This way it's only taken me a few hours to mine all the Khorium for my Turbo-Charged Flying Machine. This makes the farming simply a matter of following a line and mining every vein you detect near it on your minimap. With Routes you can then calculate the most efficient route to visit all possible spawn points in a zone, and display that route on the map and minimap.

Gathermate keeps track of any veins you've come across, and you can import data from the Gathermate_data add-on so you won't have to discover everything yourself. I use two add-ons to help me farm it, which are great to have if you're a miner or herbalist anyhow: Gathermate and Routes.

From my own experience of mining like this in Nagrand, I usually get several Khorium veins each time I complete a circle. As long as you keep flying around mining every vein you come across and continue to do so, all the Khorium that repops is usually yours. Given that there are far less people in Outland these days than there were before Wrath of the Lich King, the chances are pretty good that you yourself are the next person to arrive at a vein when it has respawned.

Every Outland vein you mine has a chance of repopping as a Khorium vein.

Simply select a zone and start mining everything there, continually going around in circles. Comment by QwaneriaKhorium Ore isn't that difficult to obtain, it just needs to be actively farmed rather than searched for.

Wowauction eternium ore