Recovery of lithium from mineral resources: State-of-the-art and perspectives – A review

A review on methods for liberating lithium from pegmatities

An effective method using hydrofluoric and sulfuric acid was proposed to enhance the leaching of lithium from α-spodumene, without calcination that is subjected to 1000 °C for phase transformation. The thermodynamic feasibility of the reactions was firstly verified. Dissolution conditions were tested to maximize the leaching efficiency of lithium and with efficient utilization of hydrofluoric acid (HF) served as evaluation criteria. The results showed that 96% of lithium could be transferred into lixivium with an ore/HF/H2SO4 ratio of 1:3:2 (g/mL/mL), at 100 °C for 3 h. Due to the fact that HF molecules were the main reaction form, the dissolution behaviors were theoretically represented and investigated by dissolution in HF/H2SO4. When combined with chemical elements analyses and characterizations, the results of the dissolution behaviors revealed that α-spodumene and albite were preferentially dissolved over quartz. Insoluble fluoroaluminates, such as AlF3, cryolite (Na3AlF6) and cryolithionite (Na3Li3Al2F12), were generated and might be further partially dissolved by H2SO4. Fluorosilicates, such as K2SiF6, Na2SiF6, or KNaSiF6, were also generated as a part of the insoluble residues. This work provides fundamental insight into the role of HF/H2SO4 played in the dissolution of α-spodumene, and sheds light on a novel and promising process to efficiently extract lithium.

Investigation of Enhanced Leaching of Lithium from α-Spodumene Using Hydrofluoric and Sulfuric Acid

A promising approach for directly extracting lithium from α-spodumene by alkaline digestion and precipitation as phosphate

Spodumene is the main source of lithium among the lithium-containing minerals. A number of studies have been done on the extraction of lithium from naturally occurring α-spodumene as well as pre-tr...

Production of Lithium –A Literature Review. Part 2. Extraction from Spodumene

In order to decrease lithium extraction cost, pollution and energy. A new and efficient technology was particularly discussed in this paper, the fluorine chemical method to extract lithium from spodumene. The reaction mechanism had also been analysed by studying the crystal structure variation and reaction products. The results show that hydrofluoric acid corroded α-spodumene in low temperature, damaged the compact chemical bonds: Li-O, Al-O, Si-O, and Al-O-Si, and generated Li3AlF6 and AlF3, which can be dissolved in sulfuric acid. Our research provides theoretical guidance for the lithium extraction process from α-spodumene.

Zhi Bin Chen

Papers

Lithium Extraction Mechanism from α-Spodumene by Fluorine Chemical Method