NOFO_DE-FOA-0003592_ROCKS.pdf

Questions about this NOFO? Check the Frequently Asked Questions available at https://arpa-e.energy.gov/faqs. For questions that have not already been answered, email ARPA-E-CO@hq.doe.gov (with NOFO name and number in subject line). Problems with ARPA-E eXCHANGE? Email ExchangeHelp@hq.doe.gov (with NOFO name and number in subject line).

AR-311-05.25

FINANCIAL ASSISTANCE

NOTICE OF FUNDING OPPORTUNITY

ADVANCED RESEARCH PROJECTS AGENCY – ENERGY (ARPA-E)

U.S. DEPARTMENT OF ENERGY

RELIABLE ORE CHARACTERIZATION WITH

KEYSTONE SENSING (ROCKS)

Announcement Type: Initial Announcement

Notice of Funding Opportunity No. DE-FOA-0003592 Assistance Listing Number 81.135

NOFOs are posted on ARPA-E eXCHANGE (https://arpa-e-foa.energy.gov/), Grants.gov (http://www.grants.gov/), and FedConnect (https://www.fedconnect.net/FedConnect/). Any modifications to the NOFO are also posted to these websites. You can receive an e-mail when a modification is posted by registering with FedConnect as an interested party for this NOFO. It is recommended that you register as soon as possible after release of the NOFO to ensure that you receive timely notice of any modifications or other announcements.

https://arpa-e.energy.gov/faqs mailto:ARPA-E-CO@hq.doe.gov mailto:ExchangeHelp@hq.doe.gov https://arpa-e-foa.energy.gov/ http://www.grants.gov/ https://www.fedconnect.net/FedConnect/

Questions about this NOFO? Check the Frequently Asked Questions available at https://arpa-e.energy.gov/faqs. For questions that have not already been answered, email ARPA-E-CO@hq.doe.gov (with NOFO name and number in subject line). Problems with ARPA-E eXCHANGE? Email ExchangeHelp@hq.doe.gov (with NOFO name and number in subject line).

TABLE OF CONTENTS

BASIC INFORMATION ......................................................................................................................................... - 5 - I. FUNDING OPPORTUNITY DESCRIPTION ..................................................................................................... - 7 -

A. AGENCY OVERVIEW ........................................................................................................................................... - 7 - B. PROGRAM OVERVIEW........................................................................................................................................ - 9 -

1. MINE DEVELOPMENT ................................................................................................................................... - 9 -

2. TECHNICAL BACKGROUND AND CHALLENGES .................................................................................................. - 11 -

C. PROGRAM OBJECTIVES ................................................................................................................................ - 12 - D. TECHNICAL CATEGORIES OF INTEREST ............................................................................................................. - 12 -

1. CATEGORY A: DRILLING TECHNOLOGY .......................................................................................................... - 13 -

2. CATEGORY B: SENSING AND ANALYSIS .......................................................................................................... - 13 -

3. CATEGORY C: OTHER ................................................................................................................................. - 14 -

E. TECHNICAL PERFORMANCE TARGETS .................................................................................................................. - 15 -

1. CATEGORY A: DRILLING TECHNOLOGY .......................................................................................................... - 17 -

2. CATEGORY B: SENSING AND ANALYSIS .......................................................................................................... - 18 -

3. CATEGORY C: OTHER ................................................................................................................................. - 18 -

F. STATEMENT OF SUBSTANTIAL INVOLVEMENT ....................................................................................................... - 19 - G. FUNDING RESTRICTIONS .............................................................................................................................. - 20 -

1. ALLOWABLE COSTS .................................................................................................................................... - 20 -

2. PRE-AWARD COSTS ................................................................................................................................... - 20 -

3. PATENT COSTS .......................................................................................................................................... - 20 -

4. CONSTRUCTION ......................................................................................................................................... - 21 -

5. FOREIGN TRAVEL ....................................................................................................................................... - 21 -

6. PERFORMANCE OF WORK IN THE UNITED STATES............................................................................................ - 21 -

7. PURCHASE OF NEW EQUIPMENT .................................................................................................................. - 21 -

8. TECHNOLOGY TRANSFER AND OUTREACH ...................................................................................................... - 22 -

9. LOBBYING ................................................................................................................................................ - 22 -

10. CONFERENCE SPENDING ............................................................................................................................. - 23 -

11. INDEPENDENT RESEARCH AND DEVELOPMENT COSTS....................................................................................... - 23 -

12. BUY AMERICA REQUIREMENT FOR PUBLIC INFRASTRUCTURE PROJECTS .............................................................. - 24 -

13. REQUIREMENT FOR FINANCIAL PERSONNEL .................................................................................................... - 24 -

14. PARTICIPANTS, COLLABORATING ORGANIZATIONS, AND CURRENT AND PENDING SUPPORT ................................... - 24 -

15. MAXIMUM LIMIT ON INDIRECT COSTS .......................................................................................................... - 25 -

II. ELIGIBILITY INFORMATION ...................................................................................................................... - 26 - A. ELIGIBLE APPLICANTS ....................................................................................................................................... - 26 -

1. INDIVIDUALS ............................................................................................................................................. - 26 -

