Ordan is a dwarf who works in the blast furnace factory on the east side of Keldagrim, the dwarven capital city. Ordan runs the Ore Seller shop, which stocks a variety of ore that can be used for smithing. He is a popular destination for players smithing at the blast furnace.
Ordan's shop is stocked by dwarven miners that arrive through the use of the mine cart transportation network. Ordan can also un-note all your noted ores (up to mithril) for a price. About every minute, a dwarven miner will arrive and re-supply Ordan with a single type of ore. His maximum stock for each type of ore is 100.
Ordan sells ore at a variable rate based on GE Market prices.
Based on this information, if you use the shop interface to un-note your ores, it is beneficial to keep stocks very near 100.
When playing the blast furnace, do not rely on the restock rate for your ores. It takes a very long time for ores to restock. Likewise, do not sell many more than 100 ores, as they will slowly decrease.