Process of coating a refractory body with boron nitride and then reacting with aluminum

Claim 1

THE PROCESS OF FORMING A CONTAINER FOR CONFINING MOLTEN ALUMINIUM AT ELEVATED TEMPERATURES ON THE ORDER OF 1200* C. AND ABOVE, WHICH CONTAINER IS ALSO RESISTANT TO ATTACK OF ALUMINIUM VAPORS AT SAID ELEVATED TEMPERATURES, THE PROCESS COMPRISING THE STEPS OF FORMING A SLURRY CONTAINING BORON NITRIDE POWDER, APPLYING A LAYER OF THE BORON NITRIDE SLURRY TO THOSE SURFACES OF A CONTAINER FORMED OF A REFRACTORY MATERIAL SELECTED FROM THE GROUP CONSISTING OF CARBON AND THE REFRACTORY OXIDES AND SILICATES WHICH ARE TO BE EXPOSED TO ALUMINIUM AT SAID ELEVATED TEMPERATURES, DRYING SAID BORON NITRIDE LAYER AND THEREAFTER REACTING SAID BORON NITRIDE LAYER WITH ALUMINIUM AT A TEMPERATURE ON THE ORDER OF 1000* C. TO 1300* C. TO FORM A HARD SOLID REACTION PRODUCT BEING UNREACTIVE AND ALUMINUM, SAID REACTION PRODUCT BEING UNREACTIVE WITH ALUMINUM AND BEING WETTABLY BY ALUMINIUM.