2. DOMESTIC ENTITIES ................................................................................................................................... - 26 -

3. CONSORTIA .............................................................................................................................................. - 27 -

4. FOREIGN NATIONAL PARTICIPATION FROM COUNTRIES OF CONCERN ................................................................. - 27 -

5. FOREIGN PARTICIPATION CONSIDERATIONS ................................................................................................... - 28 -

B. COMPLIANCE AND RESPONSIVENESS ................................................................................................................... - 28 - C. LIMITATION ON NUMBER OF SUBMISSIONS ..................................................................................................... - 28 - D. COST SHARING ........................................................................................................................................... - 29 -

1. BASE COST SHARE REQUIREMENT ................................................................................................................ - 29 -

2. INCREASED COST SHARE REQUIREMENT ........................................................................................................ - 29 -

3. REDUCED COST SHARE REQUIREMENT .......................................................................................................... - 29 -

4. LEGAL RESPONSIBILITY ............................................................................................................................... - 30 -

5. COST SHARE ALLOCATION ........................................................................................................................... - 30 -

6. COST SHARE TYPES AND ALLOWABILITY ........................................................................................................ - 30 -

7. COST SHARE CONTRIBUTIONS BY FFRDCS AND GOGOS .................................................................................. - 31 -https://arpa-e.energy.gov/faqs mailto:ARPA-E-CO@hq.doe.gov mailto:ExchangeHelp@hq.doe.gov

Questions about this NOFO? Check the Frequently Asked Questions available at https://arpa-e.energy.gov/faqs. For questions that have not already been answered, email ARPA-E-CO@hq.doe.gov (with NOFO name and number in subject line). Problems with ARPA-E eXCHANGE? Email ExchangeHelp@hq.doe.gov (with NOFO name and number in subject line).

8. COST SHARE VERIFICATION ......................................................................................................................... - 32 - III. APPLICATION CONTENTS AND FORMAT .............................................................................................. - 33 -

A. GENERAL APPLICATION CONTENT REQUIREMENTS ................................................................................................ - 33 -

1. MARKING OF CONFIDENTIAL INFORMATION ................................................................................................... - 33 -

2. EXPORT CONTROL INFORMATION ................................................................................................................. - 33 -

B. CONCEPT PAPERS ............................................................................................................................................ - 34 -

1. FIRST COMPONENT: CONCEPT PAPER............................................................................................................ - 34 -

2. SECOND COMPONENT: SUMMARY SLIDE ....................................................................................................... - 34 -

C. FULL APPLICATIONS .................................................................................................................................... - 35 -

1. FIRST COMPONENT: TECHNICAL VOLUME ...................................................................................................... - 35 -

2. SECOND COMPONENT: SF-424 ................................................................................................................... - 35 -

3. THIRD COMPONENT: BUDGET JUSTIFICATION WORKBOOK/SF-424A ................................................................ - 36 -

4. FOURTH COMPONENT: SUMMARY FOR PUBLIC RELEASE .................................................................................. - 36 -

5. FIFTH COMPONENT: SUMMARY SLIDE ........................................................................................................... - 37 -

6. SIXTH COMPONENT: BUSINESS ASSURANCES & DISCLOSURES FORM .................................................................. - 37 -

D. REPLIES TO REVIEWER COMMENTS ................................................................................................................ - 37 - IV. SUBMISSION REQUIREMENTS AND DEADLINES ................................................................................... - 39 -

A. UNIQUE ENTITY IDENTIFIER AND SAM REGISTRATION ........................................................................................... - 39 - B. USE OF ARPA-E EXCHANGE .......................................................................................................................... - 40 - C. REQUIRED DOCUMENTS CHECKLIST AND DEADLINES ......................................................................................... - 41 - D. COMPLIANCE ............................................................................................................................................. - 41 - E. INTERGOVERNMENTAL REVIEW ......................................................................................................................... - 42 -

V. APPLICATION REVIEW INFORMATION ..................................................................................................... - 43 - A. RESPONSIVENESS ............................................................................................................................................ - 43 -

1. TECHNICAL RESPONSIVENESS REVIEW ........................................................................................................... - 43 -

2. SUBMISSIONS SPECIFICALLY NOT OF INTEREST ................................................................................................. - 44 -

B. REVIEW CRITERIA ............................................................................................................................................ - 44 -

1. CRITERIA FOR CONCEPT PAPERS ................................................................................................................... - 44 -

2. CRITERIA FOR FULL APPLICATIONS ................................................................................................................ - 45 -

3. CRITERIA FOR REPLIES TO REVIEWER COMMENTS ............................................................................................ - 46 -

C. PROGRAM POLICY FACTORS ......................................................................................................................... - 46 - D. REVIEW AND SELECTION PROCESS ................................................................................................................. - 47 -

1. CONCEPT PAPERS ...................................................................................................................................... - 47 -

2. FULL APPLICATIONS ................................................................................................................................... - 47 -

3. REPLY TO REVIEWER COMMENTS ................................................................................................................. - 48 -

4. PRE-SELECTION CLARIFICATIONS AND “DOWN-SELECT” PROCESS ...................................................................... - 48 -

