Phosphoric Acid Defluorination Plant
Fedmis, RSA

KEMWorks supplied a basic engineering package to Fedmis to remove fluorine from 150,000 tpy of 50% P2O5 phosphoric acid.  The fluorine is removed by air stripping the heated phosphoric acid in a continuous process.  Silica, in the form of diatomaceous earth is added in the process to promote defluorination.  The design fluorine concentration of the purified acid product is 500 ppm.

The continuous air stripping process features recycled stripping air to maximize energy efficiency and minimize fluorine emissions.  This process consumes far less energy than conventional steam stripping or evaporation processes.

Project Highlights:

• Basic engineering package completed in November 2000.
• Modular layout with minimum plot area.
• Plant installation and start-up scheduled for 2001.