公开(公告)号：US20190263668A1

公开(公告)日：2019-08-29

申请号：US16320285

申请日：2017-07-27

申请人： OCP SA

发明人： Khaoula KHALESS ,  Driss DHIBA

IPC分类号： C01D5/16 ,  C01D5/18

摘要： The present invention relates to a process for producing sodium sulphate from phosphogypsum, comprising: a step (101) of lixiviation of phosphogypsum by means of a basic solution so as to obtain a sodium sulphate solution (S) containing metal impurities, said basic solution comprising a chelating agent suitable for forming complexes with at least one part of said metal impurities, at least one first step (103, 104) of filtration of the sodium sulphate solution by a nanofiltration membrane (NF1, NF2), so as to form a concentrate (C1, C2) containing said complexes and a permeate (P1, P2), a step (105) of evaporation of the permeate (P1, P2) so as to form anhydrous sodium sulphate.