| CPC C22B 26/12 (2013.01) [B01D 15/1871 (2013.01); B01D 15/1885 (2013.01); B01D 15/203 (2013.01); B01D 15/362 (2013.01); B01J 47/02 (2013.01); B01J 47/14 (2013.01); B01J 49/06 (2017.01); B01J 49/53 (2017.01); B01J 49/60 (2017.01); C22B 3/42 (2013.01); C22B 7/006 (2013.01)] | 8 Claims |
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1. A method for versatile continuous ion-exchange extraction of lithium from natural or technological lithium-containing brine having a predetermined concentration of lithium by using a lithium-selective inorganic sorbent; the method comprises:
a) providing an apparatus comprising: ion-exchange columns comprising a first ion-exchange column, a last ion-exchange column, and intermediate ion-exchange columns between the first ion-exchange column and the last ion-exchange column, the total number of the columns being n, wherein n is a number equal to or exceeding 3, each of the ion-exchange columns having an input unit and an output unit, the ion-exchange columns being sequentially interconnected; an acid desorption tank; an acid dilution reactor; a storage tank; a brine supply manifold for suppling an untreated, lithium-containing brine to the columns; a pipeline for supplying a dilution acidic desorption solution; a flush water supply pipeline; a waste output pipeline; a storage tank draining pipeline; and a plurality of switchable shut-off valves capable of switching interconnections between the ion-exchange columns, the acid desorption tank, the acid dilution reactor, the storage tank, the brine supply manifold, the pipeline for supplying an acidic desorption solution, the flush water supply pipeline, the waste output pipeline, and the storage tank draining pipeline, wherein the switching interconnections being performed in compliance with a technological process used for carrying out the method;
b) electing operation of the apparatus between:
1) a parallel mode of operation at which all ion-exchange columns operate simultaneously and similarly by being filled with the untreated natural or technological brine, subject to a sorption operation for obtaining a processed brine, flushed with flush water for removing a lithium-contain ng residue remained in the ion-exchange columns after the sorption operation, subject to a desorption operation performed by passing therethrough the acidic desorption solution prepared in the acid dilution reactor thus forming a desorption solution, and outputting the desorption solution to the storage tank and then to the storage tank draining pipeline for further processing;
2) a serial mode of operation comprising performing subsequent cycles of sorption-washing-desorption-washing in each column in sequence from the first ion-exchange column to the last ion-exchange column through the intermediate ion-exchange columns with the transfer of a brine processed in each ion-exchange column from the first ion-exchange column to the last ion-exchange column through the intermediate ion-exchange columns, and converting the last ion-exchange column into the first ion-exchange column upon completion of the last one of the subsequent cycles of sorption-washing-desorption-washing by transferring a brine processed in the last ion-exchange column to the first ion-exchange column further comprising sending the flush water after each flushing to the waste output pipeline checking in the serial mode of operation a content of lithium in the acidic desorption solution and switching appropriate shut-off valves of said plurality of switchable shut-off valves for sending the acidic desorption solution to the acid dilution reactor via the acid desorption tank when the content of lithium is still lower a predetermined value at which the desorption solution is used for further processing outside the apparatus.
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