Production of urea-ammonium nitrate suspension fertilizer

摘要

Highly concentrated nitrogen suspension fertilizers which have excellent long-term storage and handling properties in both warm and severely cold weather are produced from urea, ammonium nitrate, water, and attapulgite clay and contain urea crystals suspended in a saturated solution containing urea and ammonium nitrate. The compositions must be maintained within a very narrow range to produce satisfactory suspensions. Deviation from this narrow range results in poor quality, unusable products. For prevention of scale formation and production of small crystals, the products are cooled in two or more stages with gelling-type clay added prior to or during crystallization and with air cooling used in the cooling stage(s) involving crystallization.