I am getting to the part where I need to neutralize the nitric in the Aqua Regia.
I have looked at many if not most of the AR threads here at GRF. There seems to be consensus that 'it works good' to add a prill (or more) of nitric, before adding the SMB.
First to test for the presence of Nitric. Also, to neutralize it. I think I have seen threads where both applications are discussed.
So ... I need to buy some Urea.
I am reading about farm-grade urea having crap in it. I don't want to jinx myself by using impure ingredients. This is an example of what they have at Amazon in this grade -
http://www.amazon.com/Urea-NH2-46-0-0-Fertilzer-Pounds/dp/B0054PA524/
The Amazon cosmetics grade - $23.60 for a pound - seems pricey. But this part I like - "Cosmetic USP Grade (99. 8% pure)"
http://www.amazon.com/MakingCosmetics-Inc-Urea-17-6oz-500g/dp/B0051UWL1K/
Then there's the Jacquard Urea. For Dying stuff. $8.26 per pound.
http://www.amazon.com/Jacquard-Urea-1-lb/dp/B0009IL24G/
"Jacquard Urea is a humectant, attracting moisture from the air, keeping the fiber damp longer allowing a greater reaction time for the dye. Used with sodium alginate thickener when printing, painting, directly applying procion dye to fiber or is added to procion dye for super intense color." - I wonder if the sodium alginate is part of this variety of Urea ? Hard to tell from the wording - it makes it sound like a separate material.
More Fertilizer urea - I like this because it has identifiable prill-looking things and it looks clean.
http://www.amazon.com/3LBS-Nitrogen-Fertilizer-Urea-46-0-0/dp/B005IAXN2Y/
Anyway, I'm leaning towards the last one but I'm very open to suggestions. I needed to buy some Glycerin and a better scale so I was thinking about getting it all from Amazon.
