After an x-ray told pain in my ankle was caused by calcification of an old injury (10-15 years old). will it cure naturally and when can i run again?

Doubtful: If the injury occurred that long ago and there is calcification that is causing local irritation and inflammation enough to cause your current symptoms, it is unlikely this will just go away on its own.You need to talk to an orthopedist, preferably an ankle/foot specialist about treatment options. They may be able to do some local injections, try some anti-inflammatory meds and/or discuss surgery.