5. SELECTION FOR AWARD NEGOTIATIONS ........................................................................................................ - 48 -

E. ARPA-E REVIEWERS ....................................................................................................................................... - 49 - F. ARPA-E SUPPORT CONTRACTORS ..................................................................................................................... - 49 - G. RISK REVIEW.............................................................................................................................................. - 49 - H. DUE DILIGENCE REVIEW FOR RESEARCH, TECHNOLOGY AND ECONOMIC SECURITY ................................................. - 50 -

VI. AWARD NOTICES AND AWARD TYPES ................................................................................................. - 52 - A. AWARD NOTICES ............................................................................................................................................ - 52 -

1. REJECTED SUBMISSIONS ............................................................................................................................. - 52 -

2. CONCEPT PAPER NOTIFICATIONS .................................................................................................................. - 52 -

3. FULL APPLICATION NOTIFICATIONS ............................................................................................................... - 52 -

B. PRE-AWARD COSTS ......................................................................................................................................... - 53 - C. RENEWAL AWARDS ..................................................................................................................................... - 54 - D. FUNDING AGREEMENT TYPES ....................................................................................................................... - 54 -https://arpa-e.energy.gov/faqs

Questions about this NOFO? Check the Frequently Asked Questions available at https://arpa-e.energy.gov/faqs. For questions that have not already been answered, email ARPA-E-CO@hq.doe.gov (with NOFO name and number in subject line). Problems with ARPA-E eXCHANGE? Email ExchangeHelp@hq.doe.gov (with NOFO name and number in subject line).

1. COOPERATIVE AGREEMENTS........................................................................................................................ - 54 -

2. FUNDING AGREEMENTS WITH FFRDCS/DOE LABS, GOGOS, AND FEDERAL INSTRUMENTALITIES .......................... - 54 -

3. OTHER TRANSACTIONS AUTHORITY .............................................................................................................. - 55 -

VII. POST-AWARD REQUIREMENTS AND ADMINISTRATION ...................................................................... - 56 - A. NATIONAL POLICY REQUIREMENTS .................................................................................................................... - 56 -

1. NATIONAL POLICY ASSURANCES ................................................................................................................... - 56 -

2. ENVIRONMENTAL IMPACT QUESTIONNAIRE ................................................................................................... - 56 -

B. ADMINISTRATIVE REQUIREMENTS ...................................................................................................................... - 57 -

1. COST SHARE PAYMENTS ............................................................................................................................. - 57 -

2. INTELLECTUAL PROPERTY AND DATA MANAGEMENT PLANS ............................................................................. - 57 -

3. U.S. COMPETITIVENESS .............................................................................................................................. - 58 -

4. NONDISCLOSURE AND CONFIDENTIALITY AGREEMENTS REPRESENTATIONS .......................................................... - 59 -

5. INTERIM CONFLICT OF INTEREST POLICY FOR FINANCIAL ASSISTANCE .................................................................. - 60 -

6. COMPLIANCE AUDIT REQUIREMENT .............................................................................................................. - 60 -

7. RESEARCH SECURITY TRAINING REQUIREMENT ............................................................................................... - 61 -

C. REPORTING................................................................................................................................................ - 61 -

1. FRAUD, WASTE, AND ABUSE ....................................................................................................................... - 61 -

2. COMMERCIALIZATION PLAN AND SOFTWARE REPORTING ................................................................................. - 61 -

VIII. OTHER INFORMATION ......................................................................................................................... - 62 - A. TITLE TO SUBJECT INVENTIONS .......................................................................................................................... - 62 - B. GOVERNMENT RIGHTS IN SUBJECT INVENTIONS.................................................................................................... - 62 -

1. GOVERNMENT USE LICENSE ........................................................................................................................ - 63 -

2. MARCH-IN RIGHTS .................................................................................................................................... - 63 -

C. RIGHTS IN TECHNICAL DATA ......................................................................................................................... - 63 - D. PROTECTED PERSONALLY IDENTIFIABLE INFORMATION ...................................................................................... - 64 -

IX. GLOSSARY ........................................................................................................................................... - 65 -https://arpa-e.energy.gov/faqs

Questions about this NOFO? Check the Frequently Asked Questions available at https://arpa-e.energy.gov/faqs. For questions that have not already been answered, email ARPA-E-CO@hq.doe.gov (with NOFO name and number in subject line). Problems with ARPA-E eXCHANGE? Email ExchangeHelp@hq.doe.gov (with NOFO name and number in subject line).

- 5 -

BASIC INFORMATION

KEY DATES:

Notice of Funding Opportunity (NOFO) Issue Date: August 25, 2025 Deadline for Concept Paper Questions to ARPA-E- CO@hq.doe.gov:

5 PM ET, September 15, Submission Deadline for Concept Papers: 9:30 AM ET, September 25, Anticipated Date for Encourage/Discourage Notifications: 5 PM ET, October 30, 2025 Deadline for Full Application Questions to ARPA-E- CO@hq.doe.gov:

5 PM ET, TBD

Submission Deadline for Full Applications: 9:30 AM ET, TBD Expected Reviewer Comment Release Date: 5 PM ET, TBD Submission Deadline for Replies to Reviewer Comments: 5 PM ET, TBD Anticipated Timeframe for Selection Notifications: February 2026 Anticipated Timeframe for Award: June 2026 Anticipated Period of Performance: June 2026 – June 2029

BASIC INFORMATION:

Total Amount to Be Awarded

Approximately $40 million, subject to the availability of appropriated funds to be shared between NOFOs DE-FOA-0003592 and DE-FOA-0003593.

