You have asked a very complicated question as it depends on so many variables.
What sort of scrap is available ?
What quantities are available ?
What type and grade of scrap is it ?
How much will it cost ?
How experienced in recovery and refining are you ?
Cost of and availability of chemicals ?
What can you sell the refined metals for ?
Cost of transport and stripping down the scrap ?
You need to be able to answer all those questions before setting anything up, if your new to this hobby/ business you need to learn all the methods and processes and be able to value the waste electronic scrap you are offered, this takes a lot of time and study, you can buy and sell at a profit if you can find a buyer who you can trade with but to open a refinery is a step too far in my opinion unless you really know your market, the processes needed to recover and refine the scrap and be able to buy knowing what your returns should be.