Method of removing monovalent base ions from sulfite pulping liquors

Claim 1

AN ION EXCHANGE METHOD OF TREATING THE WASTE LIGNOSULFONATE LIQUOR RESULTING FROM MONOVALENT SULFITE PULPING OF WOOD FOR SELECTIVELY SEPARATING SAID MONOVALENT CATIONS FROM MULTIVALENT CATIONS CONTAINED IN THE SAME COMPRISING THE STEPS OF PASSING WASTE LIGNOSULFONATE LIQUOR THROUGH A FIRST ION EXCHANGE RESIN INITIALLY SUBSTANTIALLY SATURATED WITH HYDROGEN IONS TO EFFECT INTERCHANGE OF CATIONS IN THE WASTE LIQUOR FOR SAID HYDROGEN IONS ON THE FIRST RESIN AND UNTIL MONOVALENT CATIONS COMMENCE TO LEAK FROM THE FIRST RESIN WITH THE EFFULENT THEREFROM; THEN DIRECTING THE EFFLUENT FROM SAID FIRST RESIN AND CONTAINING SAID MONOVALENT CATIONS THEREIN THROUGH A SECOND ION EXCHANGE RESIN INITIALLY SUBSTANTIALLY SATURATED WITH HYDROGEN IONS TO EFFECT PREFERENTIAL INTERCHANGE OF SAID MONOVALENT CATIONS IN THE EFFLUENT FROM THE FIRST RESIN FOR SAID HYDROGEN IONS ON THE SECOND RESIN AND UNTIL A SIGNIFICANT PROPORTION OF MULTIVALENT CATIONS BEGIN TO LEAK WITH SAID EFFLUENT FROM THE FIRST RESIN; COLLECTING THE LIGINSULFONIC ACID EFFLUENT EMERGING FROM SAID SECOND RESIN UNTIL A SIGNIFICANT AMOUNT OF SAID MONOVALENT CATIONS BEGIN TO LEAK THEREFROM WITH SAID LIGNINSULFONIC ACID EFFLUENT; PASSING THE LIGNINSULFONIC ACID EFFLUENT COLLECTED FROM SAID SECOND RESIN THROUGH SAID FIRST RESIN UPON CESSATION OF PASSAGE OF SAID WASTE LIGNINSULFONATE LIQUOR THROUGH THE SAME TO EFFECT INTERCHANGE OF HYDROGEN IONS IN SAID LIGNINSULFONIC ACID EFFLUENT FOR MONOVALENT AND MULTIVALENT CATIONS ON THE FIRST RESIN AND THEREBY REGENERATING THE LATTER; AND PASSING A SOLUTION CONTAINING SULFUROUS ACID THROUGH THE SECOND RESIN UPON CESSATION OF PASSAGE OF SAID EFFLUENT FROM THE FIRST RESIN THROUGH THE SAME TO EFFECT INTERCHANGE OF HYDROGEN IONS IN THE SULFUROUS ACID FOR SAID MONOVALENT CATIONS ON THE SECOND RESIN AND THEREBY SIMULTANEOUSLY REGENERATING THE LATTER AND PRODUCING A FRESH MONOVALENT SULFITE COOKING LIQUOR.