Pellets of a polycrystalline hydrated alumina, especially Gibbsite, are infused with LiOH to obtain loadings up to 0.33 mol fraction of LiOH in the LiOH/Al(OH).sub.3. The so-prepared material is useful for mixing with a LiX-containing brine solution, producing an interaction of the LiOH infused in the alumina pellets with the X ion (where X represents an acid salt moiety, especially halide) of the LiX-containing brine.
The LiX interaction product is efficiently removed from the alumina pellets by water washing, leaving rejuvenated LiOH which can be used in yet another cycling of LiX formation/water removal. A plurality of loading and unloading cycles are achieved, yielding an appreciable amount of the lithium values derived from the brine.
FIELD OF THE INVENTION:
BACKGROUND OF THE INVENTION:
Over the years, it has been found that ion exchange resin compositions were often fouled by substances in the brine, such as hydrocarbon contaminants, that rendered the ion exchange resin incapable of rejuvenation requiring re-manufacture of resin.
We have now, unexpectedly, found it preferable to infuse LiOH into the polycrystalline hydrated alumina pellets, herein referred to as Al(OH).sub.3, by reacting it, in the presence of water, with LiOH in the absence of NaCl or other salt. We find that infusion of LiOH into Al(OH).sub.3 pellets proceeds with maintenance of pellet integrity up to and beyond 0.2 mol fraction, and up to 0.33 mol fraction of LiOH in the so-formed LiOH/Al(OH).sub.3. Furthermore, we find that having initially prepared the intercalation in the absence of NaCl or other salt, the pellets can then be converted to the LiCl form with aqueous HCl and used for the specific recovery of LiCl from brine without pellet breakage.
Our prior work with intercalating LiCl directly into the crystals to form LiCl/Al(OH).sub.3 was limited to amounts of up to about 0.2 mol fraction of LiCl in order to avoid breaking up the pellets.
Also, we have now determined that these so-altered polycrystalline alumina pellets containing more than 0.2 mol fraction, up to 0.33 mol fraction, of LiCl in the LiCl/Al(OH).sub.3 produced in the presently described method, offer significant improvements in costs and efficiency for recovering LiCl from brine compared to the material identified hereinabove as being of relevance in "Structure And Operation of Dow's New Lithium-Selective Ion-Exchange Resin."
SUMMARY OF THE INVENTION:
The composition comprises pellets, each of said pellets consisting essentially of an integral mass of polycrystalline hydrated alumina pellets morphologically altered by the infusion therein of LiOH (lithium hydroxide) which creates active lithium-specific sites within the crystal layers of the alumina, essentially without decrepitation of the layered structure.
The composition is prepared by adding an aqueous LiOH solution to a polycrystalline hydrated alumina (especially Gibbsite) in an amount to provide up to 0.33 mol fraction of LiOH in the polycrystalline LiOH/Al(OH).sub.3.
The so-prepared infused alumina pellets are used in the process of removing lithium values from brine by contacting it with a solution of LiX (where X is nitrate, sulfate, bicarbonate, halide, or other acid salt moiety, especially chlorine) to convert the LiOH to LiX.
The resulting LiX/Al(OH).sub.3, having a mol fraction of LiX of up to 0.33, especially from above about 0.2 and up to 0.33, is a beneficial improvement in comparison with the previously attained loadings of up to about 0.2 mol fraction of LiX disclosed in our above-identified related application.
Date of Patent:
FMC Corporation (Philadelphia, PA)
Patent File Date:
Feb 13, 1995
Country of Publication:
Current U.S. Classification:
C01D 1500; B01J 2000; C09K 300;