Abstract: A method of applying a high alumina, low cement refractory castable to the surface of a refractory structure, comprising the steps of:a) preparing an intimately mixed castable for application onto the surface of a refractory structure, the refractory castable including by weight the following components:80% to 86% alumina aggregate,about 6% to 11% thermally reactive calcined alumina,about 4% to 8% calcium aluminate cement;b) conveying the refractory castable under pressure through a delivery hose to a dispensing nozzle for applying the refractory castable; andc) adding calcium chloride to the refractory castable prior to application by the nozzle at a rate wherein the calcium chloride comprises about 0.05% to 0.15% by weight of the refractory castable applied by the dispensing nozzle.

Abstract: A method of applying a refractory castable onto a surface of a refractory structure, comprising the steps of: [a)] preparing a thoroughly mixed wet castable for application onto a surface of a refractory structure; [b)] conveying the wet-mixed refractory castable at a set rate under pressure through a delivery hose having a predetermined cross-sectional area to a dispensing device having an air inlet and a dispensing nozzle; [c)] introducing air under pressure into the dispensing device, wherein the air pressure ranges from about 20 psi to about 80 psi and wherein the air has a velocity of about 177 ft/sec at 20 psi and an air velocity of about 484 ft/sec at 80 psi and wherein the velocity increases by about 5 ft/sec for every unit increase in the pressure.

Abstract: A process for applying a refractory castable onto a surface, comprising the steps of: (a) introducing metered amounts of a clay-free, dry refractory castable into a delivery hose, the dry refractory castable having an alumina content of about 40-95%; (b) conveying the dry refractory to a dispensing assembly under pneumatic pressure; (c) introducing water and a set modifying admixture into the dry refractory prior to dispensing the refractory castable from the dispensing assembly; and (d) spraying the hydraulic refractory castable onto a surface.

Abstract: A method of applying a cement-free refractory castable to the surface of a refractory structure, comprising the steps of:a) preparing an intimately mixed refractory castable having alumina aggregate and a cement-free binder comprised of hydratable alumina;b) conveying the refractory castable under pressure through a delivery hose to a dispensing nozzle for applying the refractory castable; and,c) adding a salt solution to the refractory castable prior to application by the nozzle at a rate wherein the salt solution comprises about 0.2% to 0.9% by weight of the refractory castable applied by the dispensing nozzle.

Abstract: A method of applying a refractory castable material to the surface of a structure comprising the steps of thoroughly mixing a refractory castable material comprised primarily of aggregate and a cementitious binder; conveying the refractory material under pressure through a delivery hose to a dispensing nozzle; and adding hydrated lime to the refractory castable material prior to application by the nozzle.