5 ms·

I'd assume any ppm needs to be corrected by an "economically accessible" factor much <1. After all, we're not running the entire crust through a separator and e

by ethbro 9y ago

I'd assume any ppm needs to be corrected by an "economically accessible" factor much <1. After all, we're not running the entire crust through a separator and ending up with piles of its different constituents.

bryanlarsen 9y ago
"we're not running the entire crust through a separator and ending up with piles of its different constituents." We're basically already doing that for copper.
- philipkglass 9y ago
  The lowest mine reserve copper grade I see reported for any of these big copper projects is 0.25%, for Morenci: http://www.mining.com/these-10-mines-will-set-the-copper-price-for-the-next-decade/ http://www.mining.com/these-10-mines-will-set-the-copper-pri... That's 2500 ppm Cu, significantly higher than the crustal average of 50-100 ppm. If resource concentration isn't important, why don't miners just locate for low-cost infrastructure and extract copper from whatever rocks are close at hand? You could certainly save costs on workers/power/water/transport over going way off into the Andes or the Atacama Desert to extract ore. Likewise, if resource quality doesn't matter to platinum production, why not do the same for the platinum group metals? Just locate your multi-metal production complex wherever power and labor are cheap. If resource quality is unimportant, China should be a bigger platinum producer than the US or Canada. As far as I can tell, the only element ever commercially mined from ores of sub-ppm grade was radium. It was also by far the costliest substance ever produced by mining operations. (Some sub-ppm element concentrations may be exploitable when those elements are secondary, as with iridium as a byproduct of primary copper/nickel production.)
  - bryanlarsen 9y ago
    We're closing in on only a single order of magnitude difference between the concentration of copper in a copper mine and the concentration of copper in random crust. Considering that you used to be able to find pure copper deposits, I think your data supports my point.

by ethbro 9y ago

bryanlarsen 9y ago

"we're not running the entire crust through a separator and ending up with piles of its different constituents." We're basically already doing that for copper.

philipkglass 9y ago
The lowest mine reserve copper grade I see reported for any of these big copper projects is 0.25%, for Morenci: http://www.mining.com/these-10-mines-will-set-the-copper-price-for-the-next-decade/ http://www.mining.com/these-10-mines-will-set-the-copper-pri... That's 2500 ppm Cu, significantly higher than the crustal average of 50-100 ppm. If resource concentration isn't important, why don't miners just locate for low-cost infrastructure and extract copper from whatever rocks are close at hand? You could certainly save costs on workers/power/water/transport over going way off into the Andes or the Atacama Desert to extract ore. Likewise, if resource quality doesn't matter to platinum production, why not do the same for the platinum group metals? Just locate your multi-metal production complex wherever power and labor are cheap. If resource quality is unimportant, China should be a bigger platinum producer than the US or Canada. As far as I can tell, the only element ever commercially mined from ores of sub-ppm grade was radium. It was also by far the costliest substance ever produced by mining operations. (Some sub-ppm element concentrations may be exploitable when those elements are secondary, as with iridium as a byproduct of primary copper/nickel production.)
- bryanlarsen 9y ago
  We're closing in on only a single order of magnitude difference between the concentration of copper in a copper mine and the concentration of copper in random crust. Considering that you used to be able to find pure copper deposits, I think your data supports my point.