Comparison of Three Approaches for Bioleaching of Rare Earth Elements from Bauxite

Abstract

Approximately 300 million tonnes of bauxite are processed annually, primarily to extract alumina, and can contain moderate rare earth element (REE) concentrations, which are critical to a green energy future. Three bioleaching techniques (organic acid, reductive and oxidative) were tested on three karst bauxites using either Aspergillus sp. (organic acid bioleaching) or Acidithiobacillus ferrooxidans (reductive and oxidative bioleaching). Recovery was highest in relation to middle REE (generally Nd to Gd), with maximum recovery of individual REE between 26.2% and 62.8%, depending on the bauxite sample. REE recovery occurred at low pH (generally < 3), as a result of organic acids produced by Aspergillus sp. or sulphuric acid present in A. ferrooxidans growth media. Acid production was seen when A. ferrooxidans was present. However, a clear increase in REE recovery in the presence of A. ferrooxidans (compared to the control) was only seen with one bauxite sample (clay-rich) and only under oxidative conditions. The complex and varied nature of REE-bearing minerals in bauxite provides multiple targets for bioleaching, and although the majority of recoverable REE can be leached by organic and inorganic acids, there is potential for enhanced recovery by bioleaching.

Microbial recovery of rare earth elements from various waste sources: a mini review with emphasis on microalgae

“… Biosorption batch, 10d, 30 °CC Breuker et al ( 2020 ) Preference for: Nd, Gd, Gy, Lu Fusarium sp. Biosorption batch, 2–4 d, 30 °CC Breuker et al ( 2020 ) heavy REEs Escherichia coli Biosorption batch, 30 min, 37 °CC Takahashi et al ( 2005 ) Park et al ( 2020 ) La, Eu, Yb Pseudomonas aeruginosa Biosorption batch, 30 °CC, pH5 Texier et al ( 1999 ) Nd Kluyveromyces marxianus Candida colliculosa Debaromyces hansenii Saccharomyces cerevisiae Biosorption Biosorption Biosorption Biosorption batch, pH1 batch, pH1 batch, pH1 batch, pH1 Vlachou et al ( 2009 ) Ce; REEs from industry wastes Aspergillus niger Aspergillus flavus Bacillus licheniformis Biosorption; Bioleaching Bioleaching Bioleaching Bioleaching batch, 10d, 30 °CC, pH5 batch, 3d, 28 °CC, pH2 batch, 3d, 28 °CC, pH2 batch, 25 °CC, pH2 semicontinuous, 4d, 30 °CC, pH5.3 Cheng et al ( 2022 ) Sallam et al ( 2014 ) Barnett et al ( 2020 ) Bahaloo-Horeh and Mousavi ( 2022 ) Shen et al ( 2023 ) Ma et al ( 2023 ) Castro et al ( 2023b ) La, Ce Agrobacterium sp. HN1 Biosorption ...…”

Application Prospect of Anaerobic Reduction Pathways in Acidithiobacillus ferrooxidans for Mine Tailings Disposal: A Review

“…Experiments carried out with a sample in which rare-earth-element-containing minerals were occluded by anaerobic reductive bioleaching showed a much greater extraction of the rare-earth following a reductive pre-treatment [64]. Barnett, Palumbo-Roe et al compared three approaches for the bioleaching of rare-earth elements from bauxite [65]. The presence of At.…”

Progress, Challenges, and Perspectives of Bioleaching for Recovering Heavy Metals from Mine Tailings

“…Various rare earth elements can also be recovered effectively by using a high Eh and low pH leaching solution [82]. Bauxite contains complex and diverse rare earth elements, and organic acid bioleaching, reductive bioleaching, and oxidizing bioleaching were used in one study to recover its rare earth element content; the final recovery rate for the rare earth elements from neodymium to gadolinium was the highest, and the leaching rate of single rare earth elements ranged between 26.2% and 62.8% [83]. Furthermore, rare earth elements are also present in coal combustion residual fly ash and in one study were extracted from fly ash by Candida bombicola, Phanerochaete Chrysosporium, and Cryptococcus curvatus [84].…”