Many wet process phosphoric acid plants use Filtration Aid to improve gypsum slurry filtration and hence increase production rates and recovery. Filtration Aid are based on the principle of producing larger and more homogeneous particles or gypsum crystals to allow for faster drainage. The size and shape of gypsum crystals directly impact filtration rates, which in turn, influence production rates.

OAN provides polymeric filtration aids specifically designed to coalesce small gypsum crystals into much larger particles creating significantly larger void spaces in the filter cake. The larger void spaces allow for faster liquid drainage time on phosphoric acid filters.

OAN filtration aid can be formulated to improve any phosphoric acid plant production rate by adjusting molecular weight and/or charge to meet the particular operating conditions of each individual operation as well as the unique characteristics of the particular phosphoric acid/gypsum slurry being delivered from the reactors to the filters. Therefore, Filtration Aid selection and performance are plant-specific. OAN filtration aid have shown the ability to improve filtration rates and improve filtration capacity.