https://www.smh.com.au/business/companies/nice-and-dirty-rio-s-new-mine-taps-aluminium-boom-20190308-p512mm.html
Canyon has more resource, higher quality and very low grade silica.
It has not yet fully drilled or explored its resource.there will be more drilling results to come.
It will also be more cost effective to build and mine in Cameroon, than Rio could be in Oz.