The Power of Rare Earths
Rare Earths: The Elemental Advantage
Rare earths have a distinct chemical advantage over competing phosphate reduction products because of their natural affinity for elemental phosphorus.
The rare earths are a group of naturally occurring elements, represented on the period table as the lanthanides, which are elements 57 through 71. (Yttrium, element 39, is also considered a rare earth element). The two rare earth elements that are the active ingredients in RE300 are cerium and lanthanum, elements 57 and 58. They are the most common of all of the rare earth elements.
In the ground, cerium and lanthanum exist naturally in a mineral complexes, most often in conjunction with phosphorus, to which they are preferentially attracted. This cerium/lanthanum mineral is called rhabdophane: (Ce,La)PO4.
After mining, rhabdophane is processed to separate the cerium and lanthanum into their elemental forms. Neo Performance Materials then further processes cerium and lanthanum into a chloride solution. That comprises our two primary wastewater treatment projects: RE300 and RE100.
When RE300 is introduced into a wastewater stream as a coagulant, it seeks out and forms strong crystalline bonds with phosphorus, forming an insoluble rhabdophane precipitate. This precipitate is relatively heavy and dense; cerium and lanthanum have relatively high molecular weights (138 and 140, respectively). Therefore, the RE300-formed rhabdophane precipitate settles rapidly during clarification.
By comparison, aluminum and iron have lower molecular weights (27 and 55, respectively), and do not form strong molecular bonds with phosphorus. They are not as efficient as RE100 and RE300 in removing phosphorus from wastewater streams.
RE100 and RE300 also provide additional additional benefits, such as increased sludge density and improved water/solids separation and dewatering. You can see the full list of their benefits here.