The mineral wool is rated at 1000 Celsius. I was maybe thinking the refractory cement would absorb most of the heat and would affect the mineral wool that much.
I found a of 4mm thick sprinkler pipe about 22cm in diameter and about 50 cm tall for a gas forge. I plan on lining it with wool and then refracturary cement. My question is could I use mineral wool or does it have to be ceramik wool?