Effects of Dissolution Conditions on the Recovery of Neodymium Phosphate from Waste Magnets

Neodymium-iron-boron alloy(Nd2Fe14B)is used in the manufacture of magnets.Neodymium is one of the rare earth elements and is therefore valuable.Recovery,reuse,and recycling of rare earth elements is necessary to protect this rare earth resource.Recently,a new method for recovering neodymium phosphate from iron-neodymium mixture solutions using a two-step precipitation method has been reported,avoiding the difficulties reported with previous methods.In this method,iron compounds were removed in Step I and neodymium phosphate was precipitated in Step II.This novel phosphate process was proposed because rare earth phosphate is the main component of rare earth ores.In this study,we dissolved actual waste magnets in various acids to obtain neodymium phosphate by this two-step precipitation process.The resulting precipitates were evaluated by XRD(X-ray diffraction),infrared spectroscopy,color hue,UV-visible reflectance spectra,Fe/Nd ratio,and recovery of neodymium and iron.The results showed that neodymium phosphate was selectively obtained by using nitric acid and hydrochloric acid.In particular,samples prepared with nitric acid showed no reddening due to iron compounds.

Recovery of rare earths from spent FCC catalysts by solvent extraction using saponified 2-ethylhexyl phosphoric acid-2-ethylhexyl ester(EHEHPA)

A process to recover rare earth（RE） metals from spent fluid catalytic cracking（FCC） catalysts by solvent extraction was studied, using saponified 2-ethylhexyl phosphoric acid-2-ethylhexyl ester（EHEHPA or P507）. The recovery process involved three steps：（1） leaching REs（mainly lanthanum and cerium）;（2） solvent extraction by applying saponified P507-kerosene system;（3） stripping. Experiments to assure optimal operating conditions were conducted. Results indicated that RE metals could be recovered effectively from spent catalyst with saponified P507-kerosene-HCl system. At room temperature of 25 oC, 10 g spent catalyst with 110 m L of HCl（1 mol/L） could achieve a leaching efficiency of 85%. For extraction, initial pH value of 3.17, organic/aqueous ratio（O/A ratio） of 2：1 with an extractants＇ saponification rate of 20% could obtain 100% efficiency. In the stripping process, 1 mol/L HCl with O/A ratio of 1：1 led to a stripping efficiency of 96%. In the present study, RE metals from spent FCC catalysts were effectively recovered, which avoided wasting a large amount of RE resources. It provides a theoretical support for commercial recycling of RE resources.

Iron recovery and rare earths enrichment from Bayan Obo tailings using Coal-Ca(OH)2-NaOH roasting followed by magnetic separation

The recovery of iron and enrichment of rare earths from Bayan Obo railings were investigated using Coal Ca（OH） 2 NaOH roasting followed by magnetic separation. The influences of roasting temperature, roasting time, coal content, milling time, Ca（OH）2 dosage and NaOH dosage on the iron and rare earths recovery were explored. The results showed that the magnetic concentrate containing 70.01 wt. % Fe with the iron recovery of 94.34G and the tailings of magnetic separation containing 11.46 wt. % rare earth oxides （REO） with the REO recovery of 98. 19% were obtained under the optimum conditions （i. e. , roasting temperature of 650℃, roasting time of 60 min, coal content of 2.0%, milling time of 5 min, and NaOH dosage of 2.0%）. The Ca（OH）2 dosage had no effect on the separation of iron and rare earths. According to the mineralogical and morphologic analysis, the iron and rare earths of Bayan Obo tailings could be utilized in subsequent ironmaking process and hydrometallurgy process.

Rare Earth Industry is Expected to Embrace an Opportunity of Recovery

In the recent several months,the Ministry of Land and Resources and the MIIT one after another unveiled industry supporting policies,rare earth industry is included into the national guidance restructuring plan,a series of favorable factors including the setup of six major rare earth industry groups,and