The contract covers the licence, engineering and supply of DuPont's proprietary equipment for ioneer's planned plant. DuPont will work with engineering partner SNC-Lavalin on the plant design, providing MECS sulphuric acid production technology for a plant with a capacity of 3,500t/d, and controls that limit emissions to what ioneer stated will be among the lowest in the world for this type of facility.
The plant will employ advanced technologies to meet stringent air quality standards and water pollution control. The plant's capability was an instrumental part in ioneer receiving a Class II Air Quality Permit by Nevada's Division of Environmental Protection Bureau of Air Pollution Control in June, which is a requirement to begin project construction. According to ioneer, it is the first sulphuric acid plant permitted in Nevada.
DuPont will also supply its latest generation MECS Super GEAR catalyst to the plant, along with other critical proprietary equipment. The plant at Rhyolite Ridge will convert sulphur into commercial-grade sulphuric acid, which will then be used to leach lithium and boron from the crushed rock.
Electricity will be generated by recovering the heat released in the process and producing steam. An initial 35MW will be generated by the plant, which is enough to power the entire operation at Rhyolite Ridge, meaning ioneer will not need to draw electricity from the grid. ioneer stated that Rhyolite Ridge will be an energy-independent operation that will use primarily co-generated, zero-carbon power.
In addition, the evaporation and crystallisation processes that produce lithium carbonate and boric acid will use some of the generated heat.
DuPont's contract for the sulphuric acid plant is conditional on the ioneer board of directors' final investment decision on the project.
Once operational, the Rhyolite Ridge project is predicted to produce 20,600t/y of lithium carbonate, converting in the fourth year to 22,000t/y of battery-grade lithium hydroxide, and 174,400t/y of boric acid. The project is expected to begin production in the second half of 2024, pending final federal US Department of the Interior (DOI) approval of the plan of operation.
Bernard Rowe, managing director of ioneer, commented: "Development of the Rhyolite Ridge lithium-boron project is a critical strategic step to enable US production of lithium-ion batteries for electric vehicles (EV) and renewable energy storage. ioneer's core commitment is to produce essential materials in an environmentally and socially responsible and sustainable manner through lowered emissions, reduced water usage and a minimal surface footprint. We are delighted to welcome MECS-DuPont to our team. It is a world-leader in clean technology and emissions control and will work alongside ioneer to deliver this tier-1 project in the US."
Eli Ben-Shoshan, global business leader of DuPont Clean Technologies, said: "We have worked in close partnership with ioneer and SNC-Lavalin to be able to guarantee the precise performance and emissions control ioneer needs for its Rhyolite Ridge project to meet stringent environmental standards and production objectives. We are excited to be part of a project that helps ioneer cleanly produce lithium essential to advancement of electric energy markets and to be able to support it with our many decades of expertise in sulphuric acid plant technology."
In November 2019, DuPont supplied its MECS sulphuric acid technology for NioCorp's superalloy materials project in Elk Creek, Nebraska, US.
