To make salad, bring a medium saucepan of lightly salted water to a boil. Add rice and cook (like pasta) until tender, about 16 minutes. Drain in wire sieve, rinse under cold water, and let cool.
In medium bowl, whisk orange zest and 2 tablespoons orange juice, 1 tablespoon vinegar, 1/2 teaspoon salt, and 1/4 teaspoon pepper. Whisk in oil. Add cooled rice, black beans, scallions and cilantro, and mix. Let stand and room temperature for up to 4 hours. (If refrigerated, let stand at room temperature for 30 minutes before serving, or rice will be hard.)