# Stannous Chloride



## goldenye

what is the ratio for making aqueous stannous chloride?
i have stannous salts and i would like to test my ar sollution for gold.
the solution contains nitric acid, muriatic, urea, smb,h2o, maybe compounds of gold silver copper zink tin and lead.
its a mix of various ar test batches. some had high karat gold, some only had plated and filled gold jewelery.
i got this b4 reading hoke

my first batch of test solution has 3.5 grams of stanous salt, 7 ml of hcl (34%) and 15 ml of tap water but it showed no color change on my ar solution.
help?
i need the foumula and/or mixing ratios for preparing stannous chloride testing solution from salt.

HOKE SAYS"Take about a pennyweight of thestannous chloride crystals (also called tin salts) in the droppingbottle, add a pennyweight or less of tin metal, and fill the bottlethree-fourths full of water. Ordinary tap water will do. Now adda little hydrochloric acid, about 25 or 30 drops to a 30 cc. bottle."

i dont know what a pennyweight is exactly. id estimate 1-10 grams but its not clear nor safe when you are forced to guess at mixtures.also i dont have a dropper to count 25 drops and i dont know how many mL is in a 30cc bottle. i need to know exact measurements and or ratios to make stannous chloride aqueous solution to test gold.
the formula i tried making from hokes explanation is not working. i touch a q-tip to my yellow ar solution the qtip turns yellow. than i put a drop of the stannous chloride solution solution made based off of hokes suggestions. and it turned the q tip back to white...

what does it mean?
i need to know the actual working ratios and method to make a working test solution to test for gold and other precious metals
how do i make stanous chloride (aq) correctly?


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## jeneje

Look under the board index under data the first post by lazersteve, under reaction list i believe.
Ken


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## cnbarr

There is no need to double post, patience is virtue. But to answer your question stannous chloride test solution can be made a few different ways. With the stannous crystals I always nix 3-4 grams with 30-40ml of Hcl and it works great for me.
hope that helps,
Chris


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## goldenye

ok i know what a pennyweight is now 1.55grams but i still dont know whats wrong with it

i have a solution of AquaRega with 14k gold dissolved in it ( and a little remaining in the bottom of the yellow solution.) i touch a clean dry qtip to it and it turns yellow. than i add a drop of my testing solution and the qtip returns to white. my testing solution is off i think. i remade my testing solution by boiling a gram of stannous chloride in 20 ml of (34%)hcl until the stannous salts all dissolved. i repeated my test and the solution still returns the q-tip head to white from the yellow color it got from the gold ar solution.... what does it mean if it turns white? and what am i doing wrong that preventing it from turning purple?


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## cnbarr

Do you have a standard known gold bearing solution to cross check your stannous to ensure it is working?

How much 14k gold did you start with? And did you inquart first then remove base meatals and silver with dilute nitric?

A few more details about your process would certainly help.

Edit : I fear the issue may not be your stannous but possibly your process, but hopefully I'm wrong.


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## Harold_V

goldenye said:


> i dont know what a pennyweight is exactly. id estimate 1-10 grams but its not clear nor safe when you are forced to guess at mixtures.


The precious metals industry has used the Troy system for a long time. Every reader should become familiar with its use. Here's a few things that will help you better understand.

A troy ounce contains 480 grains. 
A penny weight (dwt) contains 24 grains
a troy ounce contains 20 dwt. 
A gram contains 15.432 grains

I DO NOT promote the use of grams for working with gold. Never did, and never will. 



> also i dont have a dropper to count 25 drops


Chemical supply houses sell "dropping bottles". How anyone who refines can get along without them is a mystery to me. They are not cheap, but you buy them but once, and they'll last a lifetime unless you break them. I recommend them highly. I used two sizes, 2 ounce and 4 ounce. 




> i touch a q-tip to my yellow ar solution the qtip turns yellow. than i put a drop of the stannous chloride solution solution made based off of hokes suggestions. and it turned the q tip back to white...
> 
> what does it mean?


That would indicate the lack of gold in solution. 

I'm very outspoken about the methods I endorse, and Q tips aren't included. 

