Metal ore is a waste byproduct produced by mines. Mines produce 75% pure ready to use metal and 25% ore. Ore is useless, but can be converted into pure metal by smelter units. Some races can not build smelters, for them metal ore is completely useless. The Privateers are one race that does not have the ablity to build smelters.
Mines can act as light duty smelters if you have one or more mines on a base they will process a total of 30kt of ore a turn for free. Mines will only do this for you if your race has the abilty to build smelters.
Metals exist in the core of most planets. The density of the metals governs how fast the metals can be extracted from the core.
Some ships have ore processing devices that can convert ore into metals.
Also See: How Do I Mine Metals
Sept 4th, 2003