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.
Ore Refineries are critical in gaining funds for the army at many stages of the game, especially early on. While expensive, each refinery provides needed access points for miners to dump ore and gems, giving their commander a potentially steady income, depending on how far away and how many there are.
As an added benefit, every Allied refinery comes with a Chrono Miner, so placing one near ore will give an immediate boost to the Allies' economy. Incidentally, because these buildings come with a miner, depending on the situation it can be more beneficial to build and sell these buildings to quickly increase miner counts, though do keep in mind Refineries only sell for $300 since they pay for the miner.
Commanders should be sure to make sure that this building has proper protection, from both attacks that try to cripple their economy, and infiltrators seeking to steal $5000 from detector-less refineries; either of these can seal defeat against those unprepared for it.