In a large bowl, combine beans, rice, ketchup and spices. Mash with a fork potato masher until beans are well mashed. (Rice will be lumpy.) Add remaining ingredients and mix well. Divide mixture evenly and form into 8 burgers, 1/2 to 3/4-inch thick. Wet your hands slightly to avoid sticking. Lightly oil a nonstick griddle or skillet, or spray with a nonstick cooking spray. Preheat over medium heat. Place burgers on griddle and cook until browned on both sides, about 15 minutes. Turn burgers several times while cooking.