Anticipated Number and Value of Awards

ARPA-E anticipates making approximately 10-12 awards between NOFOs DE-FOA-0003592 and DE-FOA-0003593. ARPA-E may issue one, multiple, or no awards under this NOFO. The Federal share of awards under this NOFO may vary between $2 million and $5 million.

Agency Contact Information

• Questions and answers (Q&As) about ARPA-E and this specific NOFO:

http://arpa-e.energy.gov/faq.

• Send other questions about the NOFO to: ARPA-E-CO@hq.doe.gov.

• Send questions about use of ARPA-E eXCHANGE to:

ExchangeHelp@hq.doe.gov.

Upon the issuance of a NOFO, only the Grants Officer via ARPA-E- CO@hq.doe.gov may communicate with Applicants. This “quiet period” remains in effect until ARPA-E’s public announcement of project selections.

Emails sent to other email addresses will be disregarded.

This program aims to accelerate U.S. mineral independence by increasing long-term U.S. production of rare earth elements (REEs) and critical minerals.1,2,3 The program will support transformative innovations in drilling, sensing, and analytical technologies to enable rapid, high-resolution, and cost-effective assessment of ore deposits with

1 “Immediate Measures to Increase American Mineral Production.” The White House, March 20, 2025.

https://www.whitehouse.gov/presidential-actions/2025/03/immediate-measures-to-increase-american-mineral-production/.

2 In this document, the term “critical mineral” refers to the following definition for “mineral” found in ref. 1, Sec. 2 (a) “Mineral” means a critical mineral, as defined by 30 U.S.C. 1606(a)(3), as well as uranium, copper, potash, gold, and any other element, compound or material as determined by the Chair of the National Energy Dominance Council (NEDC).

3 Van Gosen, Bradley S., Philip L. Verplanck, and Poul Emsbo. “Rare Earth Element Mineral Deposits in the United States.” Circular, 2019. https://doi.org/10.3133/cir1454.

https://arpa-e.energy.gov/faqs mailto:ARPA-E-CO@hq.doe.gov mailto:ExchangeHelp@hq.doe.gov mailto:ARPA-E-CO@hq.doe.gov mailto:ARPA-E-CO@hq.doe.gov mailto:ARPA-E-CO@hq.doe.gov mailto:ARPA-E-CO@hq.doe.gov http://arpa-e.energy.gov/faq mailto:ARPA-E-CO@hq.doe.gov mailto:ExchangeHelp@hq.doe.gov

Questions about this NOFO? Check the Frequently Asked Questions available at https://arpa-e.energy.gov/faqs. For questions that have not already been answered, email ARPA-E-CO@hq.doe.gov (with NOFO name and number in subject line). Problems with ARPA-E eXCHANGE? Email ExchangeHelp@hq.doe.gov (with NOFO name and number in subject line).

- 6 -reduced uncertainty. These innovations are expected to deliver significant improvements in orebody delineation and characterization.

While the program’s emphasis is on subsurface hard rock resources, technologies for rapidly evaluating resources found in alternate (e.g., REE-enriched clays, placer deposits) or untapped (e.g., seafloor) resources are also of interest.4

4 “Unleashing America’s Offshore Critical Minerals and Resources.” The White House, April 24, 2025.

https://www.whitehouse.gov/presidential-actions/2025/04/unleashing-americas-offshore-critical-minerals-and-resources/.

https://arpa-e.energy.gov/faqs

Questions about this NOFO? Check the Frequently Asked Questions available at https://arpa-e.energy.gov/faqs. For questions that have not already been answered, email ARPA-E-CO@hq.doe.gov (with NOFO name and number in subject line). Problems with ARPA-E eXCHANGE? Email ExchangeHelp@hq.doe.gov (with NOFO name and number in subject line).

- 7 -

I. FUNDING OPPORTUNITY DESCRIPTION

A. AGENCY OVERVIEW

The Advanced Research Projects Agency – Energy (ARPA-E), an organization within the Department of Energy (DOE), is chartered by Congress in the America COMPETES Act of 2007 (P.L. 110-69), as amended by the America COMPETES Reauthorization Act of 2010 (P.L. 111-358), as further amended by the Energy Act of 2020 (P.L. 116- 260):

“(A) to enhance the economic and energy security of the United States through the development of energy technologies that—

(i) reduce imports of energy from foreign sources;

(ii) reduce energy-related emissions, including greenhouse gases;

(iii) improve the energy efficiency of all economic sectors;

(iv) provide transformative solutions to improve the management, clean-up, and disposal of radioactive waste and spent nuclear fuel; and

(v) improve the resilience, reliability, and security of infrastructure to produce, deliver, and store energy; and

(B) to ensure that the United States maintains a technological lead in developing and deploying advanced energy technologies.”

