The National Aluminium Company Limited (NALCO) has achieved yet another milestone by completing its 501st shipment of alumina from Visakhapatnam Port.To mark the occasion, a special function was organized at the WQ-5 Berth at Visakhapatnam Port at which Chairman of Visakhapatnam Port Trust pressed the hooter to mark the completion of the 501st alumina shipment.Srivastava handed over the shipping documents to the representatives of M/s Alaska Metals of Switzerland, the buyer of the shipment, a company release here said today.Since inception Nalco through Visakhapatnam has exported 13.70 million tonne of alumina, and 1.04 million tonnes of aluminium.In 2009-10, the company exported 702,554 tonne of alumina, 146,947 tonne of aluminium and registered an export earnings of Rs.2,209 crore.