. Here again, tilting the beaker will provide a temporary yellow film on the glass - use the white paper. Iron will do the same thing, but the yellow color is different - less yellow, if that makes any sense.

I used a combination of these each time. Number (3) was always very reliable.


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## eeTHr (Jul 18, 2009)

GSP;

Wow. I've noticed some characteristics similar to what you just described, and wondered about them, but I don't have enough experience yet to relate them to any particular result.

I'm going to be paying more attention now, for sure! I guess it's time to start making notes each time.

I had to take a break from it, to make a fume hood. I finished it today, so I'll be trying it out soon, and also trying some of the tests I mentioned in my posts above.

Thanks a million!

Don


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## goldsilverpro (Jul 18, 2009)

I should also mention the smell when using a sulfite to drop the gold - SMB, sodium sulfite, etc. After stirring well, when you have gold left in the solution, you will have little or no smell of sulfur dioxide (SO2). The sulfite chemical reacts with the acid and produces SO2 - actually, sulfurous acid, when in solution. When you have excess gold, less than enough sulfite will completely react with the gold and drop it and there will be no free SO2 and, therefore, no smell. When the gold is out, you will have free SO2 and a strong smell. I know I haven't explained this very well.

*Warning:* Do not stick your nose directly over the container to smell any chemical. Always keep your nose to the side and use your hand to slowly wave a little of the fumes to your nose. It's called "wafting". In the case of SO2, it doesn't take much to be able to smell it. I remember once opening an unmarked gallon jug full of an innocuous looking water-clear liquid and foolishly stuck my nose over the opening to smell it. It contained ammonium hydroxide and I was literally knocked to my knees. From that point, I ALWAYS used the hand wave method.

Of course, all of these methods are subjective. When you put several of them them together, however, with a little experience they can be quite reliable. I would suggest observing these phenomena and then proving them with stannous chloride tests.

Most reactions have changes that can be detected with the senses. Observation is very important in this business. Keeping notes is excellent.

The stannous chloride papers might be a very good idea. Let them air dry - no heat. Like you said, preservation might be a problem. Keep them in a dark sealed container. When they turn yellow, they are likely no good. Somewhere, I have a book that shows how to make all sorts of test papers. Here's an interesting one - pH paper from red cabbage:
http://chemistry.about.com/od/chemistryhowtoguide/ht/makephpaper.htm
http://chemistry.about.com/library/weekly/aa012803a.htm


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## eeTHr (Jul 21, 2009)

GSP;

Once again I haven't done this enough times to notice any cause-effect relationship with the smell when using SMB.

One thing that I did find out is that I am one of those people who can't smell SO2 as the rotten egg oder. To me, the SMB gives off a sickly-sweet acid smell. I also have read that it can really mess you up if you continue to breath it, even kill you if you breath enough of it. I did notice a major amount of smell when I added way too much SMB!

I'll be checking for this turning point in the precipitation process next time (whithou sniffing it directly!)

I've had a few instances of wind shift, and getting a direct waft of fumes from HCl or AR. The last time it happened I vowed to stop processing after that batch and build a fume hood before doing anything further.

I finished the fume hood, but I'm still trying to decide how to terminate the vent pipe (4 1/2' PVC). Right now it goes downward off the porch almost to the ground, and I have a plastic bucket under it. I thought it might condense and drip most of it into the bucket, but it doesn't. There is not enough power from the fan to put it into water, so I'm thinking I'll need to make a condenser system and run it through water, or something with a lot of baffles which can drip to an outlet. Or maybe a filter setup? I'm trying to figure which would be easiest.

I have litmus papers on my list for my next chemical order, but I think I'll try the cabbage juice in the mean time. That's really good to know, actually. I have a $30.00 digital pH meter, but you need to keep them in water for at least two hours before using them, and calibrate them in known solutions at least daily, so a quick check would be handy. Also somebody on this forum suggested setting out some litmus papers around your work area if you are wondering how much acid might be floating around that you're not aware of. I also got an fume filter mask, with dual cartridges, at Lowe's the other day! It says it's good for HCl, but doesn't mention nitric or chlorine, but it's a step in the right direction. I'll see how it goes, and if anyone has any recommendations. Fumes are bad for you!

