Date of Award
12-17-2023
Document Type
Thesis
Abstract
The advancement toward green energy, the development of precise weaponry, and the conquest of space have made the consumption of rare earth elements and critical elements supersede their production. Rare earth elements are vital and critical for modern technology. Rare earth elements consist of Scandium, Yttrium, and the fifteen elements in the Lanthanide group. These elements are mainly categorized into two types based on their atomic number: Light Rare Earth Elements (LREE) and Heavy Rare Earth Elements (HREE). The conventional methods of extracting economic rare earth elements are widely known, and these methods are found in abundance. However, considering the critical nature of rare earth elements, and the challenge to avoid environmental degradation, finding an alternate method of extracting rare earth elements that is both economically and eco-friendly is needed to overcome the disruption in demand and supply of these elements. One of the many potential methods of rare earth elements extraction is bioleaching or bio-recovery using bacteria, fungi, and archaea. This method has drawn the attention of several researchers in the quest for sustainable and feasible extraction techniques of rare earth elements and other critical elements (CEs). Bio-recovery or bioleaching as compared to physicochemical methods is considered one of the most promising techniques for recovering critical elements. A specific type of bacterial strain the Shewanella oneidensis MR-1 was incubated with rock samples from two distinct locations (North Pole Hills and the Prince of Wales Island) to recover rare earth elements. The experiment was performed under standardized conditions to ensure the reliability of the results. Three major parameters such as the process duration, particle size, and incubation period were tested to evaluate their impact on the recovery process. A total recovery of 30.85 ppb and 7.6 ppb at North Pole Hills and Prince of Wales Island, respectively. The process duration parameter was found to be irrelevant throughout the experiment and the effect of particle sizes ranging below 150 Mesh shows a positive response to the bio-recovery processes compared to particle sizes ranging between +-0.5mm. Maximum recovery was recorded with the samples from North Pole Hills compared to the samples from the Prince of Wales Island. The Bioleaching process was compared with the traditional acid leaching process, and a total of 291.73 ppb was recovered from the North Pole Hills and 107.75 ppb at the Prince of Wales Island. This experiment sets a road map to understand the microbial interaction on hard rock with varying sample sizes and process time.
Recommended Citation
Kebe, Moustapha, "Biorecovery of rare earth elements from hard rock, extraction and analysis" (2023). Engineering . 510.
https://ualaska.researchcommons.org/uaf_grad_engineering/510
Handle
http://hdl.handle.net/11122/14960