Coupled reaction and solvent extraction process to form Li₂CO₃: Mechanism and product characterization

Abstract

A coupled reaction and solvent extraction process to produce Li2CO3 from LiCl and CO2 is proposed. The aqueous reaction occurs with difficulty and is not spontaneous at 298 K. To ensure the continuous reaction between LiCl and CO2 to produce Li2CO3, it is necessary to remove HCl. Experiments conducted in an open reactor at room‐temperature showed that the product sample was pure Li2CO3 with a particle‐size distribution in two regions and a larger number of small crystals. The large and small crystals were obtained by radial growth in the free aqueous phase and in water‐in‐oil structures with growth space constraints, respectively. Factors influencing the particle‐size distribution and Li2CO3 morphology were investigated. A short reaction time, large phase ratio (O/A), low–temperature, and surfactant addition (TritonX‐100) can increase the number of small particle crystals and reduce the number and volume of large particle crystals. © 2013 American Institute of Chemical Engineers AIChE J, 60: 282–288, 2014

Lithium Enrichment of High Mg/Li Ratio Brine by Precipitation of Magnesium via Combined CO2 Mineralization and Solvent Extraction

“…When CO 2 is used as the precipitant, the reactions include the hydration of CO 2 and the ionization of H 2 CO 3 . These reactions can be expressed as − where k 7 , k 8 , k 9 , and k 10 are the reaction equilibrium constants. According to the literature, , the values of k 7 and k 10 are 3.43 × 10 –2 and 4.69 × 10 –11 , respectively.…”

Selective removal of magnesium from lithium‐rich brine for lithium purification by synergic solvent extraction using β‐diketones and Cyanex 923

“…Magnesium (Mg) always accompanies Li in salt lake brines, consequently Mg impurities are often found in Li 2 CO 3 . The typical process for the production of Li 2 CO 3 from brines includes: (a) concentration of brines by evaporation in a solar pond for about 1 year, (b) removal of Mg by lime milk (Ca[OH] 2 ) and (c) removal of calcium by addition of Na 2 CO 3 /Li 2 CO 3 , and finally (d) precipitation of Li 2 CO 3 by addition of Na 2 CO 3 13‐15 . Li 2 CO 3 produced from this process is of technical‐grade (~99%), but it is difficult to reach battery‐grade (>99.5%) and high‐purity (99.99%) Li 2 CO 3 16 .…”

Mechanism studies on thermal dissociation of tri-n-octylamine hydrochloride with FTIR, TG, DSC and quantum chemical methods

“…As effective extractants, high molecular mass aliphatic water-insoluble amines, especially tertiary amines such as tri-n-octylamine (TOA), tris-(2-ethylhexyl)-amine (TEHA), N235 (a mixture of tertiary amines with carbon number 8 to 10 in each chain), are used for the extraction of HCl directly from HCl-containing solutions [1][2][3][4][5][6][7][8][9] or in the reactive extraction-crystallization coupled process of CaCl 2 , [10][11][12][13] MgCl 2 , 13,14 SrCl 2 , 15 LiCl, 16 etc. (converting them to their respective carbonates by introducing CO 2 and amine extractants, such as TOA).…”