The invention relates to a process and a device for extracting battery grade
lithium from brine. The process comprises the following steps: adding an adsorbent into the brine to adsorb
lithium ions in the brine, intercepting the adsorbent by using a
ceramic membrane filter, performing plate-frame pressure
filtration on the
ceramic membrane concentrated solution to obtain an adsorbent
filter cake, washing and desorbing the adsorbent
filter cake so as to obtain a
desorption solution; removing
magnesium in the
desorption solution through a
nanofiltration membrane
system, entering the
nanofiltration membrane permeate into an
ion exchange resin
tower for performing deep
magnesium removal, concentrating through a
reverse osmosis membrane, performing deep concentration in a DTRO membrane or
electrodialysis equipment, evaporating the concentrated solution, adding BaCl2, Na2CO3 and NaOH into the solution, stirring, filtering in a
ceramic membrane filter, performing plate-frame pressure
filtration on the
ceramic membrane filtrate, adding Na2CO3 into the
clear liquid, preparing Li2CO3, washing Li2CO3 through a
ceramic membrane, centrifuging, and
drying, thereby obtaining the finished battery grade Li2CO3 product.