Granular fertilizer from calcium metaphosphate

Claim 1

A PROCESS FOR THE PRODUCTION OF A GRANULAR, NONHYGROSCOPIC, FREE-FLOWING FERTILIZER CONTAINING AN AMMONIUM SALT, CALCIUM METAPHOSPHATE, INCOMPLETELY HYDROLYZED METAPHOSPHATE, AND CALCIUM ORTHOPHOSPHATE WHICH COMPRISES INTRODUCING A SOLID FERTILIZER MATERIAL COMPRISING CALCIUM METAPHOSPHATE INTO A ROTATING DRUM, MAINTAINING A ROLLING BED OF SOLID MATERIAL WITHIN THE DRUM, INTRODUCING A CONCENTRATED ACID SELECTED FROM THE GROUP CONSISTING OF SULFURIC ACID, PHOSPHORIC ACID, AND NITRIC ACID AND MIXTURES THEREOF BENEATH THE SURFACE OF THE ROLLING BED IN THE INITIAL HALF OF THE DRUM, INTRODUCING AN AMMONIATING FLUID BENEATH THE SURFACE OF THE ROLLING BED IN THE FINAL HALF OF THE DRUM IN QUANTITY SUBSTANTIALLY SUFFICIENT TO NEUTRALIZE THE ACID INTRODUCED, MAINTAINING THE TEMPERATURE OF THE MATERIAL WITHIN THE DRUM IN THE RANGE FROM ABOUT 160* TO 215*F., INTRODUCING WATER BENEATH THE SURFACE OF THE ROLLING BED, CONTROLLING THE QUANTITY OF WATER INTRODUCED SO THAT THE TOTAL WATER INTRODUCED LESS THAT EVAPORATED IS NOT MORE THAN ABOUT TWO-THIRDS THAT REQUIRED FOR COMPLETE HYDROLYSIS OF CALCIUM METAPHOSPHATE FED, PASSING THE BED OF MATERIAL THROUGH THE DRUM AT A RATE OF FLOW TO PROVIDE A RETENTION TIME IN THE DRUM OF ABOUT 3 TO 8 MINUTES, AND WITHDRAWING AT LEAST PARTIALLY GRANULATED FERTILIZER FROM THE DRUM.