iron processing - Ores | Britannica
iron processing - iron processing - Ores: Iron ores occur in igneous, metamorphic (transformed), or sedimentary rocks in a variety of geologic environments. Most are sedimentary, but many have been changed by weathering, and so their precise origin is difficult to determine. The most widely distributed iron-bearing minerals are oxides, and iron ores consist mainly of hematite (Fe2O3),