2025.09.29 PRESS RELEASE

Launch of Demonstration Experiment for the Joint Development of Microwave-based Low-carbon Lithium Ore Refining Technology

Mitsui & Co., Ltd.
Microwave Chemical Co., Ltd.

Mitsui & Co., Ltd. (“Mitsui”, Head Office: Tokyo, President and CEO: Kenichi Hori) and Microwave Chemical Co., Ltd. (“MWCC”, President and CEO: Iwao Yoshino) will initiate a demonstration experiment using a pilot plant under the agreement of the joint development of microwave-based low-carbon lithium ore refining technology.

The use of electric power in the mobility sector is expanding as part of the transition to a carbon-neutral society. Many countries have designated lithium as a critical mineral1 because of its use in EV batteries, and there is also an increasing need to establish reliable supply networks for lithium from an economic security perspective. Lithium ore is refined using heat generated through fossil fuel combustion, and there is concern about the reduction in the large amounts of CO2 emitted during the calcination process. Therefore, it is anticipated that there will be growing demand for low-carbon lithium produced in ways that minimize the environmental impact.

The purpose of this joint development project, which was announced on June 27, 2023, is to electrify the calcination2 process—the main source of CO₂ emissions in lithium refining—and to establish the world’s first lithium refining technology using eco-friendly microwave technology and explore the potential for the implementation of this technology at new lithium mines and refining plants. In order to increase the scale of this technology, a pilot plant for conducting the demonstration experiment has been completed at the MWCC plant based in Osaka.

The newly completed pilot plant


This pilot plant will continuously calcine lithium ore by using a microwave heating unit. In addition to a significant reduction in CO₂ emissions, this method will also deliver energy savings through improved thermal efficiency. The next step will be to use this plant to conduct a demonstration experiment with a capacity of approximately 700 tons per year, in preparation for commercialization by around 2030.

Mitsui aims to achieve net‑zero emissions by 2050 and to halve its greenhouse gas impact by 2030 compared with the level in the fiscal year ended March 2020. Through this project, Mitsui will contribute to the realization of a carbon-neutral society by establishing a reliable lithium supply chain.

MWCC sees the real-world implementation of this new lithium ore refining technology as a step toward the achievement of carbon neutrality under its C NEUTRAL™ 2050 Design concept, and as a way to realize its vision “To reinvent a chemical industry which has remained unchanged over a century and transform the world of manufacturing. To make the microwave process a global standard.”

1    The Act on the Promotion of Ensuring National Security through Integrated Implementation of Economic Measures in Japan and the Inflation Reduction Act in the United States, etc.
2    A heat treatment process in which ore is heated at high temperatures to alter its chemical composition and crystal structure.


Mitsui’s Mineral & Metal Resources Business Unit

The Mineral & Metal Resources Business Unit has been working since the 1960s to ensure stable supplies of metal resources to Japan and other markets around the world through the active development of iron ore and coking coal resources. It has also prioritized the development of non‑ferrous metal resources, such as copper, nickel, and aluminum, and in recent years it has initiated lithium projects in response to rapid demand growth. For this joint development project, Mitsui will use its global network and expertise in the mining business to identify its customers’ decarbonization needs and promote the use of this low‑carbon lithium ore refining technology in overseas markets.


MWCC’s Activities in the Mining and Metal Refining Process Fields

In 2014, MWCC successfully developed the world’s first manufacturing process in which microwaves are used to heat materials at a large-scale chemical plant. The company has been contributing to the achievement of carbon-neutrality by providing revolutionary electrification processes for use in the chemical sector and a wide variety of other industries.

In recent years, it has created the Green Mining‑MX microwave technology platform for mining and metal refining processes and is now developing new refining technologies based on the use of microwave heating to save energy and reduce CO2 emissions.