If I were you, the very first thing I would do before doing anything else is to pick up a book by C.M. Hoke called Refining Precious Metal Wastes. It's an old book intended for people who knew little if nothing about chemistry, metallurgy, etc. Because the book is out of print, you can download it without any copyright concerns from here.
Refining Precious Metal Wastes C M Hoke
To tell you what you need to refine is more difficult than you might believe. There are so many different processes for recovering precious metals that it can be very confusing for someone first starting out. By reading the book I mentioned above you will at the very least be familiar with the processes to refine precious metals, the equipment and acids needed, the practices employed and the terminology so that you can talk with other refiners when you require help. If you don't for example understand the difference between cementation and precipitation, you will never be able to communicate with someone else about exactly what type of process you are using.
I would also concentrate on one type of precious metal scrap, and start with the easiest at that. For example, gold plated pins are most efficiently recovered on a small scale by using a sulfuric stripping cell, but gold plated fingers are best processed, and inexpensively I might add, by using an etching solution that eats the copper under the gold plating, then foils off the gold plating so it can be filtered, recovered, and further refined. Not only that, but the etching solution you use keeps expanding as it becomes pregnant with copper, thus once started, it's an ever expanding solution that just requires you to either remove and add water, or add water and keep expanding. But even at this, you need to understand how to recover the copper from the solution and then process so that there are no more heavy metals in solution and your PH is neutral.
Which brings me to other issues. If you are doing this, you have to do so in a well ventilated area, outside, under a fume hood, etc. The gases, NOx most noticeably, are extremely hazardous to your health and can cause serious health risks, including death. During the gold rush in California, miners used to call NOx the brown death because it kills. If you are trying to do this in your garage, and you have anything metal including a car, tools, light switches, it will eat the metal and make it look rusty. If you try to build a fume hood out of wood, you could be creating nitrocellulose from the wood coming into contact with NOx gas, which would make it so highly flammable that it could spontaneously ignite without any ignition source.
Sulfuric acid is used in some of the different recover processes, and even to drop lead out of solution during the refining process. If you put one single drop of water in sulfuric acid, it evaporates the water so fast that it causes it to splatter and explode. Enough water and you could splatter the acid all over you, which when it comes into contact with organic material dehydrates it so fast that it turns it to carbon. If you get sulfuric, nitric or hydrochloric acids in your eye it can cause blindness in most cases, immediately.
Read the book, but it's not going to tell you how to process using new recovery methods, so after you read the book you might want to think about what type of material you want to process, then learn the process, read about it until you understand it very well, then try it on a small scale. Where most new hobby refiners get themselves into trouble is that they try to recover and refine large amounts before they understand how to do it properly. Simply things like how to pour, or not pouring water into acid but acid into water instead, can be a total game changer.
If you are serious about refining, you can check out the gold refining forum, which honestly I see as a sister site to this one since it deals with refining and this site deals with scrapping.
Gold Refining Forum.com • Index page.
Be aware if you do not read the C.M. Hoke book before you ask questions on that forum, the very first thing almost everyone is going to tell you to do is to read that book.
I hope I don't discourage you, rather help you realize that the questions you are asking are not easily answered in a single post and maybe encourage you to learn and read before you attempt to recover or refine anything.
Scott
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Originally Posted by BRASSCATCHER
P & M Recycling - Specializing in E-Waste Recycling. 
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