ARPA-E issues this Notice of Funding Opportunity (NOFO) under its authorizing statute codified at 42 U.S.C. § 16538. The NOFO and any cooperative agreements or grants made under this NOFO are subject to 2 C.F.R. Part 200 as supplemented by 2 C.F.R.

Part 910.

ARPA-E funds research on, and the development of, transformative science and technology solutions to address the energy and environmental missions of the Department. The agency focuses on technologies that can be meaningfully advanced with a modest investment over a defined period of time in order to catalyze the translation from scientific discovery to early-stage technology. For the latest news and information about ARPA-E, its programs and the research projects currently supported, see: http://arpa-e.energy.gov/.

ARPA-E funds transformational research. Existing energy technologies generally progress on established “learning curves” where refinements to a technology and the economies of scale that accrue as manufacturing and distribution develop drive improvements to the cost/performance metric in a gradual fashion. This continual improvement of a technology is important to its increased commercial deployment and is appropriately the focus of the private sector or the applied technology offices within DOE. In contrast, ARPA-E supports transformative research that has the potential to create fundamentally new learning curves. ARPA-E technology projects typically start with cost/performance estimates well above the level of an incumbent technology.

Given the high risk inherent in these projects, many will fail to progress, but some may succeed in generating a new learning curve with a projected cost/performance metric https://arpa-e.energy.gov/faqs mailto:ARPA-E-CO@hq.doe.gov http://arpa-e.energy.gov/

Questions about this NOFO? Check the Frequently Asked Questions available at https://arpa-e.energy.gov/faqs. For questions that have not already been answered, email ARPA-E-CO@hq.doe.gov (with NOFO name and number in subject line). Problems with ARPA-E eXCHANGE? Email ExchangeHelp@hq.doe.gov (with NOFO name and number in subject line).

- 8 -that is significantly better than that of the incumbent technology. ARPA-E will provide support at the highest funding level only for submissions with significant technology risk, aggressive timetables, and careful management and mitigation of the associated risks.

ARPA-E funds technology with the potential to be disruptive in the marketplace.

The mere creation of a new learning curve does not ensure market penetration. Rather, the ultimate value of a technology is determined by the marketplace, and impactful technologies ultimately become disruptive – that is, they are widely adopted and displace existing technologies from the marketplace or create entirely new markets.

ARPA-E understands that definitive proof of market disruption takes time, particularly for energy technologies. Therefore, ARPA-E funds the development of technologies that, if technically successful, have clear disruptive potential, e.g., by demonstrating capability for manufacturing at competitive cost and deployment at scale.

ARPA-E funds applied research and development (R&D). The Office of Management and Budget defines “applied research” as an “original investigation undertaken in order to acquire new knowledge…directed primarily towards a specific practical aim or objective” and defines “experimental development” as “creative and systematic work, drawing on knowledge gained from research and practical experience, which is directed at producing new products or processes or improving existing products or processes.”5 Applicants interested in receiving financial assistance for basic research (defined by the Office of Management and Budget as “experimental or theoretical work undertaken primarily to acquire new knowledge of the underlying foundations of phenomena and observable facts”)1 should contact the DOE’s Office of Science (http://science.energy.gov/). Office of Science national scientific user facilities (http://science.energy.gov/user-facilities/) are open to all researchers, including ARPA-E Applicants and awardees. These facilities provide advanced tools of modern science including accelerators, colliders, supercomputers, light sources and neutron sources, as well as facilities for studying the nanoworld, the environment, and the atmosphere.

Projects focused on early-stage R&D for the improvement of technology along defined roadmaps may be more appropriate for support through the DOE applied energy offices including: the Office of Energy Efficiency and Renewable Energy (http://www.eere.energy.gov/), the Office of Fossil Energy and Carbon Management (https://www.energy.gov/fecm/office-fossil-energy-and-carbon-management), the Office of Nuclear Energy (http://www.energy.gov/ne/office-nuclear-energy), and the Office of Electricity (https://www.energy.gov/oe/office-electricity).

ARPA-E encourages submissions stemming from ideas that still require proof-of-concept R&D efforts as well as those for which some proof-of-concept demonstration already exists. Submissions can propose a project with the end deliverable being an extremely creative, but partial solution.

5 OMB Circular A-11 (https://www.whitehouse.gov/wp-content/uploads/2018/06/a11_web_toc.pdf), Section 84, pg. 3.

mailto:ARPA-E-CO@hq.doe.gov mailto:ExchangeHelp@hq.doe.gov http://science.energy.gov/ http://science.energy.gov/user-facilities/ http://www.eere.energy.gov/ https://www.energy.gov/fecm/office-fossil-energy-and-carbon-management http://www.energy.gov/ne/office-nuclear-energy https://www.energy.gov/oe/office-electricity

Questions about this NOFO? Check the Frequently Asked Questions available at https://arpa-e.energy.gov/faqs. For questions that have not already been answered, email ARPA-E-CO@hq.doe.gov (with NOFO name and number in subject line). Problems with ARPA-E eXCHANGE? Email ExchangeHelp@hq.doe.gov (with NOFO name and number in subject line).

