Rio Tinto unit born in Death Valley retooled for lithium battery boom

Melbourne

DURING the financial crisis, Rio Tinto Group needed cash and tried to unload its oldest mining business - one that began in 1872 hauling borates salts by mule from Death Valley to make US laundry soap. The company gave up on a sale because no one would pay the asking price. A decade later, the business is poised to be one of Rio's most promising.

That's partly because a borates deposit Rio discovered in the hills of Serbia contains a h…