Procedimiento para la separacion y recuperacion de una sal de metal alcalino purificada que comprende tratamiento de eliminacion de una sustancia inhibidora de la purificacion de una solucion acuosa de sal de metal alcalino con membrana de separacion.

摘要

The present invention relates to a method for separating and recovering a purified alkali metal salt from an aqueous alkali metal salt solution, the method including a treatment step of removing a purification-inhibiting substance from an aqueous alkali metal salt solution with a separation membrane having a glucose removal ratio and an isopropyl alcohol removal ratio simultaneously satisfying the following expressions (I) and (II) when each of a 1000 ppm aqueous glucose solution having a temperature of 25° C. and pH of 6.5 and a 1000 ppm aqueous isopropyl alcohol solution having a temperature of 25° C. and pH of 6.5 is permeated through the separation membrane at an operating pressure of 0.75 MPa: Glucose removal ratio>=90% . . . (I), Glucose removal ratio-Isopropyl alcohol removal ratio>=30% . . . (II).