'Chinese Graphite' Becomes Purified with Domestic Technology

[Asia Economy Reporter Junho Hwang] There is a Chinese-made material that must be used in the lithium-ion batteries of smartphones and electric vehicles we use. It is graphite with 99.9% purity used as an anode material. This graphite market is shared between China and Japan, with Chinese natural graphite accounting for 65%. As the use of secondary batteries gradually increases, the demand for graphite is also surging. The demand for anode materials is expected to grow by 39%, from 190,000 tons last year to 1.36 million tons by 2025.

However, to obtain high-purity graphite, hydrofluoric acid must be used. Hydrofluoric acid is a toxic substance that can penetrate the skin or mucous membranes and cause death, requiring careful handling. Due to the risks of hydrofluoric acid leakage and environmental pollution from wastewater, governments of several countries including China have banned hydrofluoric acid refining methods. The problem is that there is no industrially viable refining method to replace hydrofluoric acid refining, making it difficult to meet the increasing demand for graphite.

Environmentally Friendly Refining of 99.99% Pure Graphite

KIGAM's eco-friendly high-purity graphite manufacturing technology reduces costs related to post-processing and wastewater treatment compared to conventional refining methods using sulfuric acid and hydrofluoric acid. By adding chelate leaching for impurity removal and a low-temperature soda roasting process, it is an environmentally friendly and efficient manufacturing technology.

Dr. Heedong Jang’s research team at the Resource Utilization Research Center, Mineral Resources Research Division of the Korea Institute of Geoscience and Mineral Resources recently developed an eco-friendly graphite manufacturing method at the request of a company facing such difficulties.

It is a wet refining method consisting of hydrochloric acid leaching, chelate leaching, and low-temperature soda roasting processes. By determining the optimal amount of reagents, reaction temperature, and reaction time for each process, graphite with a purity of over 99.99% can be produced.

The biggest advantage of the newly developed refining method is that it does not require the use of hydrofluoric acid. There is no need for post-treatment processes, and no wastewater is generated. It is an eco-friendly process that also reduces graphite production costs. Since no post-treatment costs are incurred, graphite can be produced at about 70% of the cost of the conventional hydrofluoric acid refining method.

The purity of graphite can also be increased compared to hydrofluoric acid refining. While hydrofluoric acid refining can produce graphite with 99.9% purity, the new refining method can produce graphite with 99.99% purity. As the purity of graphite increases, improved performance and extended lifespan as an anode material are expected.

Technology Transfer Domestically and to China

Dr. Jang Heedong (center) and the research team are conducting an eco-friendly high-purity graphite refining process.

Dr. Jang said, “The eco-friendly high-purity graphite manufacturing technology developed this time is a refining technology that produces graphite with the highest purity of over 99.99%, higher than the existing 99.9% purity.” He added, “Based on the advantages of eco-friendliness and economic feasibility, we plan to enhance the technology’s utility through technology transfer to countries such as China.”

Kim Bokcheol, President of the Korea Institute of Geoscience and Mineral Resources, said, “The development of eco-friendly high-purity graphite manufacturing technology is an excellent research achievement that can be effectively applied to next-generation energy materials in the era of the 4th Industrial Revolution.” He added, “We will spare no support to ensure that this technology is usefully utilized not only domestically but also internationally through technology transfers.”

This content was produced with the assistance of AI translation services.