STAFF-INDUSTRY COLLABORATIVE REPORT Granulated Triple Superphosphate

Fertilizer Technology, Development of a One-Step Process for Production of Granular Triple Superphosphate

“…Drying at 140°F. to a moisture content of about 3% resulted in a 4 to 6% decrease in conversion. Control of a drying operation to avoid reversion appeared to be difficult.…”

“…This process is costly because extra handling is involved and the granules must be dried. In another process (4), granular triple superphosphate is produced by acidulating phosphate rock with phosphoric acid in a slurry state and then mixing the slurry with dried recycle product in a pugmill.…”

“…Conversion of the phosphate in the rock to a citrate-soluble form was 93% complete after 1 week, 94% after 2 weeks, and 97%. after 4 weeks of curing in a pile at room temperature. The product contained 46.0% available and only 0.8%.…”

Fertilizer Technology, One-Step Continuous Quick-Curing Triple Superphosphate Process Employing Rod Mill Grinding

“…Many processes (3,5,9,72) have been tried for quick-curing of triple superphosphate. None of these processes has been able to eliminate curing time entirely without loss of phosphorus availability.…”