An American mining start-up gained the powerful endorsement of the U.S. Defense Department last month, when it received a $37.5 million grant to develop what could be the country’s largest graphite deposit, close to Nome, Alaska. The company, Graphite One (Alaska) Inc., aims to be America’s first domestic miner of graphite, a mineral that’s vital for producing electric vehicle batteries and is used widely in the defense sector.  But Graphite One’s fortunes will likely depend on t