Combine the rice, salt, and 2 cups of water in a medium saucepan over medium heat. Heat to boiling. Reduce heat to low, cover, and simmer 20 minutes. Meanwhile, grate 1 tablespoon peel from one of the oranges. Then cut off the remaining peel from both oranges and cut into sections. Cut the onion into thin slivers. When rice is tender and the water is absorbed, fold in the 1 tablespoon of peel, the orange sections, onion, mint, olives, and olive oil. Season to taste with additional salt if necessary.