In This Issue
Winter Bridge on Frontiers of Engineering
December 15, 2023 Volume 53 Issue 4
This issue features articles by 2023 US Frontiers of Engineering symposium participants. The articles cover pressing global issues including resilience and security in the information ecosystem, engineered quantum systems, complex systems in the context of health care, and mining and mineral resource production.

Securing the Green Revolution The Modern Mining of a Domestic Lithium-Boron Deposit

Wednesday, December 13, 2023

Author: Nina Astillero and Alex Tshibind

Sustainability in lithiumxq production is not merely a desirable goal; it is an imperative for fostering a greener future.

As societies worldwide pivot towards electric vehicles, lithium-ion batteries stand as the cornerstone of energy storage. Mining, often met with societal apprehension, becomes an inextricable part of this transition, unearthing raw materials like lithium and boron. These elements are the lifeblood of the green revolution, enabling the production of batteries that drive the clean energy paradigm. Striking a delicate balance between meeting rising demand and minimizing social and ecological impact is imperative. Thus, understanding and optimizing the processes involved in mining and lithium processing becomes not just a technological necessity but a moral obligation in order to forge a sustainable path towards a decarbonized future.

Astillero figure 1.gifThough lithium is understood to be an integral part of the energy revolu­tion, the United States does not currently have a ready supply. Several ­lithium development projects are in the western United States. One of the most advanced projects is ioneer’s Rhyolite Ridge Lithium-Boron Project located in Esmeralda County, Nevada (figure 1). The project will produce over 20,000 metric tons per year of lithium carbonate (quadrupling the current US domestic production capacity) and 174,000 metric tons of boric acid. Lithium carbonate is a key ingredient in battery production for ­electric vehicles, and stationary energy storage is critical to the ongoing global electrification and decarbonization effort. Production from the project will be sufficient for approximately 400,000 electric vehicles per year. Boric acid is also crucial for decarbonization and is used in electric vehicle (EV) components such as permanent magnets and solar panel specialty glass (Fluor Enterprises, Inc. 2020).

Rhyolite Ridge at a Glance: Sustainable Processing

The Rhyolite Ridge Lithium-Boron Project not only ­produces critical minerals required for the ongoing ­decarbonization efforts, but the selected technologies enable the production of these minerals in a sustainable manner. The development will consist of open-pit ­mining, a production facility, and a sulfuric acid plant.

A high-level description of the processing facility with major unit operations is shown in figure 2. Once received by the plant, the ore will go through different crushing stages to obtain a suitable size for leaching. This later stage will consist of seven different vat leach tanks fed from the bottom up with concentrated sulfuric acid as the leaching solution. The resulting pregnant leach solution (PLS), containing solubilized lithium and other elements, will be sent to the chemical processing plant, where it will go through a combination of chemical purifications, crystallization, and evaporation stages to obtain final purified technical-grade lithium carbonate and boric acid.

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This entire process is done in a sustainable manner, with all the required power being produced on-site through a CO2-free process by recovering heat from ­exothermic reactions of sulfur combustion in the ­sulfuric acid plant. An autonomous haul truck fleet will be used in the open-pit mine, and several automated ­process ­control systems will be implemented to streamline the process and mining operations. This facility aims to achieve zero discharge by recycling and reusing about 50% of the water within the facility.

Ongoing operational improvement efforts are being conducted to reduce reagent consumption. This will reduce the burden associated with logistics and transport. These improvement efforts have also identified potential alternative technologies that will further reduce the overall water consumption. Additionally, studies are ongoing for the monetization of byproducts like magnesium and potassium sulfates. This will reduce the environmental footprint of the project particularly for carbon, water, and the physical footprint of the spent ore storage ­facility. (Fluor Enterprises, Inc. 2020).
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A Greenfield Has Been Located—Now What?

Before mining can begin, an extensive permit process is required.  As the project is situated on US federal land, ioneer is seeking approval from the federal government to begin construction at Rhyolite Ridge under the National Environmental Policy Act (NEPA). This NEPA process is administered by the Bureau of Land Management (BLM). In total, approximately thirty permits and licenses must be obtained prior to the commencement of construction and operation. Of the thirty approvals, the most significant are the state air permit, the state water permit, and a positive federal record of decision (ROD). The ROD incorporates an environmental impact statement (EIS) and is the culmination of the BLM’s NEPA process. The steps of the NEPA process are shown in figure 3.

What Happens to the Electric Vehicle Supply Chain and Sourcing in the Meantime?

