An overhead hydraulic door closer would be a good solution for your slamming problem. For a large fire door (and width is the most important dimension to consider) you might go for a medium to heavy duty door closer like the GEZE TS4000 or the TS2000NV. For a narrower door; the domestic closers Eurospec F2003 or T2024 would be more economical. You can read about the special features of each of these door closers by clicking through the links. As you mention it’s in your house, the GEZE door closers I mentioned have the option of upgrading to a matching polished cover & arm (can be brass or stainless steel) which you might want to consider.