| abstract |
Process for preparing zeolites of X type having an Si/Al atomic ratio of <=1.5 and having exchangeable cations including lithium, trivalent and/or divalent ions, and optionally sodium, potassium, ammonium and/or hydronium ions, involves distributing starting zeolite in a series of receptacles, percolating a solution of at least one lithium compound through the series, drawing a lithium-containing bleed from first receptacle of the carrousel, and drawing off a final effluent stream from a final receptacle in the series. The effluent stream contains compounds of exchangeable cations from the starting zeolite and traces of the lithium compound(s). After a desired degree of lithium exchange has occurred in the first receptacle, the first receptacle is removed and a fresh solution of at least one lithium compound is introduced into the next receptable in the series and percolated through the series. This step can be performed for each receptacle in the series. |