铁矿 covers both the raw material (iron ore, the rock) and the place where it's extracted (an iron mine). Context disambiguates:
进口铁矿 = importing iron ore;
关闭铁矿 = closing an iron mine. For other ores, swap the metal:
煤矿 (coal mine),
金矿 (gold mine),
铜矿 (copper mine).
