Phosphogypsum (PG) is the co-product of phosphoric acid manufacture. Most PG is sent to waste at substantial cost. We support a burgeoning trend to utilize PG for a variety of uses in agriculture, construction, cement, and other industries. We coordinate with the international Phosphogypsum Working Group (PGWG) – especially Aleff Group and FIPR, developing technology, identifying markets, and evaluating financial and environmental benefits.
John Wing has done process design for disposal of PG to wet and dry stacks and to ocean. He has visited clients worldwide who already sell PG for a variety of uses, and others who are considering PG utilization.
Fluosilicic Acid Recovery
We have designed several systems to recover fluosilicic acid (FSA) from phosphoric acid evaporators. FSA is used to fluoridate municipal water or to make ALF3 – a chemical used in aluminum manufacture. Our last two projects employed advanced spray-cyclonic scrubbers, rather than older spray towers. These are less expensive, more efficient, and more resistant to fouling.
Brochures describing experience with phosphogypsum and FSA recovery are available upon request at JohnWingPE@verizon.net.
PresentationsJohn Wing has made presentations about PG utilization and recovery of fluosilicic acid (FSA), uranium, and rare earths from phos acid at international conferences, including:
- DAP & Phos Acid Plant Improvements,Arab Fertilizer Assn.,Amman, 2011
- Phosphoric Acid: Valuable Source of By-Products, CRU Phosphates 2013 Conf.
- PG Era: Utilizing Phos. Industry’s Most Abundant Co-Product, AIChE, CW, 2016