The Ferralium 255 impeller was one of the first in this new super duplex stainless steel material to be used in ‘wet process’ phosphoric acid production and, at the time of its removal from the plant, had given three years continuous service without any maintenance, handling acid slurries containing approximately 30% P2O5, 30% CaSO4 solids, 2% H2SO4, HF and H2SiF6 at between 60-80°C.
The superiority of Ferralium 255 over the high nickel alloy previously used for this duty had led to its adoption for all slurry pumps in this plant and use of the alloy has now also been extended to evaporator circulation pumps handling acid of 45-55% P2O5 where even longer service life is expected. Such performances are by no means unusual with Ferralium 255 (UNS S32550, Alloy 255, DIN 1.4507, ASTM F61) which is now enjoying many similar successes in other ‘wet process’ plants and is becoming increasingly used in both here and abroad.
For instance, these agitator blade assemblies with stabilisers, fabricated in Ferralium 255, are destined for a phosphoric plant now under construction for a large fertiliser manufacturer in Spain, and will be used in the handling of phosphoric acid slurry.
If you’d like more information regarding Ferralium 255, please get in touch with a member our expert team today.