acid leach questions

[nate44]

I have an interesting experiment going on right now. I'm trying to learn how to test ores for their mineral content. I found a recipie for SSN (saturated salt and nitric acid). I've used this to leach the ore from two locations. I tested two samples from the first location. One is just the ore in the vein, this turned yellow quickly then turned a darker orange color as time went on. The second sample from this location was out of a pocket of pyrite. We concentrated this down to the heavyist pieces (which where also the darkest) and used just a small amount of this for the second test. This one fizzed wildly for a couple hours and made the glass warm, it also ended up the same dark color.

 

The ore from the second location was totaly different. When I added the leach to the ore it fizzed and bubbled up almost out of the jar I had it in. It kept fizzing and eventualy turned a bright yellow. But the strange thing with this is that after 3 or 4 hours, the solution solidified to a jello like substance, still the same yellow translucent color. Could this be from the salt solidifying in solution?

 

For the next step of this test I need Stannous Chloride. But, I don't know where to get it. I've seen that you can make it with Tin disolved in HCL, but you have to heat the Hydrochloric acid to disolve the Tin. Does anyone know more specific information about the proccess? Like what ratio of Tin to HCL, or what temprature the HCL needs to be? Do I need to Boil it or just warm it? Also how would I make it into Stannous Chloride Dyhydrate Crystals? I understand that Stannous Chloride doesn't have a long shelf life, and I only need a couple drops for a color test.

[UC]

Tin will react with HCl without heating, but the reaction is slower. If you use concentrated HCl, it will go faster no matter what temprature. Moderate warming should help it along nicely without sending acid spatter and fumes everywhere. I'd use excess tin (so lots, and when it stops bubbling, just use the liquid as is). If you store it in an airtight container with a little extra HCl added, it should last a very long time. Making crystals is tricky and not worth the effort if you just need a solution to test with. If I needed crystals, I'd buy them to save myself the trouble.

[nate44]

Right on, thank you. I realy didn't want to boil the HCL, I don't have any of the right equipment for that. I have no problem giving it extra time to work.

[nate44]

Ok, I tried to make the Stannous Chloride, but I couldn't find a source for tin localy. So, I decided to try using a 95/5 Tin/Antimony Solder. Unfortunately, I grabbed one with Acid Core Flux. I reaserched the flux and I believe it is Zinc Chloride. Not good, since zinc is much more reactive than tin. After disolving the solder, I was left with a dark residue on the bottom. I thought that might be the tin displaced by the zinc, but when I pored off the solution and put fresh HCL onto the residue, it didn't react at all. What could this residue be?