Making your post using your best writing skills, and using the helpful tools like spell check, will make your post much easier to read, which will assist those reading, the easier to read and understand the better for all of us.
You are getting a general idea of the problems you have had and what went wrong up to this point.
Silver, why do you suspect silver here where from solder?
Carbon can reduce gold, but here it is just a possible contaminant from dirty glassware, oil, organics or coatings on pins, or organic materials like bugs or fallen leaves in your reactions, although a source for problems, here carbon reducing gold is not the problem.
Some of your used solutions can be reused in recovery processes or be used to make other reagents or chemicals for use recovery or refining, it depends on what they consist of.
We can discuss possibly reusing some of your waste acid solutions later.
But, at this point lets discuss:
Waste treatment.
The reactivity series of metals and how the reactions displace other metal ions from solution.
Cementing gold from solution.
Testing for gold and identifying other metals in solution.
Working safely with the deadly gases produced, protecting ourselves and others from the toxic chemicals generated, Basically using safe lab practices.
Gaining an understanding of the reactions we expect, and understanding the problems that can and will follow, also gaining an understanding to be able to figure out our problems and correct them when they poke out their ugly heads.
Choosing methods to prepare our scrap for recovery.
Choosing a recovery process, and understanding its chemistry.
Dealing with problems of the recovery process chosen.
After getting a handle on the recovery of the gold, maybe then we can go on to discuss a little about refining the recovered gold.
You are on the right track, just stick with it, do not let the gold fever pull you off course, jumping in experimenting without gaining an understanding of the basic principles needed to be successful.
Gain the understanding, then use your understanding to experiment, and improve that basic understanding...
Grammer, and spell check, can only improve our communication, making it easier for us to help each other as we share our experiences, and new found understanding...