Thanks again for your help,

Don


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## goldsilverpro (Jul 21, 2009)

Actually, the rotten egg smell is hydrogen sulfide, H2S. The SO2 smells a bit different. Sometimes, too much of many types of chemical fumes will deaden the senses and you don't know exactly what you are smelling. All you know is, it's painful enough to make you want to get the hell out of there.

If you get more than a little SO2 it your system, you'll also taste it for an hour, or so, no mater how much you rinse your mouth out. Nasty taste.

When I was in the Air Force, I taught a 40 hour course, once a month, on chemical, biological, and nuclear warfare to 30 or 40 bomb shelter managers, border patrol guys, etc. - even a General, or two. In the tech school I attended in Denver, to learn how to do this, they had "sniff kits", which was a set of about 20 big corked test tubes. Each contained about 10 ml, or so, of a different "war gas" - choking, blister, tear, etc. We removed the corks and waved a little of the fumes to our noses. The object was to be able to recognize the different gases in the field. One contained a cyanide compound and gave off the bitter almond smell and taste. I'm sure that all these were well diluted down. At the time, there was much experimentation in using LSD, somehow, as a psychoactive war agent. Unfortunately, it was not included in the "sniff kit."


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## qst42know (Jul 21, 2009)

This is clipped from the JT Baker MSDS on Nitric acid. Cartridge type respirators don't cut it.

"Personal Respirators (NIOSH Approved):
If the exposure limit is exceeded, wear a supplied air, full-facepiece respirator, airlined hood, or full-facepiece
self-contained breathing apparatus. Nitric acid is an oxidizer and should not come in contact with cartridges and
canisters that contain oxidizable materials, such as activated charcoal. Canister-type respirators using sorbents
are ineffective."

http://www.seas.upenn.edu/~nanofab/chemicals/MSDS_Acid_NITRIC.pdf


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## eeTHr (Jul 21, 2009)

q42k;

Thanks for the link.

Well now, that's just dandy. I wonder how many people here are using supplied-air resperators with nitric and AR?

Don


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## Harold_V (Jul 22, 2009)

eeTHr said:


> q42k;
> 
> Thanks for the link.
> 
> ...


Think fume hood.

Harold


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## eeTHr (Jul 22, 2009)

Thanks, Harold!


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## goldencad (Mar 27, 2010)

Hello, I need a little help,

I have stannous chloride powder i purchased a while ago. What is the best way to mix it to have a good testing liquid.


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## jimdoc (Mar 27, 2010)

http://goldrefiningforum.com/phpBB3/viewtopic.php?f=48&t=2082&hilit=stannous+chloride


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## goldencad (Mar 27, 2010)

Jim doc, thanks for the link that is exactly what i needed!!!

Carl


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## Palladium (Mar 28, 2010)

Funny what you can find with that little box in the top right hand corner.


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## pricebreaker36 (Aug 14, 2011)

H!I''m new to gold refining and to this gold forum and i just purchased a pound of gold filled of watch cases and i tried to melt down the half pound of iy into small pieces and soaked it into sulfuric acid (battery fluid acid )and sodium nitrate,and after one day of soaking it,the watch cases dissolves but it turns into like black mud and black sand,i did not see the gold at the bottom.can anyone tells me what was wrong,and can anyone help me please?
1)what can i do next?
2)how can i get the gold from it?
3)where can i buy a cheap nitric acid?


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## jimdoc (Aug 14, 2011)

pricebreaker36 said:


> HI!!!I'M NEW TO GOLD REFINING AND I JUST PURCHASED A POUND OF GOLD FILLED WATCH CASE AND I TRIED TO MELT DOWN THE HALF OF THE WATCH CASES INTO SMALL PIECES AND SOAKED IT TO SULFURIC ACID(BATTERY FLUID ACID ) AND SODIUM NITRATE,AND AFTER ONE DAY OF SOAKING IT,THE CASES DISSOLVES BUT IT TURNS INTO LIKE A BLACK MUD AND BLACK SAND ,I DID NOT SEE THE GOLD AT THE BOTTOM,CAN ANYONE HELP ME WITH THIS PLEASE?
> 1) WHAT WILL I DO NEXT?
> 2) HOW CAN I GET THE GOLD FROM THE DISSOLVED WATCH CASES?
> 3) WHERE CAN I BUY A CHEAP NITRIC ACID?