- 9 -

B. PROGRAM OVERVIEW

Rare earth elements (REEs) and critical minerals are essential for modern energy technologies. REEs are key to high-performance magnets, motors, superconductors, catalysts, transmission, and conversion systems necessary for U.S. energy security.

Affordable and secure domestic critical mineral supply chains will advance future energy competitiveness.6 The U.S. possesses significant domestic resources of REEs and other critical minerals but operates only one productive REE mine.

The development of new mines is a multistage process that typically requires years to complete. Prospect evaluation and feasibility assessment of a hard rock mine can alone take years or even decades. The goal of the Reliable Ore Characterization with Keystone Sensing (ROCKS) program is to develop tools to evaluate the feasibility of an ore deposit in months, rather than years. This will enable rapid scoping of alternate and untapped resources. By accelerating and improving characterization, the program will enable earlier, more accurate, and lower-cost deposit assessments. A transformative increase in this capability will aid not only the development of abundant domestic REE deposits, but that of all critical minerals. Lower-cost, accurate resource characterization will enable more productive mining with less waste rock and streamline the entire mineral processing and refining supply chain.

1. MINE DEVELOPMENT

At a high level, mine development consists of three major phases: (1) prospecting, (2) resource characterization and evaluation, and, if feasible, (3) development leading to ore production.7 Most of the U.S. has been systematically mapped and explored over decades and prospectivity maps can be constructed for almost all minerals.8,9 These prospectivity maps—typically derived from geological models and geophysical data— indicate areas with potential mineral occurrences, often identifying hundreds or thousands of possible targets across thousands of square kilometers. Some of these locations may have active or abandoned mines but a full understanding of the entire resource remains incomplete. This lack of clarity is especially true for resources where ore deposits are covered by hundreds of meters of overlying rock.10

6 Critical Minerals and Materials. Accessed August 6, 2025. https://www.energy.gov/topics/critical-minerals-and-materials.

7 “Phases of Mining.” Resource Capital Funds, August 15, 2024.

https://resourcecapitalfunds.com/insights/mining-and-minerals-101/phases-mining/.

8 “CriticalMAAS: Critical Mineral Assessments with AI Support.” DARPA. Accessed August 6, 2025.

https://www.darpa.mil/research/programs/critical-mineral-assessments-with-ai-support.

9 “Critical Minerals Mapping Initiative (CMMI).” USGS. Accessed August 4, 2025.

https://www.usgs.gov/centers/gggsc/science/critical-minerals-mapping-initiative-cmmi.

10 Ranjith, Pathegama G., Jian Zhao, Minghe Ju, Radhika V.S. De Silva, Tharaka D. Rathnaweera, and Adheesha K.M.S. Bandara. “Opportunities and Challenges in Deep Mining: A Brief Review.” Engineering 3, no. 4 (August 2017): 546–51. https://doi.org/10.1016/j.eng.2017.04.024.

https://arpa-e.energy.gov/faqs

Questions about this NOFO? Check the Frequently Asked Questions available at https://arpa-e.energy.gov/faqs. For questions that have not already been answered, email ARPA-E-CO@hq.doe.gov (with NOFO name and number in subject line). Problems with ARPA-E eXCHANGE? Email ExchangeHelp@hq.doe.gov (with NOFO name and number in subject line).

- 10 -

Evaluation of a prospect requires full three-dimensional (3D) mapping of the subsurface, which is referred to as orebody characterization.11 Orebody characterization relies on detailed structural and mineralogical measurements that can take over a decade to complete and can cost over $100 million per prospect.12,13 This characterization of a deposit relies on extensive drilling, often requiring hundreds of boreholes of continuous rock cores, along with sensing, analysis, and detailed laboratory assays. The core samples provide critical data on ore grade, mineralogy, and rock texture which cannot be accurately measured with remote sensors alone. This data is integrated into preliminary 3D representations of the deposit. Even with dense drilling, orebody properties must be interpolated between boreholes to account for gaps in the data. This introduces uncertainty, especially in complex deposits where mineral veins and alteration zones can be far smaller than typical borehole spacing.

The result of orebody characterization is a 3D block model of the orebody (Figure 1).

Each block (typically with dimensions of approximately 10 meters) represents estimated values of key parameters such as ore grade, tonnage, mineralogy, and recovery factor.14,15 These models are essential to determine the economic potential of a deposit and to guide mine planning. As mining progresses, these models are continuously refined with additional characterization to support operational decisions and long-term resource yield as well as management.

11 “Orebody Modeling and Resource Estimation.” SGS MINERALS SERVICES, July 2008.

https://www.sgs.com/-/media/sgscorp/documents/corporate/brochures/sgs-849-orebody-modelling-and-resource-estimation.cdn.en-CA.pdf.

12 Bullock, Richard L. "Mineral property feasibility studies." SME Mining Handbook 1 (2011).

13 “Ivanhoe Electric’s Preliminary Feasibility Study for the Santa Cruz Copper Project in Arizona Defines a High-Quality Underground Mining Operation with Strong Economics.” Ivanhoe Electric Inc., July 23, 2025.

https://ivanhoeelectric.com/news/ivanhoe-electrics-preliminary-feasibility-study-for-the-santa-cruz-copper-project-in-arizona-defines-a-high-quality-underground/.

