Sorry if I am hard on your bio-leaching dreams. Research work on bio leaching is still being carried out for various nickel sulfides so one day it may happen. However, right now as far as I know, nobody is close to proove the technology on a pilot or commercial scale. Since such technology is pretty ore specific, even after (if) reaching much more promise, it will have to be tested on the actual ROF ores. Those things take years.
Bio leaching was fairly hot about 15-20 years ago, but has not really gained much since that time. I don`t think Vale or Xstrata do much in that regard for the time being. So any planning NOT or anyone else are making for processing their ores will at least over the next 10 years involve standard and proven technology, and not bio leaching.