Grae said:
Do you have anything that can help me out with the chemical to "things to be processed" ratio?? I just need something to help me figure out a starting point.
jimdoc gave some very good advice, nothing substitutes for serious studying. I very seldom run "whole boards" in AR although I may run them in AP depending on the specific board. If you have gold plating on the boards and not the very thin enig type, with AP you can see your gold as it comes off. This helps avoid loosing your gold (even if just from your sight) and avoids the panic it can cause. I use a very basic idea that one gallon of AP can remove two pounds of base metals, but will slow down as it becomes saturated. For a gallon of hydrochloric I add about 2 or 3oz. of 3% peroxide, add a fish aquarium air pump and forget it for a few days. It is a slow process very well suited for beginners and keeps things simple. It is also good to have on hand as I put pieces of boards and other items in it long term that is not worth processing on their own. During the wait I had more time to read and study for the next steps I would need.
AR is another thing and gets more complicated fairly quick, even though it don't appear that way. A starting point might be useful, but only when you understand the reactions and how they work a bit better. I am constantly learning new things about AR as I always seem to find new problems as I try new materials. I basically start with just enough hydrochloric to cover the material then add small amounts of nitric spaced out over time until the materiel goes into solution. While this sounds simple it can become overwhelming fast for the beginner. It is best suited for refining the recovered gold from AP but can be adapted as one learns more about it and how to judge what is going on in the reactions. It is very easy to add way to much nitric to AR because we get in a hurry sometimes, especially when first starting out. This is the reason for using sulfamic and not urea in many cases, to avoid some of those problems. I still have dirty solutions, usually from copper based materials that seem to be very annoying to kill the excess nitric from. Here is where heat is your friend so long as it isn't over done, don't boil, just below boiling over a period of time works best. If you add sulfamic to hot AR be very, very slow as it will foam over the sides easily when mixed hot. Use an excessively large container to help avoid the problem. If you need 500ml of solution use a 2000ml container. I have not used urea so I am not sure if it reacts the same way.
And all of this needs to be done away from friends, family and any pets or livestock you may have. Keep in mind you fit into one of those groups somewhere as well
. The resulting material is toxic and needs to be handled as such, always.. ALWAYS. This is why there is a whole section on safety and disposal of used chemicals. It is a very good place to actually be studying from the get go as you will need it if you mix the chemicals to try this. None of this stuff is safe to just dump on the ground or down the drain.
One more piece of advice, ask before trying. It is always easier to avoid a mess than it is to fix a mess.