Influence of Inorganic Solution Components on Lithium Carbonate Crystal Growth

Abstract

Lithium-bearing brines are an increasingly attractive source of Li for extraction. One extraction mechanism is the removal of Li from the fluid phase through the precipitation of zabuyelite (Li2CO3). The chemistry of the brine plays an important role in this process because ions in solution can compete for the components of the Li-carbonate phase. Here we explore the effect of different brine components on the precipitation of zabuyelite using experiments and computational simulations. Crystals formed in all solutions showed morphological evidence for potential transformation from a precursor phase. Our study indicates that Ca2+ and SO42– are incorporated into the precipitated zabuyelite crystals. Sulfate also interacts directly with specific surfaces on the growing crystal and is expected to form ion pairs with Li+ in solution. Similarly, Na+ appears to form ion pairs in solution with the carbonate ion, slowing nucleation of zabuyelite in the experiments. K+ and Cl– may interact with the growing zabuyelite crystals but do not appear to affect zabuyelite nucleation and growth times. These experiments highlight the importance of understanding the solution chemistry on zabuyelite formation in order to predict the efficiency of extraction processes and the purity of the solids.

Recovery of Lithium Carbonate from Dilute Li-Rich Brine via Homogenous and Heterogeneous Precipitation

“…From Figure , it can be seen that the Li 2 CO 3 precipitation rate considerably decreases in the presence of sulfate, in accordance with the reported delaying effect of sulfate ions on Li 2 CO 3 (s) nucleation . The delaying effect is reduced in high-ionic strength solutions, although no precipitation occurs within the experiments time; thus, no recovery and purity were calculated.…”

“…In all cases, it must stress that, Ca 2+ , Sr 2+ , and Mg 2+ carbonate compounds have a low solubility that likely causes a CO 3 2− consumption. This is also confirmed by results presented by King et al 32 that detected traces of CaCO 3 and MgCO 3 in Li 2 CO 3 compounds precipitated from Li solutions containing 0.033 M Ca 2+ and Mg 2+ . The simultaneous presence of the three interfering cations (Ca 2+ , Sr 2+ , and Mg 2+ ) inhibits Li 2 CO 3 precipitation, most likely due As already commented in Figure 6, Li + recovery can reach a value around 70% for high-ionic strength solutions without any divalent ions.…”

“…From Figure 10, it can be seen that the Li 2 CO 3 precipitation rate considerably decreases in the presence of sulfate, in accordance with the reported delaying effect of sulfate ions on Li 2 CO 3 (s) nucleation. 32 The delaying effect is reduced in highionic strength solutions, although no precipitation occurs within the experiments time; thus, no recovery and purity were calculated. It is worth noting that the dissolution of Na 2 SO 4 salts also causes a salting-in effect that, in turn, leads to a Li 2 CO 3 solubility increase, affecting the overall precipitation process.…”

Lithium recovery from pretreated α‐spodumene residue through acid leaching at ambient temperature

“…[48] In particular, the Ca 2+ could compete with Li + for CO 3 2+ to form CaCO 3 , resulting in insufficient precipitation of Li 2 CO 3 . [49,50] Therefore, reducing the leaching of impurity ions is necessary for the precipitation of Li 2 CO 3 . [51,52] Calcium oxide was first added to remove Mg 2+ and SiO 3 2À :…”

Advantages of pH and Temperature Control in the Carbonation Stage for Li2CO3 Production with Sulphated Liquors

“…[21] It is possible that the difference between the theoretical solubility data reported in the literature for Li 2 CO 3 and the experimental results found in this work can be explained by the different chemical composition of the aqueous solutions. King et al [22] found that the composition of the aqueous solution contributes either positively or negatively to the formation of Li 2 CO 3 and demonstrated, using experiments and computational simulations, that low concentrations of Na + ions have minimal influence on the precipitation of Li 2 CO 3 . However, if the Na + concentration is increased to 1 M, the time required for the precipitation of Li 2 CO 3 increases.…”