Mining tycoon Robert Friedland said he’s fielding “unconventional interest,” including from US Big Tech, in Ivanhoe Mines Ltd.’s fast-expanding copper exploration project in the Democratic Republic of Congo, highlighting growing anxieties about future supplies of the key metal. Friedland founded and chairs Toronto-listed Ivanhoe, which on Tuesday announced Bloomberg Terminal that a drilling campaign has increased the mineral resource estimate at its Western Forelands venture by 30% to 12 million tons of contained copper. The company already co-owns a nearby operation in the Central African nation which has become one of the world’s largest producers of the metal.