The first round of China’s much-anticipated state metal reserves auctions needed only one of two days allotted for all the copper and aluminium on offer to be sold, notices on the bidding platforms and two industry sources said.In a rare move aimed at cooling a rally in metal prices that has pushed up raw material costs for Chinese manufacturers, the National Food and Strategic Reserves Administration said last month it would sell 50,000 tonnes of aluminium, 30,000 tonnes of zinc and 20,000…