Reason? 

Because anything used for testing has potential value. It's much easier to rinse a spot plate to one's stock pot than it is to incinerate Q tips, especially if they're made of plastic. Do consider the use of a spot plate instead. It's far more flexible, in particular if you're doing multiple testing on a solution that contains mixed values. In all my years of refining, I NEVER used a Q tip. Couldn't see a good reason to do so. 



> i need to know the actual working ratios and method to make a working test solution to test for gold and other precious metals
> how do i make stanous chloride (aq) correctly?


Read Hoke. Read it again. Read it until these questions are answered. It's all in there. 

Harold


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## goldsilverpro

Different eye droppers will dispense different sized drops. Most of the straight glass ones from a pharmacy have a fairly small hole and dispense about 23-25 drops per ml. If they are made of plastic, the number will probably be higher, depending on the hole size. To determine the number of drops per ml from any eyedropper:

If you have a scale that will weigh to 2 decimal places, tare a small dry beaker and count how many drops of distilled water it takes to weigh as close as possible to 1.00 grams.

If the scale only reads to 1 decimal place, I would probably count the drops until I had 5.0 or 10.0 grams and then divide the total number of drops by 5 or 10.

In earlier years, I used many of those glass lab dropper bottles that you can adjust by slightly turning the ground glass stopper. However, I greatly prefer the straight glass eyedroppers that are cheap, readily available from a pharmacy, never leak, and are very easy to clean. I usually keep about 6 of them on hand.


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## Geo

i also use the glass droppers. the only setback is the container and the dropper is separate. for weaker solutions, i use recycled plastic eye drop bottles (like visine) that have been washed.for concentrated solutions of sulfuric, nitric and hcl, i use glass bottles with screw on lids and a glass dropper.


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## lazersteve

Harold,

Not to diminish your stance on using a spot plate as I have used them myself for several years, but here is what I have noticed when working with swabs verses my use of a multiple cavity spot plate.:

1). Swabs are easier to quickly obtain for the hobby refiners. You can buy paper sticked swabs at any grocery or drug store.
2). I can dip a swab into the solution to be tested and don't need a separate clean dropper to get my test sample out of the pregnant solution. 
3). You always have to throughly water rinse the sample dropper used to extract the test sample after every test to avoid cross contamination. 
4). When the spot plate cavities are all filled, you have to rinse all that tin solution into your stock pot. With swabs you simply toss them in the burn pile and incinerate them with your filters. I have several burn piles: One for Au, one for Ag, and one for PGMs.
5). The spot plate is delicate (I've broken two  ) and requires storage when you are done using it for it's own protection. 
6). I have had false positves from the adjacent cavities bleeding into each other.
7). Swabs are* not good *at testing multiple precious metals in solution. This is where I prefer a test tube. For example when Pd is suspected by the intial swab test I draw a sample into a test tube and add DMG. Once the solids settle, I then dip a swab in the test tube and check for other precious metals.

I feel it's all a matter of personal preferences and I completely respect your preferring a spot plate as they do provide a good color contrast when testing.

Steve


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## goldenye

q tips r cheaper and disposable and i doubt it would absorb enough gold to be worth saving.



goldsilverpro said:


> Different eye droppers will dispense different sized drops. Most of the straight glass ones from a pharmacy have a fairly small hole and dispense about 23-25 drops per ml. If they are made of plastic, the number will probably be higher, depending on the hole size. To determine the number of drops per ml from any eyedropper:
> 
> If you have a scale that will weigh to 2 decimal places, tare a small dry beaker and count how many drops of distilled water it takes to weigh as close as possible to 1.00 grams.
> 
> If the scale only reads to 1 decimal place, I would probably count the drops until I had 5.0 or 10.0 grams and then divide the total number of drops by 5 or 10.
> 
> In earlier years, I used many of those glass lab dropper bottles that you can adjust by slightly turning the ground glass stopper. However, I greatly prefer the straight glass eyedroppers that are cheap, readily available from a pharmacy, never leak, and are very easy to clean. I usually keep about 6 of them on hand.



