Excuse my while I go bang my head against the wall!
This is exactly the problem with e-waste, it varies depending on what you feed your system. So how can you answer the question?
Years ago, when the classic fire assay books were written, the variety of metals the assayer would likely see were limited. Interferences caused by some component of a sample were usually worked around by fluxing or scorification and the chances of having a wide variety of interferences in one sample were rare.
Fast forward a hundred years, e-waste enters the scene. Exotic metals, precious metals, and rare earth metals all woven into a mixture that was never something Mother Nature would ever think of putting together.
There are some metals which will be left with the slimes in the copper electrolytic circuit and there are some that will degrade the electrolyte to the point where it has to be replaced. If your dore bars are of the type that are collected in the anode slimes then the copper refiner is a happy camper and his process is made for your scrap. But if you have a lot of un-desirable metals which will degrade his system, he is forced to dilute these elements with other copper waste to make a blend he can deal with. In effect dilution of the bad actors so the electrolytic system can handle them.
Your dore bars are likely to vary with what you process and your rates will vary with what you mix in. The only way around this is to know what you are adding to a melt and this comes from running complete analysis of your dore bars and comparing the results to what went into the melt. Developing this type of database is critical to finding a refiner to cost effectively process your material.
There is a certain level of processing e-waste you can aspire to and beyond that I am inclined to confess you will need to learn some analytical chemistry. Experience on an AA or ICP is much more important for e waste than any other type of mixed dore bars.
I see a trend in refining to process a material to a certain point and quantify it and send it to a refiner who can process the material cost effectively. Unless you are getting tons of a specific material setting up for the final recovery may be fruitless. The industry is changing, e-waste is evolving even catalysts for converters is facing challenges. There is a process of adding a rare earth oxide Cerium(III) Oxide to the catalysts which helps prevent the catalyst honeycomb from clogging up. The cerium can be recovered if the catalysts are leached but not if they are smelted. So depending on how much the Cerium value per converter is worth, that may change the way catalysts are handled in the future.
The one thing that will remain constant is good sampling and analytical chemistry.