I think if you go back and edit your post to lose the ALL CAPS you may get some answers.
The answers are here to be found if you do some reading and use the search box.

Jim


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## Harold_V (Aug 14, 2011)

pricebreaker36 said:


> HI!!!I'M NEW TO GOLD REFINING AND I JUST PURCHASED A POUND OF GOLD FILLED WATCH CASE AND I TRIED TO MELT DOWN THE HALF OF THE WATCH CASES INTO SMALL PIECES AND SOAKED IT TO SULFURIC ACID(BATTERY FLUID ACID ) AND SODIUM NITRATE,AND AFTER ONE DAY OF SOAKING IT,THE CASES DISSOLVES BUT IT TURNS INTO LIKE A BLACK MUD AND BLACK SAND ,I DID NOT SEE THE GOLD AT THE BOTTOM,CAN ANYONE HELP ME WITH THIS PLEASE?
> 1) WHAT WILL I DO NEXT?
> 2) HOW CAN I GET THE GOLD FROM THE DISSOLVED WATCH CASES?
> 3) WHERE CAN I BUY A CHEAP NITRIC ACID?


It is in your best interest to edit your post, using both upper and lower case characters. It is considered shouting to post with upper case only, and is not received well. You will be chiefly ignored if you don't. 

Harold


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## pricebreaker36 (Aug 14, 2011)

]


I think if you go back and edit your post to lose the ALL CAPS you may get some answers.
The answers are here to be found if you do some reading and use the search box.

Jim[/quote]
sorry about that,thanks


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## pricebreaker36 (Aug 14, 2011)

Harold_V said:


> pricebreaker36 said:
> 
> 
> > HI!!!I'M NEW TO GOLD REFINING]
> ...


thanks harold


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## jimdoc (Aug 14, 2011)

pricebreaker36 said:


> 1)what can i do next?
> 2)how can i get the gold from it?
> 3)where can i buy a cheap nitric acid?



Next you should study the forum for a bit, and download a copy of Hoke's book.
Your gold won't go anywhere unless you trash it, just put it in a safe place.
There is plenty of info on processing gold filled on the forum.
Gold doesn't always look like gold so don't discard any powders because they don't look like gold.
Do you have stannous chloride to test for gold in solution? If not getting it is a priority.
Cheap nitric? Good luck. Basically shipping charges put it out of the cheap category, so if you can find a local source to avoid the hazmat shipping you should cut the cost down greatly.

Thanks for fixing the all caps. And don't forget about safety, your health is more important than gold.

Jim


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## pricebreaker36 (Aug 14, 2011)

thanks for quick response,right now i don't have stannous chloride.


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## jimdoc (Aug 14, 2011)

pricebreaker36 said:


> thanks for quick response,right now i don't have stannous chloride.



Then how are you going to tell if you have gold in your solution?

Jim


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## pricebreaker36 (Aug 14, 2011)

i just bought stannous chloride from ebay and i'm just waiting for it to arrive.again thanks


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## doctor (May 27, 2012)

Is there a seller of small quantities of SNCl2, for testing solutions for PM? In the US, or does anyone have any for sale?
Let me know.
Thanks
Gerry
[email protected]


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## Geo (May 27, 2012)

stannous chloride does not ship well as the shelf life is limited. the popular formula to make it your self is to use 95% tin/ 5% antimony non acid core solder dissolved in hcl (muriatic acid). cut a couple of inches of solder off the roll and fashion it to fit in a small glass container that has a top. either roll it into a ball or cut into pieces and place in the container and add 20-30 ml's hcl and let all that will dissolve go into solution.after all the reaction has stopped, you can cap it tightly.WARNING : do not cap until all the bubbles have stopped. you can filter or just use it out of the container being sure not to suck up any solids from the bottom.


