Ammoniation of superphosphate

Claim 1

A PROCESS FOR AMMONIATING SUPERPHOSPHATE WHICH COMPRISES CONTINUOUSLY INTRODUCING SUPERPHOSPHATE INTO AN UPPER END OF AN INCLINED DRUM; THEREIN MAINTAINING A BED OF ROLLING DISCRETE PARTICLES OF SUPERPHOSPHATE HAVING A DEPTH OF ABOUT ONE FOURTH TO TWO FIFTHS OF THE DIAMETER OF THE DRUM; MAINTAINING THE SURFACE OF THE BED OF ROLLING PARTICLES AT AN INCLINATION OF ABOUT 30* TO 45* TO THE HORIZONTAL DIAMETER OF THE DRUM; PASSING EACH OF THE PARTICLES THROUGH THE BED FROM END TO END OF THE DRUM IN A CONTINUOUS CURVED PATH APPROXIMATING A FLATTENED HELIX OF MANY TURNS, HAVING UPWARD-INCLINED TURNS ADJACENT TO THE INNER SURFACE OF THE DRUM AND DOWNWARD-INCLINED TURNS ADJACENT TO THE UPPER SURFACE OF THE BED; PASSING THE PARTICLES AT LOWER SPEED THROUGH UPWARD TURNS OF THE HELICAL PATH THAN THROUGH DESCENDING TURNS; CONTINUOUSLY INTRODUCING AMMONIATING FLUID BENEATH THE SURFACE OF THE BED IN A BROAD STREAM COUNTERCURRENT TO THE UPWARD MOVEMENT OF SAID PARTICLES IN SUCH PATH, THE BREATH OF SAID STREAM EXTENDING SUBSTANTIALLY GREATER RATE LENGTH OF THE BED; MAINTAINING SUBSTANTIALLY GREATER RATE OF FLOW IN A CENTRAL PART OF THE STREAM; CONTINUOUSLY FLUID THAN IN THE EDGE OF SAID STREAM; CONTINUOUSLY PASSING A CURRENT OF AIR OVER THE SURFACE OF SAID BED; AND WITHDRAWING AMMONIATED PRODUCT FROM THE LOWER END OF THE DRUM.