Refractory ceramic formulation, and a refractory ceramic product

Refractory ceramic batch comprises: a mixture comprising at least 70 wt.% magnesia, at least one flexibilizer in the form of spinel, hercynite, galaxite or jacobsite, and at least one phosphorus-comprising component; another mixture comprising calcium oxide and silicon dioxide, where the mole fraction of calcium oxide is more than twice the mixture as high as the mole fraction of silicon dioxide in the mixture. An independent claim is also included for a molded refractory ceramic product which is produced from the batch by a ceramic firing comprising magnesia, at least one mineral phase that has formed from at least one flexibilizer, and at least one phase made of tricalcium phosphate or calcium-silicate-phosphate mixed crystals.