Direct Lithium Extraction from α-Spodumene through Solid-State Reactions for Sustainable Li₂CO₃ Production

Area of Science:

• Materials Science
• Chemical Engineering
• Mineral Processing

Background:

• Growing demand for lithium-ion batteries necessitates alternative lithium (Li) sources beyond traditional brines.
• Spodumene is a key Li-bearing mineral, but conventional processing is energy-intensive and costly.
• Current methods involve high-temperature phase transformation and acid leaching, posing environmental and economic challenges.

Purpose of the Study:

• To develop a novel, energy-efficient, and acid-free method for direct lithium carbonate (Li2CO3) extraction from alpha-spodumene.
• To investigate the reaction mechanism and optimize conditions for Li2CO3 yield.
• To provide a sustainable alternative for lithium sourcing to meet increasing battery demands.

Main Methods:

• Direct reaction of alpha-spodumene with sodium carbonate (Na2CO3) and aluminum oxide (Al2O3) at 750°C.
• Optimization of reaction time to maximize Li2CO3 yield.
• Isolation of Li2CO3 via deionized water washing.

Main Results:

• Achieved >90% yield of Li2CO3 by reacting alpha-spodumene with Na2CO3 and Al2O3 at 750°C.
• Demonstrated that Al2O3 addition is critical to suppress Li2SiO3 formation and promote Li2CO3 and NaAlSiO4 as sole products.
• Identified 4 hours as the optimal reaction time, beyond which yield is limited by volatility.

Conclusions:

• The developed method offers an energy-saving and acid-free route for direct Li2CO3 extraction from alpha-spodumene.
• This process can significantly contribute to diversifying lithium sources and meeting global battery demand.
• The findings present a viable alternative to conventional, high-temperature, and acid-intensive spodumene processing.