ovidiuanghel,
I have to agree that the tiny amount of values from that material most likely cemented out of your leach onto those circuit boards, and this solution may not have much gold if any.
I suggest, after recovering any solids from the cementing process, save the rinsed powder and store in a small container, treat this solution for waste using the instructions found in the post dealing with waste found in the safety section.
Start spending time collecting scrap as you study, collect enough scrap to work with (large batches), spend time separating the scrap by type of material, preparing it to be processed (like cutting fingers off of computer memory), read and study Hokes book, work with the experiments in her book to get a good understanding of how the different metals react with acids.
Do small experiments testing for values in solution, prepare and teach yourself what to expect and how to recognize what is going on in these solutions.
Reading the forum you will see how to prepare your scrap material to get the best yield from what you process, what process works best for what type of materials you are dealing with, you will also see that the materials are processed separately, and how they are prepared before the see the acids, how whole circuit boards are just a way to lose values, or how solder and tin can trap your gold taking it away from you, and so on.
I suggest start out learning with memory fingers, these have the least variables for mistakes, or lose of value's, like when you work with several different kinds of base metals, or working with large pieces of hard to dissolve metals where you may leave gold on undissolved base metals that would cement your gold out onto them, or hidden copper or other base metals that can cement out your gold in the leaching process like the copper traces under layers of solder mask or in the center of circuit boards under the fiberglass layers, or from solder and the gold being stolen from you by the tin in solutions.
Work with these memory fingers like a scientist would work with his controlled experiments, where working with a more pure metals will not give much trouble, and you can learn what to expect, and get an understanding of the chemistry involved, before working on the materials which would give many variables in the process.
Working with the finger foils you can learn the basics easier as there are not as many thing that can mess it up you can also get an idea of how much of these gold foils it takes to make a little bit of bold precipitated powders, or a tiny button of gold, learning and experimenting with fairly clean materials and metals in these acids will help you understand, what to expect, and what is going on when the recovery process is not full of variables, work with this material and study until it becomes easy, by then you will have more material that may require a different recovery procedure but with the same basic idea, then study what you need to and you will have some experience on what to expect while recovering values from the scrap.
Do not worry about getting gold just yet, spend your time on educating yourself, the gold will come and your education will prepare you to know how to deal with it when it does come your way, the education will also teach you where to find that valuable scrap, and how to keep it coming your way.
