Production of ammonium nitrite solutions

Claim 1

IN A PROCESS FOR PRODUCING AMMONIUM NITRITE SOLUTION BY CONTACTING NITROUS GAS CONTAINING AS NITROGEN OXIDE CONSTITUENTS NITRIC OXIDE AND NITROGEN DIOXIDE IN THE MOL RATIO OF AT LEAST 4:1 NITRIC OXIDE:NITROGEN DIOXIDE, SAID NITROUS GAS HAVING NITRIC OXIDE CONCENTRATION OF AT LEAST 2 MOL PERCENT AND INERT GAS CONCENTRATION OF AT LEAST 65 MOL PERCENT, WITH OXYGEN AND AT LEAST ONE BASIS AMMONIUM COMPOUND OF THE GROUP CONSISTING OF THE AMMONIUM CARBONATES AND AMMONIUM SULFITE DISSOLVED IN AQUEOUS BASIC SOLLUTION, THE IMPROVEMENT WHICH COMPRISES: MAINTAINING AT LEAST A PAIR OF COMMUNICATING GASLIQUID SCRUBBING ZONES; RECIRCULATING THROUGH EACH OF SAID ZONES A SEPARATE BODY OF THE AQUEOUS BASIMC SOLUTION; COOLING THE SEPARATE BODY OF SOLUTION IN EACH ZONE TO TEMPERATUREE BETWEEN ABOOUT 40*C. AND ABOUT MINUS 5*C; FEEDING INTO ABSORBING CONTACT WITH THE AQUEOUS SOLUTION IN THE FIRST ZONE AT LEAST PART OF THE INCOMING NITROUS GAS; CONTINUING SAID ABSORBING CONTACT IN SAID FIRST ZONE UNTIL 1/4-3/4 OF THE NITROGEN OXIDE CONTENT OF THE GAS IS REMOVED FROM THE GAS FED THERETO; CONTINUOUSLY PASSING THE INCREMENT IN THE BODY OF SOLUTION IN EACH ZONE EXCEPT THE LAST ONE TO A BODY OF SOLUTION OF A ZONE FOLLOWING AND CONTINUOUSLY PASSING UNABSORBED GAS FROM EACH ZONE EXCEPT THE LAST ONE TO A ZONE FOLLOWING, THEREBY MAINTAINING IN THE BODY OF SOLUTION IN EACH ZONE SUCCESSIVELY LOWER CONCENTRATION OF BASIC AMMONIUM COMPOUND IN CONTACT WITH NITROUS GAS SUCCESSIVELY LESS CONCENTRATED IN SAID NITROGEN OXIDE CONSTITUENTS; WITHDRAWING UNABSORBED GAS FROM THE LAST ZONE; AND WITHDRAWING AS PRODUCT THE INCREMENT IN AMMONIUM NITRITE SOLUTION FROM THE LAST ZONE.