| abstract |
A process for impregnating zeolite with a substance such as potassium hydroxide (KOH), and a product of such process. The process preferably includes the steps of dehydrating zeolite crystals, then immersing the dehydrated zeolite crystals in (or spraying the dehydrated crystals with) aqueous KOH and thoroughly mixing the resulting slurry, and finally air drying the mixed slurry to produce KOH--impregnated zeolite crystals. The zeolite crystals (after they are dried) are uniformly impregnated with a concentration of KOH in the range from about 5% to about 15% of the total product weight. In other embodiments, the inventive method includes the step of impregnating zeolite crystals with metal sulfates or soluble salts (such as Fe2S04, FeCl3, CuSO4, CuCl2, ZnSO4, ZnCl2, CoSO4, CoCl, MnSO4, MnCl, sodium selenate, or MgSO4), or other substances such as amino acids (e.g., methionine or lysine), urea, free amines, or vitamins (such as A, D, E, K, Biotin, Choline, Niacin, Riboflavin, and Pantothenic acid). In each embodiment, the presence of a quaternary ammonium cation coating on the impregnated zeolite allows regulated time release control of the impregnating substance, and thus permits a controlled release diffusion (or absorption) rate in air filtration, animal feed, and other applications. The characteristics of the QAC coating on the impregnated zeolite can be varied to control the reaction rate of the impregnating substance. |