Process for recovering ammonia from a raschig synthesis reaction

Claim 1

IN THE RECOVERY OF EXCDSS AMONIA FROM A RASCHIG MIXTURE WHICH IS AT A SUBSTANTIAL SUPERATMOSPHERIC PRESSURE, WHICH HAS BEEN PREPARED BY REACTING AQUEOUS CHLOROAMINE SOLUTION AND A LARGE EXCESS OF AMMONIA AND WHICH CONTAINS HYDRAZINE, SODIUM CHLORIDE, WATER AND EXCESS AMMONIA, THE STEPS OF FRACTIONALLY DISTILLING SAID MIXTURE IN A FIRST STAGE AT A SUBSTANTIAL SUPERATMOSPHERIC PRESSURE TO PROVIDE AN OVERHEAD CONSISTING ESSENTIALLY OF AMMONIA AND A SMALL PROPORTION OF WATER AND A BOTTOMS CONSISTING ESSENTIALLY OF AMMONIA, HYDRAZINE, SODIUM CHLORIDE AND WATER, AND THEREAFTER FRACTIONALLY DISTILLING THE BOTTOMS IN A SECOND STAGE AT SUBSTANTIALLY LOWER PRESSURES THAN IN THE FIRST STAGE TO PROVIDE AN OVERHEAD CONSISTING ESSENTIALLY OF ANHYDROUS AMMONIA AND A BOTTOMS CONSISTING ESSENTIALLY OF HYDRAZINE, SODIUM CHLORIDE AND WATER, THE BOTTOMS TEMPERATURE IN EACH DISTILLATION STAGE NOT EXCEEDING ABOUT 155*C.