A milling device for excavating mining materials is disclosed. The milling device comprises a milling drum rotatable about a drum axis; a first group of excavating heads arranged around a periphery of the milling drum and driven to rotate about a first rotational axis extending substantially radially to the drum axis; and a second group of excavating heads arranged around the periphery of the milling drum and rotatable about a second rotational axis extending substantially radially to the drum axis. The first group of excavating heads includes a plurality of first excavating tools configured to perform a first, cutting operation, and the second group of excavating heads includes a plurality of second excavating tools configured to perform a second excavating operation different from the first, cutting operation.
