| CPC C22B 26/12 (2013.01) [B01J 39/04 (2013.01); B01J 39/18 (2013.01); B01J 47/02 (2013.01); B01J 49/53 (2017.01); B01J 49/60 (2017.01); C01D 15/00 (2013.01); C22B 3/42 (2013.01)] | 16 Claims |
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1. A method for lithium-sodium separation, comprising the following steps:
allowing a lithium-sodium separation feed solution, first drip washing solution, desorption solution, second drip washing solution and lithium-sodium separation adsorption barren liquid to pass through a feeding pipe for lithium-sodium separation feed solution, a feeding pipe for first drip washing solution, a feeding pipe for desorption solution, a feeding pipe for second drip washing solution, a feeding pipe for adsorption barren liquid for pushing back desorption solution respectively, wherein the feeding pipes are located above and below a rotary disc of a multi-way switching valve system, then pass through openings and channels within the multi-way switching valve system to respectively enter corresponding resin columns, and finally discharge from a discharging pipe for adsorption barren liquid, a discharging pipe for first drip washing solution, a discharging pipe for qualified solution, a discharging pipe for second drip washing solution, a discharging pipe for adsorption barren liquid for pushing back desorption solution, thereby completing the whole process, wherein the resin columns are connected in series or in parallel via the channels in the multi-way switching valve system; and
wherein the whole process comprises the following steps:
(1) in an adsorption zone, carrying out: feeding the lithium-sodium separation feed solution from a tank for lithium-sodium separation feed solution into a resin column N1 through the feeding pipe for lithium-sodium separation feed solution to perform adsorption of lithium ions onto resin, producing a lithium-sodium separation barren liquid after the adsorption of lithium ions, and discharging the lithium-sodium separation barren liquid into a tank for barren liquid through the discharging pipe for adsorption barren liquid;
(2) in a first washing zone, carrying out the following after the resin is saturated: feeding the first drip washing solution from a tank for the first drip washing solution into a resin column N2 through the feeding pipe for first drip washing solution to push back the lithium-sodium separation feed liquid in which lithium ions are not adsorbed to the tank for lithium-sodium separation feed liquid to wait for the next adsorption;
(3) in a desorption zone, carrying out the following after the completion of first washing: feeding a desorption solution from a tank for desorption solution into a resin column N3 through the feeding pipe for desorption solution to desorb lithium ions adsorbed on the resin, and discharging the desorbed lithium ion-rich desorption liquid into a tank for qualified desorption liquid through the discharging pipe for qualified solution;
(4) in a second washing zone, carrying out the following after the desorption is completed: feeding the second drip washing solution from a tank for second drip washing solution into a resin column N4 through the feeding pipe for second drip washing solution to push back the unused desorption liquid in the resin column to the tank for desorption liquid to wait for use in the next desorption step;
(5) in a zone for pushing back water by adsorption barren liquid, carrying out the following after the completion of second washing: feeding the lithium-sodium separation adsorption barren liquid from the feeding pipe for adsorption barren liquid into a resin column N5 to replace the second drip washing solution in the resin column and loose the resin, and recycling the replaced second drip washing solution to a tank for second drip washing solution through the discharging pipe for second drip washing solution to wait for use in the next second washing step; and
(6) setting a rotation time of the multi-way switching valve to realize shift of columns according to the process requirements.
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