HARVESTING potassium salt from vast evaporation ponds and more than 60km of canals in the Western Australia gold fields might not be sexy at the moment as investors focus on the gold samples pouring out of drills turning all over the Yilgarn, but “SOP province” builder, SO4 CEO Tony Swiericzuk wasn’t being sheepish at this year’s Diggers & Dealers. “You can’t eat gold; you can’t eat iron ore,” he says.