Orichalcum ingot is a crafting component introduced in the Blood and Wine expansion and can be dismantled into orichalcum ore.
Needed to craft:
Dismantle from:
- Orichalcum plate
- Toussaint armor (magic)
- Toussaint trousers (magic)
Crafting Requirements 
It can be found in the reward chests for two treasure hunt quests, Applied Escapology and The Black Widow, in a few guarded treasures and bandit camps, or purchased from the following merchants:
- Armorer in Hauteville
- Blacksmith in Belgaard Manor, after he is rescued
- Lazare Lafargue in his workshop
- Trentin in his workshop in Hauteville