you said 25 droms are in 1 mL. so does that meal hoke is saying to use 1 mL of Hcl per pennyweight of stanous salt?

i was more interested in how many mL is in 25 drops, not the number of drops in a mL but thanks anyway i will still try and see if that works

i will try to see if that is correct by using 1 mL of HCl and 1.55 gram of the salt


cnbarr said:


> There is no need to double post, patience is virtue. But to answer your question stannous chloride test solution can be made a few different ways. With the stannous crystals I always nix 3-4 grams with 30-40ml of Hcl and it works great for me.
> hope that helps,
> Chris



or should i mix 10 mL of HCl with a gram of stannous salt crystals?


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## cnbarr

Hey goldeneye,
I mix 3g stannous crystals with 30-40ml of Hcl, I believe Steve mixes his with 2g pure tin powder and 30ml of Hcl,until all has dissolved, either way it works out to be 1g of tin or stannous crystals to 10-15ml of Hcl. And both ways are equally acceptable.


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## goldenye

cnbarr said:


> Hey goldeneye,
> I mix 3g stannous crystals with 30-40ml of Hcl, I believe Steve mixes his with 2g pure tin powder and 30ml of Hcl,until all has dissolved, either way it works out to be 1g of tin or stannous crystals to 10-15ml of Hcl. And both ways are equally acceptable.



what strength of Hcl do you use? 

1 gram salt/ 10 mL Hcl at 34% is the same as 1 gram salt/ 5 mL at 68% Hcl


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## Geo

goldenye said:


> cnbarr said:
> 
> 
> 
> Hey goldeneye,
> I mix 3g stannous crystals with 30-40ml of Hcl, I believe Steve mixes his with 2g pure tin powder and 30ml of Hcl,until all has dissolved, either way it works out to be 1g of tin or stannous crystals to 10-15ml of Hcl. And both ways are equally acceptable.
> 
> 
> 
> 
> what strength of Hcl do you use?
> 
> 1 gram salt/ 10 mL Hcl at 34% is the same as 1 gram salt/ 5 mL at 68% Hcl
Click to expand...


unless its under pressure, 32% is the highest concentration of hcl you can get. it can be higher, but it will not stay that way under normal atmospheric pressure.speaking from experience, for most applications of hcl i can think of, dilute hcl will work just fine (even 15% should be suitable).


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## lazersteve

Geo,

If memory serves me correctly I believe the maximum concentration of HCl is 38% at STP (standard temperature pressure).

Steve


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## Harold_V

goldenye said:


> q tips r cheaper and disposable and i doubt it would absorb enough gold to be worth saving.


That's not a wise thing to say. If you work with concentrated solutions, a Qtip could easily have a few dollars worth of value contained within. Tossing them makes no sense at all. 

Harold


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## Harold_V

lazersteve said:


> 1). Swabs are easier to quickly obtain for the hobby refiners. You can buy paper sticked swabs at any grocery or drug store.


That has the potential to be beneficial, but if they are wooden or plastic, they are best avoided. 


> 2). I can dip a swab into the solution to be tested and don't need a separate clean dropper to get my test sample out of the pregnant solution.


I don't recall EVER having to use a dropper. Ever. I routinely had a glass rod in my vessels, which was used to extract a trace of solution for testing. Rarely did I even require a drop---just a trace--a small fraction of the solution absorbed by a Qtip---and with concentrated solutions, that can be considerable in value. 


> 3). You always have to throughly water rinse the sample dropper used to extract the test sample after every test to avoid cross contamination.


Non issue. They weren't used, as they weren't required.


> 4). When the spot plate cavities are all filled, you have to rinse all that tin solution into your stock pot. With swabs you simply toss them in the burn pile and incinerate them with your filters. I have several burn piles: One for Au, one for Ag, and one for PGMs.


No real difference, as in both cases, a wise person incinerates prior to processing. In my case, where I did all my recovery by furnace, tin didn't report in the final product, so it wasn't an issue. Solids from the stock pot were filtered only after the bulk of the solution was siphoned, so filtration wasn't an issue. I had no problems with residual tin, thanks to my procedures. They worked admirably for years. 


