Literature Review and Thermodynamic Modelling of Roasting Processes for Lithium Extraction from Spodumene

Abstract

This review adds to the public domain literature on the extraction of lithium from mineral ores. The focus is on the pyrometallurgical pre-treatment of spodumene. Information on the phase transformation from α to β, the heat treatment methods as well as the behavior of various compounds in the roasting processes are evaluated. Insight into the chemical thermodynamics of the baking process is evaluated using HSC Chemistry software up to 1200 °C. It was observed that the alkaline, sulfation, chlorination (using Cl2 and CaCl2), carbonizing (to form Li2CO3) and fluorination processes were feasible either throughout or at a point within the temperature range considered. Chlorination using KCl and carbonizing to form Li2O are the processes found to be nonspontaneous throughout the temperatures considered.

Electro-Driven Materials and Processes for Lithium Recovery—A Review

“…During acid/sulfonation processes, alkali metal sulfates, sulfuric acid, or SO 3 gas mixed with water and oxygen are employed as reagents to produce highly water-soluble Li sulfates that are less prone to precipitation compared to other Li compounds. However, drawbacks include the large volumes of reagent chemicals required and challenges in producing high-purity Li carbonates from such brines resulting from the capacity of sulfate reagents to bind to Al, Na, Mg, Fe, and K [ 2 , 36 ]. The sulfate roasting of lepidolite followed by water leaching has been studied widely using Na 2 SO 4 /K 2 SO 4 /CaO, Na 2 SO 4 , and Fe S O 4 and has yielded Li extraction extents up to 99.5% at 1000 °C [ 37 , 38 , 39 ].…”

Novel extraction route of lithium from α-spodumene by dry chlorination

“…Owing to the inherent advantages of chlorination, it promises an efficient approach for processing the mineral. After a thorough review of literature by Fosu et al 34 on processes used so far to recover the metal from spodumene, their thermodynamic modelling highlighted chlorination as one of the promising processes which has had the least of attention. In 1959, Peterson et al 35 patented the possible extraction of lithium from α-spodumene using an alkali metal halide or their mixture (specifically, KCl and/or NaCl) in the presence of a refractory material.…”

Physico-Chemical Characteristics of Spodumene Concentrate and Its Thermal Transformations

“…Lithium is sequentially extracted from spodumene via three processes namely decrepitation, roasting to form soluble salt by sulfation, carbonation, chlorination or fluorination [ 9 ]; followed by water leaching of the products of roasting to form an aqueous lithium solution. During decrepitation, the mineral is roasted at high temperatures (above 800 °C) to convert the monoclinic α form to the tetragonal β form.…”