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## lazersteve (Jun 2, 2012)

I sell pure tin powder on my webstore (link below) . You can make your own fresh stannous chloride using it and a little muriatic acid available from any hardware store.

Solder works but you end up with antimony in the bottom of your test solution. This does not occur with the tin powder. Another advantage of the tin powder is that it dissolves rapidly.

Once you receive/make your stannous chloride be sure to test it to make sure it is working. Make up a standard gold solution by dissolving a small foil of gold in a little HCl-Cl as seen in my videos.

Steve


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## ikielee (Aug 5, 2012)

Hello all
I am new to this and am starting to see some results thanks to the help of this site and hokes book.
one thing that baffles me is that when i am sure i have completely dropped out all i can i still test positive for something, and 
i am stuck keeping that solution , afraid to throw away any thing of value. I am working mostly with gold filled scrap
i have gotten pretty good at gauging the amount of gold to expect and in most cases am withing 1 gram either way. I use sodium metabisulfite
to drop the gold and the above stannous chloride to test.
in the scrap i am handeling i cannot see there being any platinum or paladium but i get a brown test at the end.(very brown) when left to sit it precipitates as a black powder and when more stannous is added it globs up floats to the top and begins to dissolve to brown again.
what is this. I admit i use more smb than i probably should to drop the gold. would this give the brown test results.
I also have added more smb to the solution and have dropped a very very small amout of gold but mostly when melted the metal i get from the second drop resembles silver (or lead , or murcury) as when i disslove it in AR it forms a white covering. still these metals dont give a positive test in stannous do they.
and even though i am adding what should amount to too much smb the solution still will give a brown test.
I have litterally gallons of this excess solution i am afraid to dispose of do to these test.
any help would be appreciated and i would like to thank all on this site for the help i have allready recieved.
ike


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## butcher (Aug 5, 2012)

Keep reading in Hoke's book she addresses your question in several manners, like keeping a healthy stock pot, cementing useing metals like copper, and testing for metals in solution (also those which can fool you into thinking you have something of value like iron).

Are you sure the brown reaction is not a false positive reaction caused from the use of too much SMB?


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## ikielee (Aug 5, 2012)

i was thinking it was the SMB , so i set up a test 
and it didnt show the brown.
also i negleted to mention that i am disolving all base metals with nitric (home made)
and disolving the gold in hydrochloric acid and clorox bleach. so as i said i made some of this and mixed in the SMB 
again no brown , however i didnt disolve any thing in it either.
the items i am working with have iron, i am sure but i cant see the amount i am testing at getting by the nitric treatment.
the fact of the matter is 
i got my gold i was expecting 
i need to just consider the rest for what i am sure it is
trash
thanks for the eye opener
ike


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## Palladium (Aug 5, 2012)

All you have to do is put a piece of copper in it for a couple of days. It's their are any precious metals they will attach to it and fall off. That's how you get that last bit out. That's your fail safe when you aren't sure.


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## CampB (Feb 21, 2013)

Back on Nov 28th 2012 I contacted a good member of this forum and asked about getting a positive read from a 30%/70% Nitric bath of PM's. Since then I've learned more about my getting a positive Stannous read for Au from my 30%/70% Nitric bath after parting beads with Ag, Au, and Pd in them. As a result I now have more questions. What we have concluded is that the Au is still attached to my Pd on a molecule state and that's why it shows purple in Nitric. 

My question is what's the best way to separate Au and Pd from each other. I've read to keep re-refining with AR and that's what I'm working on but that's a long process. What does Pd like more than Au? What can I give it on a molecular level that will make it drop Au and run to _____? Has someone done it before? Is there a formula or procedure you have seen to do this? 

Keep in mind I'm working with a complex ore and I'm testing anything and everything to find how to break this bond.

Any suggestions or help would be appreciated.

Thank you, 
CampB
Dan


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## solar_plasma (Mar 9, 2013)

Can SnCl2 be used for quantitative analysis in a spectrometer by comparing with known concentrations, given that there is only one kind of the metal ions, that give a positive result? I have a cheap one at school that only works with 3 defined wavelength (green, red, blue) of light showing the measured results on a pc.


