siddharta said:
Hello guys,
I am new here and I am thinking to start with gold refining. I have 2 lbs of scrap CPU-s.
I've done my homework and read all books that you are recommending, but still I have some questions.
What type of processors are you talking about, ceramic, transitional or fiber?
When pins are removed does it make sense to grind CPU-s not to dust but quite small parts? I was thinking to use old steel meat grinder.
It depends on what type of CPUs you are talking about. If you are talking about ceramic processors, grinding them wouldn't hurt and if there is any gold container inside you would get at it. If you do this, you might want to get a classification screen, grind up the ceramic into powder and screen for small wires, but honestly you probably won't find anything more of value. Usually, breaking the CPUs up into 5-10 parts each, so long as the heat spreader has already been removed, is enough. If they are ceramic, a common practice is to remove the gold plated heat shields and process them in a sulfuric cell.
If you are talking about fiber CPUs, if you remove the gold pins first then you could grind them, however, if there are values they could become mashed against your meat grinding blacks. In ceramic this doesn't happen in the same way. But if there is gold in your fiber, you very well could mash it into the fiber/plastic material. Incineration works, but you are also talking about potentially creating toxic gases I don't believe your neighbors would appreciate very much.
Regarding mobile boards I have same question. Process them whole or grind them and then put in AR?
There are different ways to process materials, each person seems to have their own way of doing so. With cell phone boards you are probably going to want to remove the components first. You can do this by dissolving the base metals in acid, then remove the components, or you might use a method that uses heat to melt the solder so they can be plucked out that way. But grinding them up is not going to help. There are not gold wires in the boards. I am using a press with a large case hardened steel vice. I load the cell phone board in the vice and use the press to force the board through, sheering the components off the board, only problem is that material will get flung all over the place if you do not have a way to prevent it from doing so. It's a quick dirty way of removing components. Then you remove the base metals and process in AR to foil. Often when the base metals are removed, some of the gold plate foils off. There is a ton of information how to process this type of material on this forum.
And one final question... Fumes produced in AR process. Can they be exhausted directly to the air?
Thanks, B.
Remember, any gases produced could be life threatening. Keeping this in mind, people do process outdoors where there is plenty of fresh air and ventilation. NOx can be deadly, and any gases you create in the process should be treated as being so. Obviously you don't want to do this in an area where the gases can blow into your neighbors open window. But the gas can be, and is often times, expelled into the air. There are also ways to scrub the gases you produce, small versions of larger systems based on the same concepts, that work very well. Whatever you do, don't process your material near anything metal or alive. It will corrode metal, and kill living things that breath it in. I would strongly suggest that doing this inside is extremely risky and dangerous. Do it outside or under a fume hood.
Scott
