The Ore Refinery is a technologically complex building completely outfitted to receive and process raw ore from miners, and instantly converts them into usable funds for commanders. This makes this structure a vital asset to any base economy.
Replacing the Slave Miner from the vanilla game in favor of more traditional Ghost Miners, the Epsilon Ore Refinery is not unlike the other Ore Refineries; it is essential in order for their Ghost Miners to deposit the precious ore and gems required to begin and maintain the production of Epsilon's unorthodox armies and foundations. While there is no limit to how much a proselyte can store ore (and in turn, funds), additional Refineries should be constructed if the Ghost Miners become too numerous that they have to wait until the Ghost Miner unloading the resources, or if the proselyte has recently acquired a Tech Base Expansion Post that is close to an ore/gem field so that the money keeps flowing.
Even though Ghost Miners are normally invisible, an enemy commander can notice their presence near the Epsilon Ore Refinery if smoke suddenly comes out of the exhaust pipes, indicating a miner has deposited ore into the refinery.
Unlike the other factions however, the Epsilon's economy is not easy to disrupt, as even if their Refineries are destroyed, they are able to turn units (whether mind-controlled or loyal to Yuri's cause) into resources via a Grinder.