Over the next decade, the growing demand and diffi­culty in bringing on supply present challenges, ­especially for the domestic supply chain. The soaring demand for ­lithium, fueled by the rapid expansion of EVs and the proliferation of stationary storage applications, highlights the existing fragility of the supply chain. As the world gravitates towards cleaner energy solutions, concerns arise regarding the insufficient capacity of lithium production to meet escalating requirements globally. The strain on the supply chain poses potential bottlenecks, impacting the transition to sustainable technologies and underscoring the urgent need for strategic investments and innovations to fortify the lithium ­supply chain against the burgeoning demand in the years ahead.

Global EV battery demand increased by about 65% in 2022, reaching around 550 GWh, about the same level as EV battery production. The lithium-ion automotive battery manufacturing capacity in 2022 was roughly 1.5 TWh for the year, implying a utilization rate of around 35% compared to about 43% in 2021.

Battery demand is set to increase significantly by 2030, reaching over 3 TWh in the stated policies scenario (STEPS) and about 3.5 TWh in the announced pledges scenario (APS). To meet that demand, more than fifty gigafactories (each with 35 GWh of annual production capacity) would be needed by 2030 in STEPS in addition to today’s battery production capacity. This increase is close to the 65 new gigafactories needed to meet 2030 demand in the APS. According to Benchmark Mineral Intelligence (as of March 2023), the announced battery production capacity by private companies for EVs in 2030 amounts to 6.8 TWh, plenty sufficient to meet demand in both STEPS and the APS. In the net zero by 2050 (NZE) scenario, battery demand reaches over 5.5 TWh in 2030 (figure 4). Assuming an average utilization rate of battery production facilities of 85%, the announced capacity in 2030 narrowly covers what is needed in the NZE scenario (IEA 2023).

China is expected to dominate demand for EV batteries up to 2025, in both STEPS and the APS. However, in the APS, China’s share of EV battery demand declines to about 35% in 2030 from over 55% in 2022, due to significant growth in EV sales in the United States, Europe, and other markets (figure 5).

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Responsible Mining and Sustainability

Like many other industries, mining is subject to increasing scrutiny related to sustainability and responsible practices. The first layer of responsible mining comes from compliance with strict environmental, safety, and governance regulations. Recall that the Rhyolite Ridge Lithium-Boron Project requires thirty permits and licenses to commence construction and operation. Typically, mining projects in the United States must have air, water, waste, reclamation, and land use permits. These permits dictate activities such as effluent and emission limitations, discharge volumes, and bonding for land restoration.

In recent times, a push for adhering to third-party standards outside of regulations has also been required. One of the typical third-party standards is the ISO14001 Environmental Management System. This system organizes the documentation of a company to demonstrate compliance and goal setting for environmental improvement. The system is audited periodically to ensure its effectiveness and adherence to the ISO14001 standard (IOS 2015).

From there, companies can adhere to sustainability management standards. An example is the Towards Sustainable Mining Initiative. Using this type of standard, a company must meet criteria put forth by the organization. In this case, member companies must follow protocols for activities such as indigenous and community engagement, water management, biodiversity management, and diversity and inclusion. The companies must self-report and are also audited by a third party.

Finally, companies adhere to sustainability reporting frameworks such as the Global Reporting Initiative (GRI). Reporting above and beyond compliance requirements traditionally covers a myriad of topics from diversity to cybersecurity, environmental performance, and employee safety (Global Reporting Initiative 2023). The reporting is published on a periodic basis, usually in a sustainability report.


The interplay among lithium supply, mining practices, and sustainability underscores the pivotal crossroads at which our pursuit of decarbonization stands. As the global auto industry shifts towards electric vehicles and stationary grid storage becomes more prominent, the demand for lithium will grow significantly.  Given the need to extract lithium, the mining industry finds itself at the forefront of environmental and social considerations. Balancing the need for resource extraction and refining with the conservation and protection of the environment requires innovative and sustainable ­mining practices. The vulnerability of the lithium ­supply chain reveals the urgency of investing in responsible sourcing. ­Sustainability in lithium production is not merely a desirable goal; it is an imperative for fostering a greener future. To satisfy these objectives, an integration of environmental stewardship, social responsibility, and technological advancements will be the linchpin for achieving a resilient and sustainable lithium ­supply chain that propels us towards a cleaner, low-carbon energy landscape.


Fluor Enterprises, Inc. 2020. Rhyolite Ridge Lithium-Boron Project Definitive Feasibility Study (DFS) Report. Online at summary/.

Global Reporting Initiative. 2023. Online at:

International Energy Agency (IEA). 2023. Global EV Outlook 2023. Online at, License: CC BY 4.0.

International Organization for Standardization (IOS). 2015. ISO 14001 Key Benefits. Online at en/PUB100372.pdf.

About the Author:Nina Astillero is ESG director and Alex Tshibind is senior metallurgist, both at ioneer, Ltd.