Sure simply atomize pure silver! :lol:
Urea, its use in refining
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HAuCl4
Well-known member
Next time I have a chance with this alloy and solution of nitrates, I'll try ultra fine pure silver foil in a shaker to cement Pd and Pt, before filtering and retrieving the silver.4metals said:
Why is HCl better for dropping the silver chloride, than NaCl or KCl in powder form?. One would have less liquid and much less nitric acid, that's an advantage that I can clearly see?. :?:
kuma
Well-known member
Hello all , how are tricks today?
I hope all is well!
I was looking for information on a different subject this morning , and I came across the following (link) and remembered this thread , thinking that someone was looking for silver powder.
(I also found some of the information in the Datasheets section quiet interesting) ;
http://heraeus-thickfilm.com/en/productsapplications/preciousmetalpowders/precious_metal_powders_1.aspx
http://www.natureer.com/uploadfile/201012/26/0E213240437.jpg
All the best everybody , and kind regards ,
Chris :mrgreen:
I hope all is well!
I was looking for information on a different subject this morning , and I came across the following (link) and remembered this thread , thinking that someone was looking for silver powder.
(I also found some of the information in the Datasheets section quiet interesting) ;
http://heraeus-thickfilm.com/en/productsapplications/preciousmetalpowders/precious_metal_powders_1.aspx
I did find this image of fine Ag powder ;samuel-a said:
http://www.natureer.com/uploadfile/201012/26/0E213240437.jpg
All the best everybody , and kind regards ,
Chris :mrgreen:
4metals,
I had very good success with Pt and Pd after eliminating the nitric with sulfamic. The AR contained up to 50% nitric and, therefore, it ended up with lots of sulfuric and little HCl.
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Concerning black silver powder. In general, for any metal I have seen, the smaller the particle size, the darker the powder. I think that it has to do with our sight limitations of reflections. I would experiment with different reductants at different solution strengths, reductant strengths, temperatures, etc. However, I have only seen very dark silver a few times and I can't remember the conditions. Most is medium gray or whiter.
With gold, it is different in that a range of shades - from light tan to black (to colloidal pink/purple) - are fairly common. Although dark gold powder often indicates low purity, it can also be due to particle size.
I had very good success with Pt and Pd after eliminating the nitric with sulfamic. The AR contained up to 50% nitric and, therefore, it ended up with lots of sulfuric and little HCl.
-------------------------------------
Concerning black silver powder. In general, for any metal I have seen, the smaller the particle size, the darker the powder. I think that it has to do with our sight limitations of reflections. I would experiment with different reductants at different solution strengths, reductant strengths, temperatures, etc. However, I have only seen very dark silver a few times and I can't remember the conditions. Most is medium gray or whiter.
With gold, it is different in that a range of shades - from light tan to black (to colloidal pink/purple) - are fairly common. Although dark gold powder often indicates low purity, it can also be due to particle size.
You hit the nail on the head Chris. Cruddy gold is usually very fine while really high quality gold is spongy and very light in color.
I believe this is best described with statistical mechanics (like any nucleation theory). I'd be glad to get more into it if y'all are keen on hearing my thoughts.
I will take some photographs of crappy gold and really nice gold under the electron microscope.
Really nice gold rinses well. Really crappy gold doesn't. Pore structure and relative surface area to volume ratios must be at play.
I believe this is best described with statistical mechanics (like any nucleation theory). I'd be glad to get more into it if y'all are keen on hearing my thoughts.
I will take some photographs of crappy gold and really nice gold under the electron microscope.
Really nice gold rinses well. Really crappy gold doesn't. Pore structure and relative surface area to volume ratios must be at play.
There is no need to use urea simply add hcl or salt to precipitate your silver, failing that cement it with copper.
I'm starting to think that you are dangerous. What are you doing and why are you even thinking about urea?
Topher_osAUrus
Well-known member
Use the excess to dissolve more metal...
Less wasteful, more smarter-er
Less wasteful, more smarter-er
Topher_osAUrus
Well-known member
Uh, no. I think there is a translation break down going on.
When you are dissolving your metal, the bubbles generated by that can carry off values if its too aggressive.
How can we stop that - Many ways
-add a reflux/condesor to catch it
-add a watch glass and only fill the vessel 1/3 of the way
-if using a scrubber, add an empty flask before the a-b train to catch values
-let the reaction generate its own heat at first, adding heat near the end of the reaction
Evaporating is different than boiling, while evaporation takes place during boiling, for our purposes that is not needed. Why? Because the bubbles lose values, so slow evaporation is required. Sure, it takes forever and a day to evaporate without boiling, but not if you increase the surface area of the solution being evaporated. I.E. use a shallow wide vessel on low heat -just enough to steam or make tiny tiny tiny bubbles seen on the bottom
I missed a couple points in there somewhere, but hopefully i conveyed the message well enough. Dont over think it, well, do. Do overthink it actually. Just dont focus on the small trivial matters that cost you more money in the end than what they are worth. Theres a saying for that. But i can't think of it right now.
Time for more coffee
When you are dissolving your metal, the bubbles generated by that can carry off values if its too aggressive.
How can we stop that - Many ways
-add a reflux/condesor to catch it
-add a watch glass and only fill the vessel 1/3 of the way
-if using a scrubber, add an empty flask before the a-b train to catch values
-let the reaction generate its own heat at first, adding heat near the end of the reaction
Evaporating is different than boiling, while evaporation takes place during boiling, for our purposes that is not needed. Why? Because the bubbles lose values, so slow evaporation is required. Sure, it takes forever and a day to evaporate without boiling, but not if you increase the surface area of the solution being evaporated. I.E. use a shallow wide vessel on low heat -just enough to steam or make tiny tiny tiny bubbles seen on the bottom
I missed a couple points in there somewhere, but hopefully i conveyed the message well enough. Dont over think it, well, do. Do overthink it actually. Just dont focus on the small trivial matters that cost you more money in the end than what they are worth. Theres a saying for that. But i can't think of it right now.
Time for more coffee
Here is very crude way to condense vapors. It works well when heating short of the boiling point. I have added ice at times, but not very often as the extreme cold could break hot glass. The glass bowl is a candle holder.
jason_recliner
Well-known member
"The stingy man pays the most." - Irons.Topher_osAUrus said:
