FWIW, here's a graph of the IsaMill grinding machine's relative...

FWIW, here's a graph of the IsaMill grinding machine's relative efficiency, taken from IsaMill's website. Note that the vertical scale in particular is logarithmic.

Also of interest from that page: "Comminution consumes 14% of all electricity generated in Australia, and up to 4% world-wide" (Fuerstenau, Berkeley University, 2003) and it is "responsible for 50% of total mineral processing costs" (Wills, 1992)

"Media selection has a major influence on mill parameters such as energy efficiency, internal wear and operating costs. With the introduction of economic ceramic media the energy efficiency of IsaMillsTM increases dramatically."

BTW, there doesn't seem to be anything particularly experimental about the use of these mills. At last count, there were 86 IsaMills in service world wide.

Note that I'm just regurgitating Xstrata info. I'm not in a position to verify or contradict their claims for the IsaMill technology.