14 Fathollahzadeh, Karo, Elham Mardaneh, Mehmet Cigla, and Mohammad Waqar Asad. “A Mathematical Model for Open Pit Mine Production Scheduling with Grade Engineering® and Stockpiling.” International Journal of Mining Science and Technology 31, no. 4 (July 2021): 717–28.

https://doi.org/10.1016/j.ijmst.2021.03.011.

15 “Block Model Knowledge for Mining Engineers - an Introduction.” Deswik. Accessed August 4, 2025.

https://www.deswik.com/whitepapers/block-model-knowledge-for-mining-engineers-an-introduction.

https://arpa-e.energy.gov/faqs

Questions about this NOFO? Check the Frequently Asked Questions available at https://arpa-e.energy.gov/faqs. For questions that have not already been answered, email ARPA-E-CO@hq.doe.gov (with NOFO name and number in subject line). Problems with ARPA-E eXCHANGE? Email ExchangeHelp@hq.doe.gov (with NOFO name and number in subject line).

- 11 -

Figure 1. Example section of a copper deposit block model showing (a) grade and (b) recovery potential.

Grade and recovery potential do not always correlate due to complicated texture and gangue mineralogy.16

2. TECHNICAL BACKGROUND AND CHALLENGES

Drilling technology. At present, borehole drilling and analysis provides the foundation of orebody characterization but remains costly and time-consuming. Mineral exploration drilling is one of the most significant costs in resource characterization. Core drilling rates in hard-rock environments are typically slow, often less than 5 meters per hour (m/hr), at a cost of approximately $100,000 per borehole.17 Many resources are in remote areas, requiring portable rigs that must be transported by truck, barge, or even helicopter. These logistical requirements limit rig size and power, slowing penetration rates. Alternate drilling technologies such as rotary or hammer drilling are much faster but cannot return continuous core, and sample evaluation for these approaches depends on rock chips or cuttings, which provide a poor representation of the downhole environment.

Drilling measurements and logging. Measurement while drilling (MWD) parameters, such as drill penetration rate and weight on bit, are used in assessing geomechanical properties both in the initial evaluation and during blasthole drilling. Borehole logging and geophysical measurements typically consist of techniques such as resistivity, induced polarization, and natural gamma ray. Challenges include adapting logging equipment to the narrower drilled holes typically used in mineral exploration, and in conducting measurements quickly and at low cost.

Core evaluation. The cores pulled out of boreholes are used to measure mineralogy, elemental composition, and rock texture. Although some core evaluations (e.g., manual inspection, hyperspectral imaging, laser spectroscopy, X-ray fluorescence) occur at the

16 Frenzel, Max, Regina Baumgartner, Raimon Tolosana-Delgado, and Jens Gutzmer. “Geometallurgy:

Present and Future.” Elements 19, no. 6 (December 1, 2023): 345–51.

https://doi.org/10.2138/gselements.19.6.345.

17 “Drilling Techniques & Costs.” NOVO Resources. Accessed August 4, 2025.

https://novoresources.com/exploration/glossary/drilling-techniques-costs/.

https://arpa-e.energy.gov/faqs

Questions about this NOFO? Check the Frequently Asked Questions available at https://arpa-e.energy.gov/faqs. For questions that have not already been answered, email ARPA-E-CO@hq.doe.gov (with NOFO name and number in subject line). Problems with ARPA-E eXCHANGE? Email ExchangeHelp@hq.doe.gov (with NOFO name and number in subject line).

- 12 -field site, most high-resolution geochemical and mineralogical data still require offsite laboratory techniques such as inductively-coupled plasma-mass spectrometry, electron microscopy, or other more advanced mineralogical and metallurgical characterization testing. Transport, preparation, and laboratory processing add weeks or months to the characterization effort, leading to significant delays.

Sensing and analysis. While geophysical surveys such as gravity, magnetic, magneto-telluric, electromagnetic, and radiometric methods can provide insights on the subsurface orebody, they cannot resolve most mineralogical variations, especially for REEs. Gamma-ray spectrometry can provide useful indicators for REEs, but its shallow penetration depth limits effectiveness if the orebody is covered by other types of rock.

Further, geophysical analysis is not always straightforward as many geophysical measurements are inherently non-unique.

The challenges in drilling and sensing make orebody characterization among the most time and capital-intensive stages of resource valorization and mine development.

Methods that address these bottlenecks are critical to enabling faster, more accurate, and lower-cost assessment of U.S. REEs and other critical mineral resources.

C. PROGRAM OBJECTIVES

The ROCKS program seeks fundamentally disruptive technologies to transform the ore deposit characterization process. The program will pursue technology that targets order-of-magnitude improvements in characterization with a primary focus on drilling, sensing, and analysis. These advances will shorten the timeline for feasibility assessments of REE and critical mineral deposits, leading to increased access to these resources. In addition, advances in sensing can aid assessment of currently untapped resources, such as seafloor mineral deposits.