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## amosfella (Mar 25, 2013)

I have a solution that I'm playing with as a test on black sands from a platinum placer mine. I'm trying to figure out what I have in the solution before I get an assay done. I put a small handful of the sands into a bucket that I had a fire going in while I was trimming dead branches off the trees. There was a fair amount of yellow smoke coming out of the bucket for a bit, and I kept the fire going till long after the yellow smoke stopped. Then I had the joy of panning the sand back out of the ash (elm wood leaves a lot of ash). After that I put a few pinches of the fine sand into a small bowl and put some hydrochloric on it. It did have some brown in it, but not much the next day, so I added a small amount of nitric to it and heated it for about 5 min. Then I let the solution sit for a day. I came back to an almost burnt orange color of solution. It has silvery metalic looking fines on the bottom of the glass that I couldn't dissolve with AR.
I mixed up some stannous chloride, and I poured a few drops of the burnt orange solution into a very small glass bowl. Then I added stannous, and the solution turned bright canary yellow, and then went clear a few seconds later. When I went back after leaving it for about an hour, the solution was brown...
Now, I'm trying to figure out what I have.
The solder I used was 97% tin/3% copper. Any ideas what I have there??



lazersteve said:


> Don,
> 
> I use this formula for making stannous and I always have the same results no matter what the source of the scrap is:
> 
> ...


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## jonn (Jul 23, 2013)

CampB, you stated your AU is attached to PD and shows purple in Nitric. I wonder? When AG in Nitric is exposed to light it turns purple. You add HCL to drop your AG and then filter out your silver chloride that forms. Test your solution after your silver is out of the mix. If for some reason you suspect there to be gold , do a small test tube sample first this way and see your results. Otherwise you may be chasing AU that is not there. Let us know what it results, Jonn.


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## Sunspot (Sep 1, 2013)

Hey guys, new to all of this but I am reading a great deal. I have a quick question about stannous chloride.

I understand this method is about making it from hydrochloric acid and tin. I actually have a container of stannous chloride, how would I use this to create a solution to test gold? Can I just mix it with water? I mean when you mix HCL and the tin you get a chloride salt and water right? So I imagine it's the same thing. 

My only other question is how many grams of stannous chloride to how many ml of water. I did do a google search but couldn't quite find an answer.


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## FrugalRefiner (Sep 1, 2013)

C. M. Hoke covers that in her book. There is a digital copy you can read on screen here: _Refining Precious Metal Wastes_. If you prefer a printed copy, you'll find a link to a printer friendly version in my signature line below.

Dave


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## Sunspot (Sep 1, 2013)

I did scan through the book before posting this but all I found was a discussion of adding hydrochloric to tin, I guess I must have missed it, I'll have a better look thanks


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## FrugalRefiner (Sep 1, 2013)

Chapter IX. 

Don't just scan the book. Read it. Then read it again.

Dave


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## Sunspot (Sep 1, 2013)

FrugalRefiner said:


> Chapter IX.
> 
> Don't just scan the book. Read it. Then read it again.
> 
> Dave



You're right. I'm going to spend the next week going over it. In fact I'm going to print it because I deal with things better in printed form. Thanks for your input, but despite my A level chemistry knowledge I have no doubt I'll be asking a few questions. 

I'm happy to say I have the method for ceramic chips in place and now I understand the AP method for removing fingers from memory. I'm leaving the palladium from monolithic stuff and the flat pack stuff until I understand the processes. 

Even though I have chemistry to a level I understand there are several processes which are quite involved, and for safety reasons I need to be careful. 

I'm building a fume hood and scrubber, along with a secondary carbon scrubber. I'm starting with the simple stuff, fingers and ceramic chips. After that I'll need a lot more research.


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## Sunspot (Sep 1, 2013)

Frugal refiner.

Thank you for your printer friendly version of Hoke. I've downloaded it and now throwing it at my inkjet


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## FrugalRefiner (Sep 1, 2013)

You're very welcome. 

As you study her book, remember it was written over 70 years ago. I'm reviewing it again, specifically looking for differences between what she teaches and procedures which are considered to be better or safer with our current knowledge. We've previously cautioned that one should not toss gasoline on while incinerating, taste their rinse waters, or pour untreated waste down the drain. I'll be adding more in the near future, such as not refining in the basement of your residence, and not using the word boil when your intention is to reduce the volume of a solution through evaporation. 

