CO2 Microwave plasma increases yield of lithium

A common method of extracting lithium is to mix sodium carbonate (Na2CO3) to saltwater that contains lithium and extracting lithium carbonate (Li2CO3).

This method requires an additional process to separate the lithium carbonate from sodium impurities that blend during the extraction process. An alternative method uses carbon dioxide instead of sodium carbonate, but extraction rates are low.

Now, KFE’s Dr Ji Hun Kim and Dr Jong keun Yang have utilised carbon dioxide microwave plasma technology to increase the rate of lithium extraction.

They report that direct injections of carbon dioxide yielded a 10.3 per cent lithium extraction rate, while experiments using carbon dioxide plasma saw a 27.87 per cent return.

Plasma generation was achieved using a 2.45 GHz microwave plasma torch and the amount of remaining lithium in the aqueous solution before and after the reaction was quantified and analysed by inductively coupled plasma mass spectrometry. 

MORE FROM MATERIALS

According to KFE, this is the first research that demonstrated an increase in lithium extraction rates by applying plasma technology to the lithium extraction process. The work is detailed in Desalination.

In a statement, first author Dr Yang said: “It was possible to confirm the effects of the heat and ions, electrons, radicals et cetera that are generated when carbon dioxide plasma forms on lithium extraction rates. We plan to expand research into plasma lithium extraction processes through additional research into carbon dioxide plasma reactions.”

KFE president Suk Jae Yoo added: “This research shows a new possible use for plasma technology, which has been used extensively in cutting-edge fields such as semiconductors. Lithium obtained from seawater is a crucial component of fusion energy generation, and we will continue to conduct research into both fusion energy development and fusion energy fuel acquisition.”