Production of urea-ammonium polyphosphates from urea phosphate

摘要

Crystalline urea phosphate is pyrolyzed in one stage to give molten urea ammonium polyphosphates that contains up to 95 percent of the phosphate as polyphosphate. These are then processed into high-analysis solid or liquid fertilizers. Addition of urea to the process to maintain a urea:biuret ratio of at least 16 prevents precipitation of biuret in the liquid fertilizers.