nfcl, mangalore dap/npk plant feasibility study - Environmental ...

2ANNEXURE-IVSulphuric acid is used for pH and N/P control and it can be fed toPreneutralizer, to Granulator, to Granulator Pre-scrubber Tank, to the Scrubbertank and to the Tail Gas Scrubber.MOP, Urea, Filler and spillages (or off-spec product) is fed from their storagebuilding to the plant building by common conveyors. Once in the plant there isa common raw material Rotary Diverter, to feed the different solid raw materialto their correspondent bin. The quantity of raw materials added to thegranulation loop is controlled by the variable speed electronic feeders for Urea,Potash, Filler and Off-spec product respectivelySlurry preparation and GranulationDAP and NPKs without Urea are produced by Pipe Reactor(s), where 100% ofthe total ammonium phosphate / sulphate slurries will be generated. For DAPproduction two Pipe Reactors will be used simultaneously. For NPK productionone or two PRs will be used depending on the grade.A molar ratio N/P = 1.4-1.5 is reached at 135-145°C in Pipe Reactor for DAPproduction, as results of neutralizing a phosphoric acid of about 42-44% P2O5(including some sulphuric acid) with liquid ammonia.A molar ratio N/P = 1.4-1.5 is reached at 130-140°C in Pipe Reactor for NPKproduction, as results of neutralizing a phosphoric acid of about 40-42% P2O5(including some sulphuric acid) and liquid ammonia.NPK/NP with high content in Urea is produced using Preneutralizer Reactor,where 100% of the total ammonium phosphate / sulphate slurries will beprepared. In case of using mixed process, the slurry will be produced byPreneutralizer and Pipe Reactors.