CO(II) EXCHANGE INTO ZEOLITE-A AND ZEOLITE-X FROM FORMAMIDE SOLUTION DEPENDS UPON WATER-CONTENT

Ion exchange of Co(II) for Na+ was attempted at 23 degrees C for zeoli tes A and X using solvents which ranged in composition from pure water to incompletely dried formamide. The results show that the extent of ion exchange is approximately proportional to the water content for [H 2O] < 1.5 M, apparently extrapolating to zero at zero water content. S mall amounts of water in formamide disproportionately increase the ext ent of ion exchange, and small amounts of formamide in water dispropor tionately hinder ion exchange. No pure organic solvent has yet been fo und which is suitable for ion exchange into zeolites. (C) Elsevier Sci ence Inc. 1996