Stannous Chloride Fail - Turns purple before use?

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Aus_Gold

New member
Joined
Feb 16, 2014
Messages
2
Hi, I'm new to refining and the forum.
I have recently tried to have a go at making some stannous chloride but am having troubles with this basic step.
I know Hoke says to use 1 oz. stannous chloride crystals and 1 oz. or less pure tin metal—mossy, granular, or foil, mixed with HCL and a little H2O, but i have read on this forum and a few other places i can make with just the HCL and tin (either 98% tin solder or tin powder). I live in rural australia so refining chemicals are hard to come by, so i thought id try the latter method.

I have tried this a few times, each time adding about 20 - 30 Mls of HCL. Then i have added solder the first time (it was 60% tin and 40% lead, not good enough i know) but it came out a bright clear purple after being on a very low heat for about 10 mins.

I then ordered an oz of 999 tin off ebay, couldnd't find tin powder.

I did exacly the same thing again, 25mls HCL and added 2 grams 999 tin (was a oz block i cut little bits off) then heated slowly. It had a milky white look for a bit, but then the same purple hue. I thought maybe i over boiled (or maybe a very small presence of gold from running a few acid peroxide mixes in the beaker previously, but unlikely) so i thoroughly washed beaker and tried same method again but with virtually no heat... Same purple...
So i did the same again (30Mls HCL to 1.5 grams of 999 tin) in a clean unused glass jar, only slightly heated till bubbles started to form a bit more rapidly and left it for a few hours. Sure enough, same purple colour. If i use it to test some AR i have diluted some scrap ceramics cpus (about 1lbs, there was a few pentium 90mhz and a pentium pro mixed in so im pretty sure there should be some gold in solution) it doesnt leave a purple stain when added to tissue paper and i don't get any reaction when adding a drop or two of AR solution (now a nice emerald green).

I cant seem to find anywhere online someone has had the same problem (turning purple before use). I need to know a consistent way to make good SNCl2 (i think thats right) so i can test my soultions to be sure of what im doing (and learning correctly), i dont have a soulution with known gold amount yet. I would be very grateful for any advice or comments you might have.
Thanks,
Steve B
 

Attachments

  • sncl2 purple.jpg
    sncl2 purple.jpg
    1.2 MB · Views: 223
I don't recall reading about anyone having the same problem. It sounds like you've already eliminated a couple of the possibilities by trying a different source of tin and a different vessel. From what you've written, the only thing I see that has been consistent in every batch has been the HCL, so that makes it suspect. If you can get some HCl from a different source, it might "clear up" the problem. HCl is often impure unless it's lab quality stuff.

Dave
 
Looks like a positive test for gold to me. Any chance your HCl or the tools used (pipette, beaker, etc.) got "contaminated" with gold? It doesn't take much to show positive for gold.
 
Just wanted to mention that, if it is the HCl that is causing the "problem", it can be marked and used for making your acid/bleach solution or your AR and then any gold that it contains will eventually be recovered.
 
Could the eco friendly version of HCL cause the purple color? I have never used it, so I am curious if that could be a possibility.
 
sharkhook said:
Could the eco friendly version of HCL cause the purple color? I have never used it, so I am curious if that could be a possibility.
Click to expand...

I think the only difference is the eco friendly HCl is 25 percent and the regular muriatic acid is 31.45 percent.

I've never tried the eco friendly stuff so this is just a guess from reading the MSDS for each one. I think either one would work for making stannous chloride. Either one would cause the purple color if they got contaminated with gold.

Here's an idea to test if it is the acid that is the problem. Put a piece of your tin (solder or whatever) in a test tube or other heatable container (not metal) and put a little vinegar in it. Heat it up until the tin bubbles and some dissolves just like with the HCl except it will take more heating. You could even try adding a small amount of hydrogen peroxide to the vinegar to help the tin to dissolve a little quicker but you will still have to heat it. Test this stannous substitute with a drop or two of known gold containing solution. If it gives a positive test, then take a drop or two of your suspected HCl and add a couple drops of the vinegar solution you made. I've been using a white, plastic spoon as a spot plate but Q-tips should work also.

This will save you from buying a new bottle of acid if that isn't the problem. HCl works better to make the stannous chloride but I have tried making it using vinegar and got it to work. The only real problem I can see with doing this is that lead will dissolve in vinegar and make it much more dangerous (water soluble if I remember right). Only make a little bit and don't use solder containing lead. A few mL should be plenty.
 
if the weather is good tomorrow, i will make a short video on how i make my stannous chloride and post it under Tutorials.
 
bmgold2 said:
Here's an idea to test if it is the acid that is the problem. Put a piece of your tin (solder or whatever) in a test tube or other heatable container (not metal) and put a little vinegar in it. Heat it up until the tin bubbles and some dissolves just like with the HCl except it will take more heating. You could even try adding a small amount of hydrogen peroxide to the vinegar to help the tin to dissolve a little quicker but you will still have to heat it. Test this stannous substitute with a drop or two of known gold containing solution. If it gives a positive test, then take a drop or two of your suspected HCl and add a couple drops of the vinegar solution you made. I've been using a white, plastic spoon as a spot plate but Q-tips should work also.

