SECONDARY AND UNCONVENTIONAL RESOURCE CHARACTERIZATION AND ESTIMATION BEST PRACTICES: LESSONS LEARNED FROM THE CORE-CM INITIATIVE

The Carbon Ore, Rare Earth, and Critical Minerals (CORE-CM) Initiative for U.S. Basins is a Department of Energy (DOE) effort aimed at catalyzing economic growth and job creation by developing more stable supplies of critical minerals and materials (CMM), including novel high-value, nonfuel, carbon-based products as part of our next generation of domestic materials from secondary and unconventional feedstocks. DOE formed collaborative working groups with the CORE-CM awardees and their partners consisting of industry; universities; Local, State, and Federal government personnel; and Tribal governments. Drawing on the experience of technical experts, including the U.S. Geological Survey, DOE developed a characterization guidance document for secondary and unconventional CMM feedstocks that includes best practices for sample collection, field and laboratory analysis, and, of particular interest here, resource assessment and site prioritization. Feedstocks included coal and coal refuse, coal fly ash, and acid mine drainage.

Quantitative assessments of secondary and unconventional sources have previously relied on estimating CMM potential by using average concentration multiplied by approximate volume of feedstock. Many conversations were held by the working group participants pertaining to resource assessments, and it was determined that understanding and constraining uncertainty, as well as being transparent in how the resource was estimated, were of upmost importance regardless of the methodology that was employed (e.g., deterministic vs probabilistic).

Further, while estimated resource potential is a significant step in determining which site should be developed, it is not the only factor. Therefore, the best practices guidance document also explored what additional qualitative and quantitative factors are necessary when considering the prioritization of sites that warrant additional exploration. These factors included ease of extraction of materials, viability of development, and community impact and perception, to name a few.

It is anticipated these efforts will build foundational knowledge for current and future application to developing secondary and unconventional feedstocks and promoting the diversification and resiliency of U.S. CMM supply chains while providing critical contributions to meet the goal of a circular CMM economy.