Selective Extraction of Rare Earth Elements from Phosphoric Acid by Ion Exchange Resins

Xavier Hérès,Abla Ouaattou,Frederic Cuer,Hamid Mazouz,Vincent Blet,Patricia Di Natale,Driss Dhiba

doi:10.3390/met8090682

Xavier Hérès, Abla Ouaattou + Show 5 more

Open Access

https://doi.org/10.3390/met8090682

Copy DOI

Abstract

Rare earth elements (REE) are present at low concentrations (hundreds of ppm) in phosphoric acid solutions produced by the leaching of phosphate ores by sulfuric acid. The strongly acidic and complexing nature of this medium, as well as the presence of metallic impurities (including iron and uranium), require the development of a particularly cost effective process for the selective recovery of REE. Compared to the classical but costly solvent extraction, liquid-solid extraction using commercial chelating ion exchange resins could be an interesting alternative. Among the different resins tested in this paper (Tulsion CH-93, Purolite S940, Amberlite IRC-747, Lewatit TP-260, Lewatit VP OC 1026, Monophos, Diphonix,) the aminophosphonic IRC-747, and aminomethylphosphonic TP-260 are the most promising. Both of them present similar performances in terms of maximum sorption capacity estimated to be 1.8 meq/g dry resin and in adsorption kinetics, which appears to be best explained by a moving boundary model controlled by particle diffusion.

Highlights

As part of the framework agreement of R&D collaboration between OCP SA and CEA, a study was conducted to evaluate the interest of the recovery of rare earth elements (REE) as by-product from the production of phosphoric acid from phosphate rocks
This paper aims at comparing promising commercial resins in view of the industrially viable valorization of REE contained in the highly concentrated phosphoric acid produced by OCP
In order to estimate the extraction efficiency of REE by resins, experiments were carried out following the protocol reported in Section 3.3 with 100 mg of resins contacted by 10 mL of REH or REOCP solution

Summary

Introduction

As part of the framework agreement of R&D collaboration between OCP SA and CEA, a study was conducted to evaluate the interest of the recovery of rare earth elements (REE) as by-product from the production of phosphoric acid from phosphate rocks. The leaching of the phosphorite ore with concentrated sulfuric acid (98 vol.%) leads to phosphoric acid solutions with a concentration ranging from 4 to 5 mol/L, whose temperature can range from 60 ◦ C to 70 ◦ C, after phosphogypsum filtration. These filtered solutions contain rare earth elements (REE) (hundreds of ppm) that can be recovered if the economic balance is positive. Solid supports are generally heat resistant [2,3] This characteristic is very important because of relatively high operating temperatures of phosphoric acid solutions (40–50 ◦ C after storage)

Objectives

Methods

Results

Conclusion