How to drop gold from sol using urea to neutralize sol to ph

[Johnny Williams]

I have two bottles, one blue (silver) and the other dark tan (gold).
My question,to drop gold from the dark tan sol,how much urea is added to neutralize ph to ~1.0? When I took a small amount of the liquor, in a watch glass and added a sprinkling of urea, a white material droped and wouldnt go back into sol. What am I doing wrong. Newbie

 

[kdaddy]

Wait....am I being Punked....where are the cameras???? You don't drop gold with urea. You should stop whatever you are doing and read more, the search function is very useful.

 

[Johnny Williams]

May be I spoke using the wrong term. The urea is used to neutralize the excess nitric acid ,not the dropping of the gold. It is difficult to measure the ph using a ph meter,because of the sample size.

 

[kdaddy]

OK, so what is your "REAL" question?

 

[Johnny Williams]

My REAL question is how is the urea added ,in small amounts, so as to not have any precipitate then add the SMB?

 

[philddreamer]

You jumped the gun, Johnnny! You started a process without knowing the do's & don't, & now your stuck. That's why we recommend always to read, read, read before you start any process...
What is the source of the PM's?
What is the blue solution, silver nitrate? Did you inquart?
What is the tan solution, AR? Did you test it for gold with stannous solution?

If its AR, did you add too much nitric? Did you evaporate the nitric?
There're still a lot of detailed steps to follow, before you add the SMB.

Take care & be safe!

Phil

 

[kdaddy]

I have only used Urea one time and that was before I really knew what I was doing. You are to add a few prills at a time until no more fizzing occurs. I don't know what your white precip is, maybe undissolved Urea. If you are patient and do some more reading
before you try something that you don't understand you will be successful.

P.S. Urea sucks, there are better ways.

 

[goldsilverpro]

Has anyone tried the sulfamic acid (instead of urea) method to eliminate nitric acid that I covered in this post? If so, what do you think?

http://www.goldrefiningforum.com/phpBB3/viewtopic.php?f=51&t=10799&p=105096&hilit=sulfamic+acid#p105096

 

[snail]

I tried sulfamic acid on my last batch of poor man,s AR. I also believe that is superior to urea. Much easier to filter. I will be using it from now on.

Dale

 

[qst42know]

I have tried sulfamic acid. I like the speed it provides as opposed to evaporation.

There were a couple things you mentioned that might be good idea to discuss. Both have to do with when you apply the sulfamic.

From the formula in your post sulfamic produces sulfuric acid in solution, based on this I added it before the solution was filtered and still concentrated in case there was a trace of lead. You also mentioned the solubility of sulfamic. I added this dry to a hot solution that had just finished dissolving the last of a second refine of gold powder. It dissolved quickly in the hot solution. What I noticed was that the solution started bubbling as if it were boiling although the hot plate was off.

I would guess this was the laughing gas being expelled?

As far as determining the end point, though I wouldn't recommend hanging one's nose over the reaction, I did notice there was a distinct change in the odor of the solution.

I did find sulfamic acid available at Home Depot as Grout Haze Cleaner, a bit pricey at $7 for a small plastic tub but I don't need very much anyway.

Chris