sulfide ore. if it is of sufficient grade. to get the pgms. 1st a jaw crusher take it down to 1/4 inch then a ball mill take it down to 80% minus 200. next take the slurry and reagents. most are safe to use and most are natural water soluble oils mix them at high speed add a touch of coperous at this time. then use a froth column of size needed to match the output of the ball mill. Repeat until your pgm grade is up to what you need to smelt. you should be able to do this at a few dollars per ton. and its easy to do. head ore gets dumped into the jaw crusher and the concentrated ore settles in to a drum or tank. if it works on a small scale it will work on a large scale. ALL systems will need a safe place to store your waste after its been processed. Roasting makes a problem that will coast millions to mantain. if there is copper in your ore a leach pad will never be economical . if there is free gold with the sulfides you can do one of a hundred gravity methods in combination with flotation . feel free to contact me with any questions... now I have one for you. what are the results of your fire assay? (the only true assay for value of gold / silver.)