US 2023/0340639 A1Published application

Recovery of rare earth elements from acidic solutions

AssigneeThe Penn State Research Foundation

InventorsBehzad VAZIRI HASSAS, Mohammad REZAEE, Sarma V. PISUPATI

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Abstract

Disclosed herein are methods for the recovery of one or more rare earth elements (REEs). More specifically, disclosed herein is a method comprising n stages, wherein each stage comprises treating a sample comprising one or more REEs with a reagent to form a carbonate, hydroxycarbonate, bicarbonate of one or more rare earth elements. The sample’s pH is adjusted, and the sample is aged to form solid and liquid fractions, where the solid fraction comprises a precipitated salt of the REEs. The method is repeated an n number of times to maximize the recovery % of REEs. This abstract is intended as a scanning tool for the purpose of searching in the particular art and is not intended to be limiting of the present disclosure.

A method comprising n stages, wherein the method comprises:

a first of the n stages comprising:
a) treating a first solution having a first predetermined pH and comprising a first quantity of one or more rare earth elements (REEs) with a reagent under conditions effective to form a salt of one or more rare earth elements, wherein the salt comprises at least one of a carbonate, hydroxycarbonate, bicarbonate, phosphate salt, dihydrogen phosphate salt, hydrogen phosphate salt, or any combinations thereof of the one or more rare earth elements for a first predetermined period of time;
wherein the one or more rare earth elements present in the first solution at the first stage comprises at least one or more of light rare earth elements (LREEs), at least one or more of heavy rare earth elements (HREEs), or a combination thereof;
b) adjusting the first predetermined pH of the first solution to reach a second predetermined pH, wherein the second predetermined pH is higher than the first predetermined pH;
c) aging the first solution for a second predetermined period of time at conditions effective to form a first liquid fraction and a first solid fraction, wherein the first solid fraction comprises at least one of the one or more rare earth element salts;
d) separating the first solid fraction from the first liquid fraction;
and repeating steps a)-d) for n times, wherein:
a first solution in step a) of each subsequent stage is substantially similar to a first liquid fraction formed in step d) of each preceding stage;
wherein a first predetermined pH at step a) of each subsequent stage is higher than a first predetermined pH at step a) of each preceding stage;
wherein a second predetermined pH in step b) of each subsequent stage is higher than the first predetermined pH at step a) of the same stage,
wherein n is at least 2 stages, and wherein the reagent comprises a carbon dioxide gas, a carbonate salt, bicarbonate salt, phosphate salt, dihydrogen phosphate salt, hydrogen phosphate salt, or a combination thereof.

8 more elements

Abstract

Claims41