Help with Stannous Chloride

[kkmonte]

I'm trying to make stannous chloride and i'm running into some problems. First of all, I had purchased powder tin (or at least what I thought was powdered tin) from ebay via this auction:

http://www.ebay.com/itm/Tin-Metal-Powder-High-Purity-99-Fine-Mesh-1-2-LB-Net-Wt-/160891778408?ssPageName=ADME:X:RTQ:US:1123

I took 30 ML of HCL (like all the instructions I see) and I added 1 gram of of the tin powder. The first two times I did this, it was outside in my barn (probably 20 or so degrees). The powder immediately turned into a hunk of hard metal with no bubbles or anything. HCL color didn't change.

I then sent an email to the guy i bought it from asking him about it, he said it is indeed pure tin powder, and if it wasn't he would have had alot of angry customers. He said maybe it has oxidized.. He sent it to me in a double ziplock bag that I immediately put in a glass jar with a cover. I've only had it for 2-3 weeks or so.

Then last night, I was thinking that I read that some people add heat to the HCL and tin. So I added some heat to the HCL prior to adding the tin powder, got the HCL almost boiling, and then added the tin powder, and again same deal. big hardened hunk of silver stuff.

So I don't think I could be doing anything wrong here.. do you guys think the stuff I got was just not pure tin? The guy has offered me a refund.

 

[FrugalRefiner]

kkmonte,

What is the source of your HCl, and what is it's strength? Have you used it in any other recovery or refining processes yet, and if so how did it behave. My first thought would be that it might be one of the new "safer" or "green" products. These might contain buffers that could be interfering with dissolving the metal (which is what they're designed to do).

It pretty much needs to be the HCl or the tin. I looked at the seller's feedback and he does seem to have quite a few satisfied customers who have purchased the same tin powder.

If it's not the tin, it's probably the HCl,

Dave

 

[kkmonte]

Hi Dave, thanks for responding, I got the HCL at lowes, it wasn't the "safer" one they have although it is made by Kleen Strip. Here are two pics of the label. To answer your other questions, I used it in a small 1/3 lb of fingers in an AP process and it seemed to work, although I don't have anything to really compare it to, but It did dissolve the copper, the gold flakes fell off, and with some bleach dissolved the gold flakes.

Since it was my first test batch (more so of just getting the procedure down), i haven't finished drying/decanting my gold powder to check my yield. Since I processed the fingers myself, they were cut super close so i was hoping for the higher side for the yield. Assuming the 2-3 grams per lb, then i was hoping for 1 gram for the 1/3 lb of gold fingers.

Here are the pics.

 

[samuel-a]

Was the acid yellow?
Sometimes, just a small Fe contamination may interfere with Sn dissolution

 

[jmdlcar]

The Muriatic Acid I use is made by (Smart). You can buy it at Lowe's for $12.98 for 2-Gallon Muriatic Acid Item #: 51864 Model #: 2118 2X1.

 

[kkmonte]

Was the acid yellow?
Sometimes, just a small Fe contamination may interfere with Sn dissolution

A very slight hint of yellow but overall pretty clear.

 

[kkmonte]

The Muriatic Acid I use is made by (Smart). You can buy it at Lowe's for $12.98 for 2-Gallon Muriatic Acid Item #: 51864 Model #: 2118 2X1.

I just checked two local lowes, they don't carry that near me. The only two kinds they have is the kind I bought and the other "Smarter Muriatic Acid" by Kleen as well. That is only like 20% strength and I figure that has all sorts of "friendly" things in it that will interfere. I bought the "most dangerous" one I could find. =/ Home depot only has the smarter safer muriatic acid as well.

 

[jmdlcar]

The Muriatic Acid I use is made by (Smart). You can buy it at Lowe's for $12.98 for 2-Gallon Muriatic Acid Item #: 51864 Model #: 2118 2X1.

I just checked two local lowes, they don't carry that near me. The only two kinds they have is the kind I bought and the other "Smarter Muriatic Acid" by Kleen as well. That is only like 20% strength and I figure that has all sorts of "friendly" things in it that will interfere. I bought the "most dangerous" one I could find. =/ Home depot only has the smarter safer muriatic acid as well.

I would do a google search on the internet for "Smart Products Muriatic Acid" that how I found it.

 

[lazersteve]

I add my tin powder to the test tube first followed by the HCl, but I still get the 'lump' effect you mentioned. The lump does dissolve after a few hours of slow fizzing. A little stirring with a glass rod helps break up the surface tension of the fine powder and makes it fizz more intensely and dissolve faster. The stannous chloride works fine once it clears from the opacity caused by the fizzing bubbles. Once the fizzing and bubbles cease I stopper the test tube with a ground glass stopper and it functions perfectly until the test tube is emptied from repeated use.

Steve