GRANULATED AMMONIUM NITRATE PRODUCTION PROCESS Russian patent published in 2000 - IPC

FIELD: inorganic fertilizers. SUBSTANCE: process comprises neutralization of nitric acid with gaseous ammonia to form vapor and aqueous ammonium nitrate solution, evaporation of this solution to achieve high-concentration melt and to form gas-vapor mixture, granulation of melt in granulation tower in countercurrent with air-containing cooling agent to form ammonium nitrate granules and hot air-containing current, cooling of ammonium nitrate granules thus obtained in fluidized-bed apparatus involving air- containing cooling agent, mixing of postevaporation gas-vapor mixture with hot postgranulation air-containing current, and purification and cooling of gas-vapor mixture in washing apparatus involving ammonium nitrate solution reflux. Process is distinguished by that purification and washing operations are carried out in washing column with three reflux zones and gas-vapor mixture from first zone is divided into two equal streams, the first one being fed into the second reflux zone and then into melt granulation stage as cooling agent, while the second stream is introduced into the third reflux zone and then into granule cooling stage as cooling agent. EFFECT: enabled reuse of air-containing currents and closed air circuit thereby preventing emissions into atmosphere. 1 dwg