use bcln??

according to the Wiki, TTAN has a melting point of 1667.85°C, while ROCK has a melting point of 1670°C, but ROCK will break into STNE at or above 120 pressure.

for a vanilla TTAN melter, I would suggest something made of ROCK, although the gap between their melting points is very small.

Frme insulates heat,cannot catch fire,and does not interact with most other elements.If your problem is slow conduction,use qrtz because it starts to melt at 2300 degrees.

You could probably get away with using CRMC or PSTS and pressurizing it.

crmc+insl

Crmc and insl, if use ambient heat, add a layer of ttan outside of the insl, remember to have at least 2 pixels of crmc seperating where the lava is from the insl

As others have said, yeah pressure-strengthened ceramic is a good idea. You can actually get crazy high melting points with that containment.