Before you can get the quest to meet Vatudun, you need Knowledge on (Shaking, Drying, Filtering, Grinding, Heating, Chopping) - Beginner. You get those through some quests in Heidel. You also need Gathering Skilled 10 or above, and Processing Professional 5 or above.

You get the quest to talk to Vatudun from the Villager working the bellows behind the Arms Dealer in Keplan - Andria.

Der NPC steht in Keplan unten in der Höhle er hat keiner Markierung bevor ihr nicht Verarbeitung Kennerstufe 5 habt und die Vorquest erledigt habt.

He is located in the Keplan Extraction Mill. The mine under the town.

Where are the comments rofl

IDK if the official BDO website is wrong, but i have done all 4 of his quests and i am Master in both Gathering and processing and i still can't obtain Pure Platinum Crystals from him

Edit: after submitting a ticket they removed that part.