jonrms said:
That was the most helpful reply I received. Thank you. Although I think I might pass on the electrolyte contraption. Drilling a hole or cutting it with would work well.
Your 100% correct about the lack of nitric acid. Yes making the acid is easily done but I am not for breaking the law.
Poor man's aqua Regis here I come... soon. Lol
I think I may have caused a bit of confusion in that reply.
Forgive me, I will try to clarify.
-poorman AR will work, sure. But, the amount of waste generated will be immense. The cost in acid will be quite high, and the cost of waste treatment will be proportional to that cost factor also.
-"But you said 1 gallon of acid dissolves 2 pounds of metal" -you say in turn.
--correct, but, using poor man AR the sodium nitrate needs to either be dissolved in watet first, or it needs to have a low molar acid solution that it is put into so it can readily dissolve, which in turn will quickly create your nitrosyl chloride (the workhorse of AR)
My third suggestion (the best, most practical, most economic solution!) Was to use it in you stockpot.
-"whats a stockpot?" -you say?
Well, when we dissolve (just for example) some old pentium pro cpus in AR, we remove the excess nitric acid, then chemically reduce the gold out of solution (precipitate the gold, colloquially) because of whatever reason not 100% of the gold will precipitate with your reducing agent. Also, if there are trace amounts of platinum group metals in that solution too, they need to be recovered. It doesnt make sense to chase after a few pennies of platinum with $50 in chemical reducing agents, so we need to have a clever way to reclaim them in a manner thats more frugal (shoutout to dave
).
-"What way is that"- you ask?
Well, that way is the stockpot. It is where we put our acid solutions that have
traces of values still in solution. In fact, any and every solution that
has the potential to dissolve gold, I treat through a stockpot.
-"What is it?"
Well, to answer that, we need a little background on how metal ions in solution behave. For that, we only need to look at the reactivity series of metals. Some really smart guys a long time ago figured out how much electron potential each metal has, and placed them in an ordered scale. So, at the bottom of the list, we have our noble metals. They are quite unreactive, and really dont like being metal salts (being dissolved by an acid, a metal becomes that acid metallic ion, copper in nitric-copper nitrate, copper in HCl-copper chloride, copper in sulfuric-copper sulfate)
Above the noble metals we have mercury, silver, copper. This is important.
-"why"
Well, its important because the metals higher in the list want to be a metal salt more so than the ones below them. So for instance, if we have gold dissolved in AR, we can place a piece of copper in there and the gold will displace the copper into solution, while the copper will reduce the gold back to metallic gold.
So, the long long short of it is.
The stockpot is the best way to go about it, because your bars will be dissolved by waste acid (That was already used to recover or refine gold), and the gold and other noble metals will be recovered for free basically. So, the next lots of PC scrap you get,
dont melt them, separate and process them accordingly!
I could probably write another 15,000 words on the reactivity series, stock pot, and much much more. But, I think what will help you the most is directing you to a place where you can make these discoveries on your own. We learn much better when we fit the pieces of the puzzle together ourselves. So, I suggest going to the library section of the forum and finding CM Hokes "Refining precious metal waste" which is a free pdf book that has be generously posted by numerous members. In it, you will get the fundamental principles you need to understand the reactions and the lingo. It is written for everyday guys like you and me.
If paper is more your fancy, I quite like CW Ammens "Recovery and Refining of Precious Metals"
It lays out what a beginner needs to know, what he needs to have in his lab (as far as reagents and equipment, etc), goes over assaying and testing techniques. --Its solid, rock solid--
Theres tons of other literature I could suggest too, but, most important is this forum. It can teach you everything you need to know, you just have to know what to look for. Those books referenced will also help give you the wisdom to know what to look for. Also, take the guided tour, it is a bountiful cornucopia of information.
Too long, didnt read?
-dont use AR, use them to cement out your stockpot, read Hoke.
Edit,to fix a letter
