Since there’s a possibility of propane/gas left in the tank, many landfills, recycling centers, and scrap metal dealers will not accept unwanted tanks for recycling.
Couple of suggestions:
If you have a propane tank that you don’t want, place your old tank beside a Blue Rhino display and they’ll take care of it.
Baker's Gas & Welding Supplies and Baker's Propane in Tecumseh may accept empty propane or other cylinders.
Contact another welding supply store.