Manufacture of metal nitrates

Claim 1

A PROCESS FOR THE MANUFACTURE OF A METAL NITRATE BY REACTION OF NITRIC ACID ON THE METAL GIVING RISE TO THE EVOLUTION OF THE HIGHER OXIDES OF NITROGEN, WHICH PROCESS COMPRISES IMMERSING A COLUMN OF THE SELECTED METAL AT LEAST PARTLY IN A SOLUTION OF THE NITRATE OF SAID METAL MAINTAINED AT A PREDETERMINED HEIGHT SURROUNDING AND DISPLACEABLE FROM SAID COLUMN, CONTINUOUSLY BRINGING A FILM OF NITRIC ACID AT A REGULATED RATE INTO CONTACT WITH THE UPPER PORTION OF SAID METAL COLUMN TO CAUSE REACTION OF SAID ACID WITH SAID METAL WITH CONTINUOUS FORMATION OF NITRATE SOLUTION AND CONSTANT EVOLUTION OF A REGULATED AMOUNT OF NITROGEN OXIDE FUMES, SIMULTANEOUSLY CONTINUOUSLY INTRODUCING TO SAID REACTION ZONE OXYGEN GAS AT A RATE SUFFICIENT TO REPLACE THE OXYGEN USED IN CONVERTING THE EVOLVED NITROGEN OXIDES DIRECTLY TO NITRIC ACID AND TO MAINTAIN THE PRESSURE IN THE REACTION ZONE SUBSTANTIALLY CONSTANT, CAUSING SAID RECONVERTED NITRIC ACID TO REACT WITH SAID METAL TO INCREASE THE CONCENTRATION OF THE NITRATE SOLUTION, AND CONTINUOUSLY REMOVING THE NITRATE SOLUTION AS ADDITIONAL NITRATE SOLUTION IS FORMED.