Process for the production of fertilizer materials

Claim 1

IN A CONTINUOUS PROCESS FOR THE DECOMPOSITION OF POTASSIUM CHLORIDE WITH ACIDS, WHICH PROCESS COMPRISES REMOVING THE EVOLVED GASES CONTAINING CHLORINE AND NITROSYL CHLORIDE, REMOVING THE LIQUID PRODUCT OF THE ACID DECOMPOSITION OF POTASSIUM CHLORIDE FROM THE REACTION, TREATING THE SAME WITH A PHOSPHORIC COMPOUND, AND RECYCLING NITROGEN OXIDES TO THE FIRST STAGE OF THE PROCESS, THE IMPROVEMENT COMPRISING REACTING THE POTASSIUM CHLORIDE WITH A MIXTURE CONSISTING ESSENTIALLY OF NITRIC ACID OF A CONCENTRATION OF FROM ABOUT 40 TO 95% BY WEIGHT AND SULPHURIC ACID OF A CONCENTRATION OF FROM ABOUT 70 TO 98% BY WEIGHT, SAID NITRIC AND SULPHURIC ACIDS BEING PRESENT IN AMOUNTS EXCEEDING THE AMOUNTS THEREOF STOICHIOMETRICALLY REQUIRED FOR REACTION WITH POTASSIUM CHLORIDE BY AT LEAST 10%, AT A TEMPERATURE IN THE RANGE OF ABOUT 80 TO 120* C.; REACTING THE RESULTING EVOLVED GASES CONTAINING CHLORINE AND NITROSYL CHLORIDE WITH CONCENTRATED SULPHURIC ACID; SEPARATING THE RESULTING GASEOUS PRODUCTS COMPRISING CHLORINE AND HYDROGEN CHLORIDE, AND THE RESULTING LIQUID PRODUCT COMPRISING SULPHURIC ACID AND NITROSOSULPHURIC ACID FROM EACH OTHER; ADDING TO THE LATTER PRODUCT A MEMBER SELECTED FROM THE GROUP CONSISTING OF NITRIC ACID AND WATER, THEREBY DECOMPOSING THE NITROSOSULPHURIC ACID THEREIN TO SULPHURIC ACID AND AN OXIDE OF NITROGEN; AND INTRODUCING THE RESULTING LIQUID PRODUCT CONTAINING SULPHURIC ACID AND NITRIC ACID INTO THE ABOVE REACTION WITH POTASSIUM CHLORIDE.