South Korea purchased 6,000 tonnes of aluminium and 200 tonnes of nickel via tenders, the state-run Public Procurement Service said. It also issued tenders for a total of 3,000 tonnes of grade-A copper cathode of London Metal Exchange (LME) registered brands with a purity of more than 99.99 percent for shipment by June 15 to the port of Incheon. Registration for the copper cathode tenders will close at 2 p.m