The facility was constructed by the Imperial Engineering Corps and was one of two vital structures on that planet. Its counterpart was a construction yard in orbit around the planet which was used to produce the Empire's feared Star Destroyers. The ore facility itself was a ground based facility that was situated amid the junkyard planet of Raxus Prime and was used to collect and transport huge amounts of processed ore to the factory in orbit.
The ground based structure made use of hundreds of smelting plants which in turn diverted processed ore to a massive gravity cannon to launch the material into orbit whereupon it was collected by the massive orbital construction facility that used it to build starships.
It was one of the most important Imperial military projects at the time and was protected by an entire legion of elite troops.
After the death of Jedi Master Kazdan Paratus, the planets legion of droid soldiers collapsed into a lifeless pile of junk without the Force to animate them. This allowed the Empire to establish a presence on the world and use its immense resources for the construction of its war machine.
Galen Marek was sent to Raxus Prime once again in order to sabotage the ore facilities gravity cannon in order to send the reprocessed ore at the construction facility in orbit thus destroying it. During his mission, he encountered a member of the Emperor's Shadow Guard who was protected the factory but defeated the guardsmen who was sent flying into the molten ore as it was sent into space.
The ore destroyed the orbital factory and sent a Star Destroyer crashing into the ore facility thus damaging and possibly destroying it.