Dave


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## IdahoMole (Jul 22, 2016)

I made my first batch of stannous chloride per Steve's recipe. I put 2g of 95/5 tin/antimony solder, cut into small bits, into 100ml beaker and added 30ml of HCl. I did not use heat. After two hours the tin was dissolved so I decanted the solution off of the antimony residue into a plastic dropper bottle and added a small bit of solder. A short time later I notice there were a lot of bubbles coming off the solder. So I think to myself, bubbles equal pressure in the bottle and that's not good, must be too much free HCl. I then poured the solution back into the beaker with 4g of additional solder. I put the beaker into a coffee pot and covered it with a glass plate and left it over night. This morning the reaction was done so I decanted back into the dropper bottle with a new bit of solder. The bubbling has stopped and everything looks fine. 
Was I correct in thinking that i should consume the free HCl before bottling to prevent pressure buildup and is my stannous still good considering I have about 5g in solution rather than the 2g called for?


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## upcyclist (Jul 22, 2016)

IdahoMole said:


> I made my first batch of stannous chloride per Steve's recipe. I put 2g of 95/5 tin/antimony solder, cut into small bits, into 100ml beaker and added 30ml of HCl. I did not use heat. After two hours the tin was dissolved so I decanted the solution off of the antimony residue into a plastic dropper bottle and added a small bit of solder. A short time later I notice there were a lot of bubbles coming off the solder. So I think to myself, bubbles equal pressure in the bottle and that's not good, must be too much free HCl. I then poured the solution back into the beaker with 4g of additional solder. I put the beaker into a coffee pot and covered it with a glass plate and left it over night. This morning the reaction was done so I decanted back into the dropper bottle with a new bit of solder. The bubbling has stopped and everything looks fine.
> Was I correct in thinking that i should consume the free HCl before bottling to prevent pressure buildup and is my stannous still good considering I have about 5g in solution rather than the 2g called for?



Your stannous chloride will last longer if you actually store it with an excess of tin in the bottle. So yes, absolutely use up the free HCl--that extra bead of tin left will tell you that you are done.

And yes, your reaction should be complete before you seal your bottle. I use the fillable dropper bottles, too--HCl will eat the black rubber on your traditional bulbed glass dropper bottle.


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## upcyclist (Jul 22, 2016)

upcyclist said:


> IdahoMole said:
> 
> 
> > This morning the reaction was done so I decanted back into the dropper bottle with a new bit of solder. The bubbling has stopped and everything looks fine.
> ...


My apologies. I was multitasking instead of reading carefully what you had written.


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## IdahoMole (Jul 22, 2016)

No need to apologize. Thank you for the reply.


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## Barren Realms 007 (Jul 22, 2016)

You will probably need to filter the solution.


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## jstreet (May 3, 2020)

Harold_V said:


> eeTHr said:
> 
> 
> > In the forum handbook it lists stannous chloride test colors which are different than Hoke states.
> ...



I'm wondering where to get tin powder and what do you use to test( the test paper)


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## FrugalRefiner (May 3, 2020)

I buy tin in the form of fishing sinkers. They are available as an alternative to lead sinkers. Since tin is more expensive than lead, larger sinkers are usually still lead, but you can find the small "split shot" types in tin. Pewter is another source. Look for pewter items meant for food contact like mugs or dishes since they usually have the highest tin content.

Dave


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## DylanDownright84 (Jun 19, 2020)

What about a silver waste solution that initially tests baron, then when a few drops of hcl is added it tests positive for Pd and Pt with stannous? Also, theres no noticeable change when dmg is added except I'll sometimes see these tiny, tiny, tiny little green specks. I've been perplexed by this odd behavior when testing my solution. The stannous was made fresh a few days ago, as was the dmg solution.


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## Lino1406 (Jun 20, 2020)

DMG works at pH = 4 for Pd, pH = 8 for Ni


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## stoneware (Aug 4, 2021)

Stannous red.


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