Too late here, clearly my brain was not working correctly.
IMC gets 25% of Sandong. IMC owns 55% of the APT processing plant. If the profits are the same at each stage, then Woulfe would receive (.75 + .45)/2 = 60% of the profits made through the mining and processing value chain. Reading the PEA was not sufficient to determine the breakdown of profits in mining versus upgrading to APT. This net end percentage obviously goes up if there are more profits in the mining part versus processing.
Anyone shed some light on this line of reasoning? Is Woulfe's share of the NPV of Sandong really just ~60% of the NPV?