Subsurface Characterization of Critical Minerals Using Down Hole Logging Equipment

The measurement of the abundance of critical minerals, including rare earth elements, is limited to laboratory analysis methods that are expensive and require multiple weeks to provide results. Technologies for extracting and refining critical minerals are well underway in the pursuit of creating a domestic supply chain. The challenge is to be able to define critical mineral resources that will provide the critical mineral recovery technologies with a consistent reliable feedstock. This proposal will develop algorithms to estimate rare earth elements and other critical mineral concentrations in subsurface coal formations based on downhole logging tools. Microbeam Technologies Inc. has developed predictive algorithms for on-line or in-situ analysis equipment including x-ray fluorescence and prompt gamma neutron activation to estimate rare earth elements and critical minerals in coal bearing regions. This technology will improve resource evaluation efforts through the ability to provide real-time or near real-time estimations of critical minerals that can guide core drilling efforts and will reduce the cost required to estimate the distribution of critical minerals in subsurface formations. In Phase I, Microbeam will conduct a field test at an active mine in North Dakota to collect drill core samples and downhole logging data of multiple drill holes intersecting multiple coal seams. The drill core samples will be prepared and submitted for trace elemental analysis to get laboratory measurements of critical mineral concentrations throughout the depth of each seam. The laboratory critical mineral data and downhole logging results will be used to develop the predictive algorithms through statistical correlations and neural network training. Some results will be withheld from training efforts and will be used as challenge samples to test the accuracy of the developed algorithms. The predictive algorithms will be used to evaluate historical data from the mining partner to understand the potential resource and compare against historic critical mineral data. Finally, a prototype of the algorithm that can be marketed as a service by Microbeam and licensed to downhole logging companies will be produced. This technology will originally be developed for lignite and associated clays and sediments from North Dakota. Future applications will include other coal and sediment types. Hard rock applications will also be evaluated to understand the application of this technology for estimating critical minerals in deposits like monazite and bastnaesite.