EXPRESS: Electric-Field Assisted Laser-Induced Breakdown Spectroscopy (LIBS) for the analysis of Li Ore

The X-ray fluorescence (XRF) spectroscopy is widely used in mining for elemental analysis, but it cannot detect lithium (Li) due to its low atomic number. The low sensitivity and high detection limits of conventional laser-induced breakdown spectroscopy (LIBS) also present serious challenges for analyzing lithium ore. This work demonstrates improved analytical capabilities of LIBS by using an external electric field to detect Li and other trace elements in Li ore. A notable increase in emission intensity and detection sensitivity for all trace elements has been observed in electric field-assisted LIBS (EF-LIBS) compared to conventional LIBS. Significant changes in plasma parameters, such as stabilized electron density and an extended plasma lifespan (∼10 μs), were achieved by applying the electric field, resulting in better spectral signals. The most impressive improvement was an eightfold increase in the detection limit for lithium, which decreased from 46.07 ppm (traditional LIBS) to 5.93 ppm (EF-LIBS). Increased excitation efficiency under the electric field and a longer plasma plume lifetime are responsible for this enhancement. For lithium exploration and mining, EF-LIBS offers a better alternative to traditional methods due to its field-deployable design and low sample requirements, providing increased sensitivity and operational advantages without the need for additional complex equipment.