Team:Bonn-Rheinbach/Implementation
Project
Implementation
What Is and What Could Be
The commonly practiced process of extracting rare earth elements (REEs) is a long and heavily chemical-based approach of extraction [1][2]. Depending on the ore that is used, different approaches are considered. These approaches include electrostatic separation, froth flotation, solvent extraction method as well as resin extraction method, which constitute the most practiced ones[2][3][4]. Most techniques require multiple steps using not only acids but bases as well, which result in these not being environmental-friendly and end up not being sustainable[2][5]. When ores either containing a low concentration or higher concentration of REEs are utilized, they need to go under further processing in order to be ready for the extraction process[4]. In conclusion, multiple techniques are used in order to maximize the concentration and extraction of pure REEs, consequently increasing the general amount of chemicals used.
To avoid the issue of repeated and wasteful uses of chemicals, we want to substitute these with the protein lanmodulin (LanM). Lanmodulin (LanM) is a protein with high binding affinity to lanthanides [6], which makes the protein a better alternative to these chemical based procedures and therefore gives it an advantage to the commonly used techniques. Moreover, the production of the protein is based on genetically engineered bacteria which is convenient for large-scale production. Additionally, LanM allows industrial plants, such as metallurgy plants, REE extraction plants as well as REE refining facilities[4], the opportunity of reducing their waste by replacing most chemical-based approaches with LanM. Furthermore, LanM can be reused for multiple cycles [6], thus adding a huge advantage to the aspect of recyclability. The bacteria used to produce the protein, Escherichia coli BL21 (D3) (E. coli BL21 (D3)), is also safe to use, since it is non-pathogenic, non-hazardous to the environment, and classified as a biosafety level 1 (BSL 1) organism [7].
LanM can not only be used to substitute potentially toxic chelators in the ore processing industry. Due to its extremely high binding affinity down to picomolar concentrations [6], many more fields of applications open up for Biolan. Other up until now barely or not at all considered sources could be used as feedstock. A few examples of these sources are electronic waste (see Partnership or directly iGEM Calgary), sewage, or production waste from the ore processing plants.
written by Nuray Ceyhan
References:
[1] Izatt, R. M. et al. (2014) ‘Challenges to achievement of metal sustainability in our high-tech society’, Chemical Society Reviews, 43(8), pp. 2451–2475. doi: 10.1039/c3cs60440c.
[2] http://metalpedia.asianmetal.com/metal/rare_earth/extraction.shtml
[3] Lyon, K. et al. (2016) ‘ENHANCED SEPARATION OF RARE 2016 International Mineral Processing’, 2016 International Mineral Processing Congress.
[4] Pecharsky, Vitalij K. , Gschneidner, Karl A. and Jr., . "Rare-earth element". Encyclopedia Britannica, 17 Jan. 2019, https://www.britannica.com/science/rare-earth-element. Accessed 21 October 2021.
[5] Schelter, E., Cole, B. and Carroll, P. (2016) Rare earth elements: Purification, sustainability and recycling, Abstracts of Papers of the American Chemical Society.
[6] Deblonde, G.J.-P.; Mattocks, J.A.; Park, D.W.; Reed, D.W.; Cotruvo, J.A.; Jiao, Y. (2020): Selective and Efficient Biomacromolecular Extraction of Rare-Earth Elements using Lanmodulin. In Inorganic Chemistry 59: 11855-11867
[7] Safety Data Sheet for BL21(DE3) Competent E.coli (C2527) EU, New England Biolabs