Porous mullite bodies and methods of forming them

• Main Authors: ALLEN SHARON, NILSSON ROBERT T, ZIEBARTH ROBIN, WALLIN STEN A, GALLAGHER TIMOTHY J, PYZIK ALEKSANDER J, SAHA CHANDAN, HAN CHAN, PRUNIER ARTHUR R.JR
• Format: Patent
• Language: English
• Published: 30.08.2007
• Subjects: ARTIFICIAL STONE; BLASTING; CEMENTS; CERAMICS; CHEMISTRY; COMPOSITIONS BASED THEREON; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDINGMATERIALS; CONCRETE; ENGINE PLANTS IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNALCOMBUSTION ENGINES; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES ORENGINES IN GENERAL; HEATING; LIGHTING; LIME, MAGNESIA; MACHINES OR ENGINES IN GENERAL; MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONSONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS; MECHANICAL ENGINEERING; METALLURGY; ORGANIC MACROMOLECULAR COMPOUNDS; PERFORMING OPERATIONS; PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL; REFRACTORIES; SEPARATION; SLAG; STEAM ENGINES; THEIR PREPARATION OR CHEMICAL WORKING-UP; TRANSPORTING; TREATMENT OF NATURAL STONE; WEAPONS

A porous mullite composition is made by forming a mixture of one or more precursor compounds having the elements present in mullite (e.g., clay, alumina, silica) and a property enhancing compound. The property enhancing compound is a compound having an element selected from the group consisting of Mg, Ca, Fe, Na, K, Ce, Pr, Nd, Sm, Eu, Gd, Th, Dy, Ho, Er, Tm, Yb, Lu, B, Y, Sc, La and combination thereof. The mixture is shaped and to form a porous green shape which is heated under an atmosphere having a fluorine containing gas to a temperature sufficient to form a mullite composition comprised substantially of acicular mullite grains that are essentially chemically bound.