Dap and Phosphoric Acid Plant Improvements

Abstract

A selection of attractive modifications are described, based on successful projects.
DAP innovations include:

• Dual Mole Reactor-Granulator Acid Scrubbing
• BFL Vaporizer/Scrubber - Vaporizes all ammonia with free heat from air leaving the reactor-granulator acid scrubber. This unit provides a 3rd stage of scrubbing – potentially eliminating need for any tail-gas scrubber.
• Product Screen Diverter Systems – easy capacity increase
• Automated Recycle Control - continuously monitors recycle particle size and adjusts process to keep size in mid-range.
• Dual diameter reactor (pre-neutralizer)
• Pipe Reactor
• Cooler Air Chiller
• Tran-Tech Product Cooler

Phosphoric Acid plant projects to consider include:

• Conversion from Dihydrate to Hemi: Makes acid at 42% concentration vs. ~27%
  
  • No need for most evaporation. Usually no rock grinding is needed.
• Conversion to Hemi-Di – similar benefits plus 98.5% recovery & clean gypsum
• Utilize gypsum – many ways to make gypsum an asset rather than liability
• Recover uranium – major investment with high profit potential
• Recover fluosilicic acid – high-purity grade for AlF3 feed
• A variety of profitable uses for phosphogypsum
• Advances in dry gypsum stacking
• Purify phosphoric acid to technical or food grade

Project management and start-up issues are discussed.