Chemically impregnated zeolite and method for chemically impregnating and coating zeolite

Abstract

A process for impregnating zeolite with permanganate, such as potassium permanganate, and a product of such process. The process preferably includes the steps of dehydrating zeolite crystals to have about 5% moisture content, mixing the dehydrated zeolite crystals with solid permanganate (preferably potassium permanganate crystals), immersing the solid mixture in, or spraying the solid mixture with, water at about 190.degree. F. and mixing the resulting slurry, and then drying the mixed slurry to produce permanganate-impregnated zeolite crystals having about 15% moisture content. In other preferred embodiments, the inventive method includes the steps of impregnating zeolite with a quaternary ammonium cation (QAC) and then coating the impregnated zeolite with permanganate, or impregnating zeolite with permanganate and then coating the impregnated zeolite with a QAC. Either coating acts as a protective agent for the impregnating substance in each zeolite crystal's interior, and allows regulated time release control of the impregnating substance, thus permitting a controlled diffusion (or absorption) rate in applications in which the coated, impregnated zeolite is employed to absorb contaminants from air or water. Combinations of coated and uncoated zeolite crystals can be chosen to match specific environmental circumstances calculable by analysis of the air or water to be treated. Mixtures of coated and uncoated QAC-impregnated zeolite can be used to react with organics such as benzene, toluene, and xylene, and mixtures of coated and uncoated permanganate-impregnated zeolite can be used to react with hydrogen sulfide, acetone, ethylene glycols, formaldehyde, and other contaminants.

Dependencies are inferred from the claim text.