I have a heel spur on the calcaneal bone. Will extracorporeal shockwave therepy rid the spur? How many sessions?

No. Eswt can help get rid of the pain you are feeling, but it does not make the bone dissolve or disappear. How many sessions would depend on if it is high energy or low....Hogh energy typicallly one maybe 2 sessions, low energy can be 3-8. (these are averages and realize it doesn't always work.).
No. Shockwave therapy does not breakup bonespurs. It creates new tears in the fascia that is causing your heel pain. As these new tears heal with thethe increase in bloodthe flow they will help the old ones heal as well. At least that is the theory.