Deep Space Nine the physical space station is built by the Cardassians as an ore-processing facility (named Terok Nor) and used as such until it is taken over by the Bajorans and Federation at the beginning of the DS9 series.
The station has a large ore processing facility near its center. During the time when Bajor and the Federation jointly control the station, is it ever used for its original purpose as an ore-processing facility? Is the ore-processing equipment simply left to degrade in place, or is there an attempt to adapt it to Bajoran and/or Federation needs? Is the equipment removed and the space reclaimed for other purposes (e.g. living areas, hydroponic farms, cargo bays, manufacturing facilities for additional Runabouts, prison space for captured Maquis members, etc.)?
My guess is that the movement of the station from Bajoran orbit to the Denorios Belt at the beginning of the series (Emissary) more or less makes it useless as an ore-processing facility, but is this ever explored?