I tripped over this video. It's six years old but I don't recall it mentioned here on the forum. It's 12 minutes on how a German company makes their crucibles in size up to tons of melt. A lot of dirty manual labor but also big machines and an insight in how crucibles are made.
Crafting Crucibles at Morgan MMS in Germany
https://www.youtube.com/watch?v=QIJhyw8a650
Göran
Crafting Crucibles at Morgan MMS in Germany
https://www.youtube.com/watch?v=QIJhyw8a650
Göran