Critical Rare Earth Element Recovery from Coal Ash Using Microsphere Flower Carbon

Abstract

There is a need to develop new solid-phase adsorbents to extract elements from the coal ash. High surface area carbon adsorbents are remarkably good at adsorption of rare earth elements and have good stability in acidic media. A high surface area (1162 m 2 /g), surface-oxidized microsphere flower carbon (MFC-O) has been prepared for the extraction of rare earth elements as well as thorium and uranium. MFC-O exhibits outstanding distribution coefficients up to k d = 1.2 × 10 6 for thorium, uranium, and rare earth elements. It was found that thorium and uranium can be separated from the rare earth elements by adjusting the pH. The maximum extraction capacity (71.3 mg/g) was performed up to 88 ppm with 18 competitive elements (Sc,

Rationally designed nanotrap structures for efficient separation of rare earth elements over a single step

“…20 - 26 , and Supplementary Table 3 ). This greatly exceeds the capacity of most current adsorbents, such as CA@Fe 3 O 4 NPs 35 , KIT-6-1,3-PDDA 36 , MFC-O 37 , MIL-101-DGA 38 , and PEI800/ES-1/2.1 39 . Energy dispersive X-ray spectroscopy (EDS) mapping analysis confirms that Pr 3+ , Nd 3+ , Gd 3+ , and Dy 3+ entered the structures of the material with a uniform distribution throughout the samples (Supplementary Fig.…”

Rationally designed nanotrap structures for efficient separation of rare earth elements over a single step

“…This greatly exceeds the capacity of most current adsorbents, such as CA@Fe 3 O 4 NPs 35 , KIT-6-1,3-PDDA 36 , MFC-O 37 , and PEI800/ES-1/2.1 38 . Energy dispersive X-ray spectroscopy (EDS) mapping analysis con rms that Pr 3+ , Nd 3+ , Gd 3+ , and Dy 3+ were entered the structures of the material with a uniform distribution throughout the samples (Supplementary Fig.…”

Adsorption-based Separation and Recovery of Rare Earth Elements

“…Diphonix was used to extract REE from the nitric acid solution from apatite processing on a pilot scale at Akron public corporation (Ehrlich & Lisichkin, 2017). However, there are lab studies in literature where various adsorbents have been used to separate REEs from various natural samples such as bauxite mud (Hu et al, 2019;Ochsenkühn-Petropulu et al, 1995;Roosen et al, 2016;ZHOU et al, 2008); Silicate & niobium mining deposits (Hu et al, 2017); apatite, orthite, and slag (Kostenko et al, 2019;Ogata et al, 2016); bastnäsite (Dolak et al, 2015), acidic mine drainage (Hermassi et al, 2021;Ramasamy et al, 2019;Ramasamy, Puhakka, Iftekhar, et al, 2018;; spiked seawater (Callura et al, 2018;Noack et al, 2016); spiked river/groundwater and sewage water (Marwani et al, 2018;Yantasee et al, 2009); geothermal brines , acidic streams, dialysate (Yantasee et al, 2009); REE mineral leachate (Giret et al, 2018); industrial wastewater (Li et al, 2013); leached solution of spent Ni-MH cells (Gasser & Aly, 2013;Ko lodyńska et al, 2019), thin-film phosphors leached solution (Schaeffer et al, 2017), phosphoric acid plant effluent (Al-Thyabat & Zhang, 2015), zinc mine ore (Fonseka et al, 2021), and coal fly ash (Brown & Balkus, 2021;Hovey et al, 2021;Mondal et al, 2019). These adsorbents showed varying degrees of success for REEs extraction (Figure 4).…”