Bishnu Dash Iron ore exporters in Orissa want the Centre'to exclude transportation cost from the 15 per cent ad valorem duty impose last month. Exporters argue that the transportation cost accounts for more than 60 per cent of the total value of iron ore exports. Earlier, a specific duty of Rs 300 per tonne was imposed on export of iron ore lumps and fines with over 62 per cent iron content, and Rs 50 per tonne on lower grade ore. Under the new policy, exporters are required to pay 15 per cent on the total value of the ore being shipped out.