> 5). The spot plate is delicate (I've broken two  ) and requires storage when you are done using it for it's own protection.


While it's true that they can be broken, I used the same one for more than 20 years. I never broke one, although I had a spare. Both went with the business when it was sold. 

I can see that one could lose a spot plate, just as one could lose a beaker or flask. Care in handling is a requirement, but that should be a top priority at the outset, as a liter of gold chloride can be broken, too, with a much greater value. One learns to work carefully. 


> 6). I have had false positves from the adjacent cavities bleeding into each other.


I must confess, I don't recall EVER having issues with false positives----and if the spot plate is kept clean and dry, there is no bleeding. 


> 7). Swabs are* not good *at testing multiple precious metals in solution. This is where I prefer a test tube. For example when Pd is suspected by the intial swab test I draw a sample into a test tube and add DMG. Once the solids settle, I then dip a swab in the test tube and check for other precious metals.


In such a case, I preferred to work with much smaller samples. I used a spot plate much as you do a test tube, just most likely with less fluid per test. That may or may not be, however, as I am not in your lab to see how you test. I preferred, by far, the white background of the spot plate for making determinations of color, however. 

All in all, I am of the opinion that how one builds habits is what will dictate what is most comfortable. As I had no clue, I followed Hoke's teachings and was well satisfied with the results. As in many instances, there most likely is not a right and wrong with these procedures, just different ways of achieving the same end result. I was (and am) a creature of habit. I do not welcome change easily, therefore I promote that which I learned and used with success, which appears to be what you do. 

It's all good! 

Harold


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## goldenye

Harold_V said:


> goldenye said:
> 
> 
> 
> q tips r cheaper and disposable and i doubt it would absorb enough gold to be worth saving.
> 
> 
> 
> That's not a wise thing to say. If you work with concentrated solutions, a Qtip could easily have a few dollars worth of value contained within. Tossing them makes no sense at all.
> 
> Harold
Click to expand...


thats good to know. i didn't realise i could be wasting so much, with such a small quantity. especially when the q-tips add up.
a few dolars here a few there soon its a chunk of change that could have been used for more supplies


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## Harold_V

goldenye said:


> Harold_V said:
> 
> 
> 
> 
> 
> goldenye said:
> 
> 
> 
> q tips r cheaper and disposable and i doubt it would absorb enough gold to be worth saving.
> 
> 
> 
> That's not a wise thing to say. If you work with concentrated solutions, a Qtip could easily have a few dollars worth of value contained within. Tossing them makes no sense at all.
> 
> Harold
> 
> Click to expand...
> 
> 
> thats good to know. i didn't realise i could be wasting so much, with such a small quantity. especially when the q-tips add up.
> a few dolars here a few there soon its a chunk of change that could have been used for more supplies
Click to expand...

My attitude towards refining dictated that anything that touched the process had some value, thus it was never discarded. As a result, I incinerated and stored all of my waste materials. 
If you work with just a few grams of gold in a large volume of solution, sure, your Q tips may not be worth much, but why toss them? Better yet, if you'd use a spot plate, recovery is painless. Rinse the spot to your stock pot and move on. Nothing to bother with, and no loss. I even wiped the stain from mine, as it, too, represented value. A small piece of paper towel works perfectly well. 

At the risk of repeating some boring data, when I processed my waste materials, I recovered right at 200 troy ounces of gold, along with a substantial amount of platinum and palladium. 
One Q tip makes little difference, but when you look at the big picture, you may be tossing a considerable amount of value. My comments about my waste material should encourage you to take a different approach, but do keep in mind, I refined commercially, albeit on a small scale. You might not recover the same volume of material, but it's a real pleasant surprise to recover values that would have otherwise been discarded. It's also one hell of a savings plan, in particular if you don't convert the incinerated material to accessible values. Makes it hard to spend what you don't have in your hands. 