By facilitating mine development and increased access to domestic mineral resources, the program furthers ARPA-E’s statutory goals to improve the energy security of the U.S., ensure resilient and reliable supply chains for energy-relevant materials, and maintain U.S. technological leadership in critical mineral resource development.

D. TECHNICAL CATEGORIES OF INTEREST

The ROCKS program seeks technologies that improve the characterization of critical mineral resources, with an emphasis on REEs.18 Technologies of interest are grouped into three main categories: (1) drilling technology to increase penetration rates and core recovery; (2) sensing and analysis technologies to provide higher-resolution mineralogical and geochemical information, in situ or at a distance; and (3) other unique

18 As per ref. 1 and 2, a “critical mineral” in this document refers to: a critical mineral, as defined by 30 U.S.C. 1606(a)(3), as well as uranium, copper, potash, gold, and any other element, compound or material as determined by the Chair of the National Energy Dominance Council (NEDC). As per ref. 3, a REE refers to one of the 15 lanthanide series elements plus scandium and yttrium.

https://arpa-e.energy.gov/faqs

Questions about this NOFO? Check the Frequently Asked Questions available at https://arpa-e.energy.gov/faqs. For questions that have not already been answered, email ARPA-E-CO@hq.doe.gov (with NOFO name and number in subject line). Problems with ARPA-E eXCHANGE? Email ExchangeHelp@hq.doe.gov (with NOFO name and number in subject line).

- 13 -concepts that disrupt the current state of resource characterization for hard rock settings as well as REE-enriched clays, placer deposits, and seafloor resources.

1. CATEGORY A: DRILLING TECHNOLOGY

Category A targets technologies that dramatically increase drilling speed and improve efficiency while maintaining or improving core quality with the goal of significantly accelerating orebody characterization throughput.

Objectives of Category A include the following:

• Increase penetration rates in hard-rock drilling with coring to reduce total drilling time;

• Lower drilling costs per volume of rock characterized, including both drilling and mobilization costs;

• Enable high recovery and quality of continuous core, maintaining the integrity needed for mineralogical, geochemical, and textural analysis; and

• Enable swift decision making by generating useful data during drilling or coring processes that are available in near real-time.

Technologies of interest include, but are not limited to, the following:

• Adaptation of state-of-the-art techniques (e.g., sonic) from adjacent fields (e.g., geothermal, oil and gas, or geotechnical) to increase penetration speed while maintaining hard-rock coring capabilities and needs;

• Advanced drilling designs or methods (e.g., automation, directional, control systems, and sensors) that are optimized for high penetration and longevity in complex orebodies;

• Automation and remote monitoring systems to optimize drilling parameters, reduce manual intervention, reduce costs, and improve consistency across drilling campaigns; and

• Hybrid and energy-based drilling approaches that integrate high-speed, non-core drilling (e.g., microwave, laser, plasma, or thermal spallation) with simultaneous characterization and/or periodic core recovery for ground truthing.

2. CATEGORY B: SENSING AND ANALYSIS

Category B targets enhanced sensing and analytical capabilities to deliver significant improvements in resolution, sensitivity, and confidence of orebody characterization, while also reducing the time and cost of analysis. This category includes on-site core scanning/analysis, in situ borehole measurements, and remote measurements.

Objectives of Category B include the following:

• Improve spatial resolution and sensitivity of mineralogical and geochemical measurements, both in boreholes and on extracted core samples;

https://arpa-e.energy.gov/faqs

Questions about this NOFO? Check the Frequently Asked Questions available at https://arpa-e.energy.gov/faqs. For questions that have not already been answered, email ARPA-E-CO@hq.doe.gov (with NOFO name and number in subject line). Problems with ARPA-E eXCHANGE? Email ExchangeHelp@hq.doe.gov (with NOFO name and number in subject line).

- 14 -

• Improve measurements (especially discrimination of mineralogy) between boreholes or under 100 meters or more of cover;

• Accelerate data turnaround time, enabling near real-time decision-making and reducing delays from offsite laboratory analysis; and

• Improve imaging analysis, decision analysis, and value of information.

Technologies of interest include, but are not limited to, the following:

• Real-time measurements:

o MWD sensor systems for continuous downhole acquisition of drilling parameters to improve drilling and orebody understanding; and o In situ downhole and surface measurements for whole rock composition, mineralogy, geomechanical properties, and structural characterization.

• Improvements in sensitivity and resolution of geophysical, geochemical, or hybrid sensing methods:

o Novel signal sources (e.g., portable muon source, continuous seismic or electromagnetic);

o Borehole, cross-borehole, surface/borehole hybrid, surface, or aerial surveying methods for measuring unsampled areas with emphasis on mineralogy; and o Seismic methods, such as ambient noise, that use novel instrumentation (e.g., distributed acoustic sensing, rotational sensors, laser vibrometry) or deployments (in boreholes as well as at surface) for detailed hard-rock subsurface models.

• Advanced non-destructive geochemical sensors capable of probing mineralogy beyond the borehole wall, reducing the need for physical sampling;

• On-site core analysis methods (e.g., high-resolution hyperspectral and multispectral imaging, spectrometers) capable of generating on-site mineralogical datasets that are combined with advanced data pipelines;

• Innovative methods…