This will save you from buying a new bottle of acid if that isn't the problem. HCl works better to make the stannous chloride but I have tried making it using vinegar and got it to work. The only real problem I can see with doing this is that lead will dissolve in vinegar and make it much more dangerous (water soluble if I remember right). Only make a little bit and don't use solder containing lead. A few mL should be plenty.
Click to expand...

Thanks everyone for the help, was surprised with amount of help already! I think you guys are right on about the acid being the issue. The last batch of stannous i tried i used a clean glass and just clean (well straight from bottle anyway) hcl and tin, didn't stir or touch with anything and still the exact same purple. The brand HCL i got was "BONDALL" didn't have a % labelled, but does say it is 320G/L, which i'm guessing must equate to 32%. It is marked as use for etching concrete floors or PH adjuster for pool. I will try bmgolds vinegar method and see what happens. I'll also try a different brand HCL, is there a certain thing i should look for or this one just happens to have something they add possibly to make enviro freindly? (possibly gold hahah)
Thanks again for all your help ill post an update when i get time to try your suggestions.

-Steve B
 
Is this the one you are using :?:
http://bondall.com/misc/hydrochloric_acid.html

if so, then here is the MSDS from the bottom of the item description. It says it contains Titanium dioxide :shock:
 

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  • MSDS_Hydrochloric_Acid.pdf
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There are a few posts about
Hcl in Australia. I believe one was something about
Red color
Anyways
Niteliteone would titanium dioxide turn SnCl2 purple

About the eco stuff, never used green bottle but have used
Home depots 14% hcl in a regulae muriatic acid bottle
And there is no difference


Hope this helps steyr223 rob
 
Try heating just some acid and letting it cool just like you would, but without the tin. See what color it is.
 
Ding, ding, ding, we have a winner. Ralph, you the man. Public service notice, do not use Bondall muriatic acid to make stannous chloride.

muriatic acid.png
 
Aus_Gold said:
Hi, I'm new to refining and the forum.
I have recently tried to have a go at making some stannous chloride but am having troubles with this basic step.
I know Hoke says to use 1 oz. stannous chloride crystals and 1 oz. or less pure tin metal—mossy, granular, or foil, mixed with HCL and a little H2O, but i have read on this forum and a few other places i can make with just the HCL and tin (either 98% tin solder or tin powder). I live in rural australia so refining chemicals are hard to come by, so i thought id try the latter method.

I have tried this a few times, each time adding about 20 - 30 Mls of HCL. Then i have added solder the first time (it was 60% tin and 40% lead, not good enough i know) but it came out a bright clear purple after being on a very low heat for about 10 mins.

I then ordered an oz of 999 tin off ebay, couldnd't find tin powder.

I did exacly the same thing again, 25mls HCL and added 2 grams 999 tin (was a oz block i cut little bits off) then heated slowly. It had a milky white look for a bit, but then the same purple hue. I thought maybe i over boiled (or maybe a very small presence of gold from running a few acid peroxide mixes in the beaker previously, but unlikely) so i thoroughly washed beaker and tried same method again but with virtually no heat... Same purple...
So i did the same again (30Mls HCL to 1.5 grams of 999 tin) in a clean unused glass jar, only slightly heated till bubbles started to form a bit more rapidly and left it for a few hours. Sure enough, same purple colour. If i use it to test some AR i have diluted some scrap ceramics cpus (about 1lbs, there was a few pentium 90mhz and a pentium pro mixed in so im pretty sure there should be some gold in solution) it doesnt leave a purple stain when added to tissue paper and i don't get any reaction when adding a drop or two of AR solution (now a nice emerald green).

I cant seem to find anywhere online someone has had the same problem (turning purple before use). I need to know a consistent way to make good SNCl2 (i think thats right) so i can test my soultions to be sure of what im doing (and learning correctly), i dont have a soulution with known gold amount yet. I would be very grateful for any advice or comments you might have.
Thanks,
Steve B
Click to expand...
I have found that using Bondall HCl from Bunnings will not work well. The Bondall version will turn red when hydrogen peroxide is added. Maybe that is why your stannus solution color is not quite right. I get my HCl from a pool chemical supplier that does not used the Bondall brand.
 
I wish I read this last week…in Australia, used Bondall HCl and used lead and silver free solder (contains tin and copper, but couldn’t find what percent Cu)
My solution turned purple!
I thought it may have been the Cu as I read a small amount may dissolve in HCL
 

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