More information
Description
The demand for rare earth elements (REEs) grows rapidly in recent years due to their unique properties and many strategic industrial applications. The MOHMARER project concerns the creation of new REE selective, hybrid magnetic membranes and sorbents for the REEs separation from extracts coming from coal fly ash leaching process. The main objective of MOHMARER project is the design and synthesis of modern REE selective, hybrid magnetic membranes and sorbents with high stability. A fully innovative approach in this project will be the design and synthesis of novel hybrid REE selective sorbents based on modified magnetic Fe@MWCNTs, closed in silica shell and functionalized with ILs, IIPs and AEP (with increased REE affinity, high adsorption capacity and easy elution for REE(III)). The next innovative approach will the design and synthesis of new resistant REEs selective polymer and hybrid magnetic membranes based on ion imprinted polymers and modified magnetic Fe@MWCNTs with high selectivity, stability, membrane capacity and REE recovery. In view of their potential usage in a future, the next goal will be carrying out the analysis of REE transport through polymer and hybrid membranes and REE recovery from obtained sorbents using the synthetic ion mixture (the same composition, like in leachates). To take a full description and evaluation of the newly designed hybrid magnetic membranes and sorbents, we intend to examine the chemical, mechanical, thermal, rheological and physical properties by means of a variety of techniques and to determine their influence on transport, adsorption and strength properties. To model the REE ions transport through membranes and REE ions sorption kinetics on analysed sorbents will be created computer applications. Finally, the last objective will be the selection of the most optimal composition of particular hybrid sorbents and membranes, by usage of created computer applications
Summary of project results
In recent years, there has been a rapid increase in demand for rare earth elements (REEs), due to their unique properties and many strategic industrial applications. The MOHMARER project was concerned with the development of novel hybrid magnetic membranes and sorbents for the separation of REEs from extracts derived from coal fly ash leaching processes.
During the project, three types of REE selective IIPs and various types of REE selective sorbents based on modified Fe@MWCNTs were developed and synthesized. To improve their REE affinity, capacity to adsorb REE ions and further compatibility with polymer matrices many functionalizations were proposed, like with silyls, various groups (-COOH, -CO-CH2CH2NH2, -CHO, -NH2, -OH), -Mn, -CuNiCO and -Cu ferrite and REE IIPs, ILs, TEOS/EDA, AEP. Optimal parameters were determined using the batch adsorption method, and then analysis was carried out using the high-pressure method with a synthetic mixture of ions. It was found that the most promising results were obtained for hybrid membranes based on modified chitosan, REE IIPs and the increasing addition of MWCNT-REE IIPs, MWCNT-ILs Cyphos and MWCNT-AEP (for Nd ions: highest value of Kd (2772ml/g) and k from 41-60 regarding other REEs). They showed a high rejection of elements that are components of the matrix in the extracts of coal fly ashes. The REE ions were recovered in amount from 65.62% to 88.32%, which is increasing with amount of additive. While, retention ratio for these ions was from 80.95 to 94.35%, depending on analyzed REE ion and increasing with MWCNT addition. In the case of using modified MWCNTs as adsorbents for REE recovery from solutions, the highest adsorption capacities were demonstrated by MWCNTs modified with -TEOS/EDA, -AEP, -IL Cyphos, -TEOS/APTES, -NH2, -CuNiConFerrite and -Mn Ferrite, reaching up to 20mg/g. In addition, the REE recovery for some MWNTs reached 90% and even 92%. In terms of material characteristics, it was possible to obtain sorbents and membranes with increased magnetic properties (improvement of additives dispersion in polymer matrix and enhance the interaction between phases) and thermal and mechanical stability that can be used repeatedly. After 5 cycles of desorption-sorption the membranes continued to function, that indicates the possibility of potential use of synthesized hybrid membranes based on IIPs and modified MWCNTs as adsorptive materials for REE recovery.