To protect domestic industry from cheaper metal imports from countries like China, the Mines Ministry has asked the Finance Ministry to hike import duty on aluminium to 7.5 per cent. The import duty on aluminium is 5 per cent at present. “The Mines Ministry has written to the Finance Ministry to hike the import duty on aluminium to 7.5 per cent from 5 per cent,” Mines Secretary Balvinder Kumar said.