A composition of matter and method of forming a radiation shielding member at ambient temperatures in which the composition of matter includes a cold-fired chemically bonded oxide-phosphate ceramic cement matrix; with one or more suitably prepared and distributed radiation shielding materials dispersed in the cold-fired chemically bonded oxide-phosphate ceramic cement matrix.

A gasket material for high pressure high temperature presses, comprising: a proportion of a clay mineral a proportion of a hard material for increasing the viscosity of the clay mineral a proportion of a binder selected from the group of borate binders, phosphate binders, and mixtures thereof.

A castable refractory composition comprises: a cement-free refractory particulate composition; and a sol binder; wherein the castable refractory composition comprises a metaphosphate-providing component and/or an orthophosphate-providing component.

A method of making a proppant may include providing a feed material, extruding the feed material through a nozzle of a rotating body to form a green body, the nozzle being positioned between a plurality of projections and passing from an exterior of the rotating body to a core of the rotating body, and sintering the green body to form the proppant. The method may include drying the green body prior to the sintering. The extruding may be performed using a gear pelletizer. An feed material composition may include a ceramic precursor, a binder, a lubricant, and water. The ceramic precursor may include bauxite. The ceramic precursor may include bauxite and calcium carbonate. The binder may include sodium lignosulfonate. The lubricant may include aluminum stearate, zinc stearate, or oleic acid. The sintered proppants may have a density greater than or equal to about 3.7 g/cm.sup.3.

A refractory composition and processes for manufacture are provided where the compositions possess improved refractory alkali resistance and superior handling properties. Compositions and processes for their manufacture may include a plurality of ceramic particles and a binder sintered to the particles wherein the binder includes crystalline aluminum orthophosphate distributed as the result of an in situ reaction of aluminum metaphosphate with alumina. Kits provided according to the invention provide materials for use in manufacture of a composition where the kit includes aluminum metaphosphate and a nonfacile additive.

The disclosure concerns printable refractory compositions, more particularly ceramic-based pastes for 3D printing of molds for additive metal casting. In particular, the present disclosure concerns composition for forming mold regions having controlled thermal conductivity and dissipation and controlled release of gaseous products therefrom during heating to mitigate mechanical failure risks in an additive casting process of metal objects.

The present disclosure concerns printable refractory compositions, more particularly ceramic-based pastes for three-dimensional printing of molds for additive metal casting, that are based on inorganic binders having several, temperature dependent polymerization states, to permit improved adhesion between stacked mold regions in an additive printing process utilizing compositions of the present disclosure.