By now you likely realize that I am not keen on the use of Q tips. For me, they make no sense. However, the one place they shine is if you hope to keep a sample of a test. I don't recall needing to do that, but it sure makes it easy if you do so routinely. I still maintain that a spot plate is the best possible world when it comes to testing these solutions. If it wasn't, I suspect there'd be something offered in their place. I'm not aware that there is, at least from chemical supply houses. 

Harold


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## goldpete

i have a similar problem , i bought stannous chloride from my chemical supplier and it came in crystal form , how do i make it into asolution to test for the presence of gold in my AR


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## Harold_V

goldpete said:


> i have a similar problem , i bought stannous chloride from my chemical supplier and it came in crystal form , how do i make it into asolution to test for the presence of gold in my AR


Hoke covers that extensively in her book. 

Harold


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## jimdoc

goldpete said:


> i have a similar problem , i bought stannous chloride from my chemical supplier and it came in crystal form , how do i make it into asolution to test for the presence of gold in my AR



http://goldrefiningforum.com/phpBB3/viewtopic.php?f=48&t=2082&p=17541&hilit=stannous#p17541


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## marlyn

Would it work, if I use stannous chloride and muriatic acid only (without metalic tin) ? :shock:


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## FrugalRefiner

marlyn, I answered you in your other post. Please don't double post.

Dave


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## marlyn

FrugalRefiner said:


> marlyn, I answered you in your other post. Please don't double post.
> 
> Dave



Sorry for that Dave, 
I found other post more appropriate, therefore I wrote it again there. I did not find the way how to delete my post from this thread after... :|


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## salman1122

hello guys. 
i have stannous chloride (SnCl2 ) in crystal form . i wanna prepare stannous chloride solution for gold testing . can you tell me how to prepare solution? thanks.


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## jimdoc

salman1122 said:


> hello guys.
> i have stannous chloride (SnCl2 ) in crystal form . i wanna prepare stannous chloride solution for gold testing . can you tell me how to prepare solution? thanks.




http://goldrefiningforum.com/phpBB3/viewtopic.php?f=48&t=2082&p=17541&hilit=stannous#p17541


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## salman1122

thanks bro. it helped . it says you have to put some solid tin the solution to keep it fresh and in dynamic equilibrium . i dont have tin metal . i put 1g of sncl4 in 13ml of hcl and i became milky . after heating solution become clear then i stored it. would it work without tin?


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## FrugalRefiner

salman1122 said:


> would it work without tin?


Yes, it will work without the tin, but it won't last as long. The stannous chloride eventually oxidizes to stannic chloride. When it stops giving a positive reaction, make a new batch.

Dave


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## g_axelsson

salman1122 said:


> thanks bro. it helped . it says you have to put some solid tin the solution to keep it fresh and in dynamic equilibrium . i dont have tin metal . i put 1g of sncl4 in 13ml of hcl and i became milky . after heating solution become clear then i stored it. would it work without tin?


SnCl4 is stannic chloride
SnCl2 is stannous chloride, this is what is used for detecting gold in solution.
https://en.wikipedia.org/wiki/Tin_chloride

I don't know if mixing SnCl4 with HCl is creating SnCl2 or not.

Göran


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## salman1122

sorry. i forgot the formula of stannous chloride .sncl4 in solid form is called butter of tin (yummy name  ) .by the way it worked . thank a lot guys for the help.


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## Worms4u

I am making my first batch of Stannous Chloride, and I am wondering something. Should I continue to add small portions of tin until there is no reaction left from the HCL, or is it OK if there is still some active HCL in the solution?


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## g_axelsson

Worms4u said:


> I am making my first batch of Stannous Chloride, and I am wondering something. Should I continue to add small portions of tin until there is no reaction left from the HCL, or is it OK if there is still some active HCL in the solution?


A bit of excess HCl doesn't hurt the reaction but if you have some tin left over in the bottle then the stannous holds better and doesn't go bad as fast as if you have excess HCl. So the recommendation is to add more tin until there is no reaction and not filter off the tin.

Göran


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## FrugalRefiner

Always keep some undissolved tin in your stannous. Stannous chloride (SnCl2) oxidizes to become stannic chloride (SnCl4), but stannic chloride reacts with tin to create more stannous chloride. 8) 

Dave


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