Process for distilling cuprammonium rayon used spinning liquors

Claim 1

THE METHOD OF RECOVERING AMMONIA FROM CUPRAMMONIUM RAYON USED SPINNING LIQUOR CONTAINING LESS THAN 0.3% BY WEIGHT AMMONIA AND CONTAINING MORE THAN 99% BY WEIGHT WATER WHICH COMPRISES: ABSORBING AMMONIABEARING VAPORS FROM A FIRST FRACTIONATING COLUMN IN FEED LIQUID, FEEDING A PORTION OF THE FEED LIQUID IN WHICH SAID VAPORS HAVE BEEN ABSORBED TO THE TOP OF THE FIRST FRACTIONATING COLUMN, FEEDING ANOTHER PORTION OF THE FEED LIQUID IN WHICH SAID VAPORS HAVE BEEN ABSORBED TO A SECOND FRACTIONATING COLUMN MAINTAINED AT HIGHER PRESSURES THAN SAID FIRST FRACTIONATING COLUMN, RECOVERING CONCENTRATED AMMONIA FROM THE TOP OF THE SECOND FRACTIONATING COLUMN, FEEDING STEAM INTO THE BOTTOM OF THE SECOND FRACTIONATING COLUMN, FEEDING A LIQUID RESIDUE FROM THE BOTTOM OF THE SECOND FRACTIONATING COLUMN TO THE BOTTOM OF THE FIRST FRACTIONATING COLUMN TO SUPPLY HEAT TO THE FIRST FRACTIONATING COLUMN, PASSING VAPORS FROM THE TOP OF THE FIRST FRACTIONATING COLUMN TO SAID ABSORBING STEP AND DISCARDING FROM THE FIRST FRACTIONATING COLUMN LIQUID SUBSTANTIALLY FREED OF VOLATILE AMMONIA.